book of abstractsinfo.ifpan.edu.pl/ml2015/en/files/ml2015_boa.pdfconference program molecules and...

Molecules and Light 2015 III Autumn Meeting of the Polish Photochemistry Group

Zakopane, 28 September - 2 October 2015

Book of Abstracts

Institute of Physics PAS, Warsaw Jagiellonian University, Kraków

Adam Mickiewicz University, Poznań

http://www.ifpan.edu.pl/ml2015/

http://www.ifpan.edu.pl/ml2015

Molecules and Light 2015, Zakopane 28 September - 2 October 2015

Official conference web site: http://www.ifpan.edu.pl/ml2015/

Important Information Conference venue: Hotel Hyrny, Zakopane, ul. Piłsudskiego 20 Tel.: +48 18 20 155 75, http://www.fwp.zakopane.pl/ (all lectures, communications, panel discussion and

poster session)

Welcome Dinner: Hotel Hyrny, Zakopane, ul. Piłsudskiego 20 28 September 2015

Excursion: Belianska Cave, Slovakia 30 September 2015

Conference Dinner: Karczma Czarci Jar, Zakopane, ul. Małe 1 October 2015 Żywczańskie 11a Tel.: +48 18 20 641 78, www.czarcijar.pl

Edition: Jerzy Karpiuk Institute of Physics, Polish Academy of Sciences, Warsaw Jagiellonian University, Kraków Adam Mickiewicz University, Poznań

All rights reserved.

http://www.ifpan.edu.pl/ml2015


Molecules and Light 2015 III Autumn Meeting of the Polish Photochemistry Group

Zakopane, 28 September - 2 October 2015

Organizing Committee

Conference Chairman

Jerzy Karpiuk (Institute of Physics PAS, Warsaw)

Members

Wojciech Macyk (Faculty of Chemistry, Jagiellonian University, Kraków)

Marek Sikorski (Faculty of Chemistry, Adam Mickiewicz University, Poznań)

Olaf Morawski (Institute of Physics PAS, Warsaw)

Łukasz Orzeł (Faculty of Chemistry, Jagiellonian University, Kraków)

Ewa Kuliś (Faculty of Chemistry, Jagiellonian University, Kraków)

Edyta Majsterek (Institute of Physics PAS, Warsaw)

Sponsors and exhibitors

The ML2015 Meeting is sponsored by the Leading National Research Centre KNOW (Krajowy Naukowy Ośrodek Wiodący KNOW)

Exhibitors

COMEF Aparatura Naukowo-Badawcza, Katowice

EUROTEK International, Warsaw

SHIM-POL, Izabelin

Table of Contents


Table of Contents

Important Information ......................................................... 2

Organizing Committee ........................................................ 3

Exhibitors ............................................................................ 3

Welcome .............................................................................. 5

Conference Program........................................................... 6

Plenary Lectures ............................................................... 11

Invited Lectures ................................................................ 17

Panel Discussion .............................................................. 23

Oral Communications ....................................................... 29

Exhibitor presentations .................................................... 49

Posters............................................................................... 51

Welcome


Welcome Dear Colleagues and Friends, After two ML meetings, four and two years ago, we have again the honour and pleasure to welcome you in Zakopane to attend the Molecules and Light 2015 Conference. It was your very positive response to ML2011 and ML2013 which made us believe that the meeting is really needed by our community. When we started to organise the ML2011 with Marek Mac, we did not expect the initiative to be so viable. I (JK) still remember Marek's and my doubts and questions we were discussing on a beautiful sunny day in May 2011, on our travel to Zakopane to set up the first ML. Today, to our deep regret, Marek is not with us, he suddenly passed away just a few days ago, on 21 September, 2015. Marek, thank you for what you have done, we will miss you very much.

The 'International Year of Light 2015' gives us special reasons for celebrating interactions between light and matter. As our two past meetings, the confer-ence aims at reviewing current research conducted in Poland in the field of photochemistry, photophysics and luminescence studies, and at providing opportunity for establishing and strengthening contacts between the members of our community. This year's edition will emphasise both theoretical and ex-perimental aspects of photophysical and photochemical research. We organ-ise the meeting under the auspices of the European Photochemistry Associa-tion, as the Polish Section of the EPA, as we feel it is an excellent platform to combine national review of our field with an international perspective. We keep organising Molecules and Light as the Autumn Meeting also because we be-lieve that the autumn colours of Nature are especially suitable for stimulation and inspiration with new concepts and ideas on molecules and light.

The present meeting is a joint effort of three institutions: the Institute of Phys-ics of the Polish Academy of Sciences, the Jagiellonian University and the Adam Mickiewicz University, and we sincerely acknowledge their support. We thank also our exhibitors and sponsors for their contributions.

Traditionally, we wish you inspiration, stimulation and breaking new ground during ML2015. We also hope that you will enjoy numerous attractions of the capital of Polish Tatra Mountains. Jerzy Karpiuk, Wojciech Macyk, Marek Sikorski

28 September 2015, Zakopane

Conference Program


Conference Program

Monday, 28 September, 2015

Monday, 28 September, 2015:

14.00-19.00 Registration

Monday, 28 September 2015

Evening Session: 19.00-23.00

Nanoscale light-matter interactions

Opening Session

19.00-19.15 Welcome address and conference opening

19.15-20.15 Opening lecture

Marek Samoć, Wrocław University of Technology, Wrocław

Nonlinear absorption of light by molecules and nanoobjects

20.15-23.00 Welcome dinner

Tuesday, 29 September 2015


Morning Session: 9.00-13.00

Excited state dynamics

9.00-10.00

PL1

Mike Ashfold, School of Chemistry, University of Bristol, Bristol

Molecular photofragmentation dynamics in the gas and condensed phases: similarities and differences

10.00-10.30

OC1

Michał Rode, Institute of Physics, Polish Academy of Sciences, Warsaw

ESIPT-based mechanisms of molecular photoswitching

10.30-11.00 Coffee break

11.00-11.45

IL1

Tolga N. V. Karsili, Department of Chemistry, Technical University of Munich, Munich

Theoretical insights into ultrafast dynamics of biological chromophores and fluorescent sensors in the gas phase and in solution

11.45-12.15

OC2

Leszek Łapiński, Institute of Physics, Polish Academy of Science, Warsaw

UV-induced hydrogen-atom transfer in phenol and thiophenol

12.15-12.35

OC3

Jadwiga Konarska, Faculty of Chemistry, Warsaw University, Warsaw

Ultrafast dynamics of intermolecular interaction in CCl4 probed by isotope effect visible in the stretching vibration

12.35-12.50

C1

Sebastian Szopa, SHIM-POL, Izabelin, Exhibitor presentation

Exhibitor presentation: New solutions in spectroscopic techniques

13.00-14.30 Lunch

Conference Program



Afternoon Session: 14.30-19.00

Charge transfer and structure

14.30-15.30

PL2

Andrzej Kapturkiewicz, Institute of Chemistry, Siedlce University of Natural Sciences,

Siedlce

Luminescence from 3*

MLCT states studied with combined Marcus-Jortner and Mulliken-Hush formalisms

15.30-16.00

OC4

Jerzy Karpiuk, Institute of Physics, Polish Academy of Science, Warsaw

Triplet state dynamics in donor-acceptor systems visualised by triple phosphorescence

16.00-16.30

OC5

Olaf Morawski, Institute of Physics, Polish Academy of Science, Warsaw

Environment-sensitive photophysics of a hyperpolarizable push-pull pyrazole derivative


17.00-17.45

IL2

Artur Sikorski, Faculty of Chemistry, University of Gdańsk, Gdańsk

From crystal engineering to new materials based on acridine dyes

17.45-18.15

OC6

Katarzyna Jarzembska, Czochralski Laboratory of Advanced Crystal Engineering,

Biological and Chemical Research Centre, Department of Chemistry

Direct observation of the excited state structure of a model Ag(I)-Cu(I) complex

19.00-20.30 Dinner


Evening Session: 20.30-21.30

Poster session

Wednesday, 30 September 2015


8.00-13.00

Excursion

13.00-14.30 Lunch



Old problems, new challenges

14.30-15.30

PL3

Peter Gilch, Institute of Physical Chemistry, Heinrich Heine University, Düsseldorf

Thioxanthone: A photophysical chimera deciphered?

15.30-16.00

OC7

Bolesław Kozankiewicz, Institute of Physics, Polish Academy of Science, Warsaw

On photo-oxidation of single aromatic molecules

16.00-16.30

OC8

Mateusz Gierszewski, Faculty of Chemistry, Adam Mickiewicz University, Poznań

5-Deazaalloxazine: transient absorption spectra

Conference Program



17.00-17.45

IL3

Yevgen Poronik, Institute of Organic Chemistry, Polish Academy of Sciences, Warsaw

Rational design of merocyanine chromophores - promising two-photon absorbers

17.45-18.15

OC9

Marek Sikorski, Faculty of Chemistry, Adam Mickiewicz University, Poznań

Photochemistry of alloxazines – past, present and …

18.15-18.45

OC10

Łukasz Orzeł, Faculty of Chemistry, Jagiellonian University, Kraków

Transmetalation of chlorophylls – molecular mechanisms and consequences for the ground and excited states of the pigment

18.45-19.00

C3

Józef Dresner, Eurotek International, Warsaw

Exhibitor presentation

19.00-20.30 Dinner

Thursday, 1 October 2015



Wonderful world of unusual matter and light

9.00-10.00

PL4

Jack Simons, Department of Chemistry, University of Utah, Salt Lake City

The wonderful world of molecular anions, electrons, and photons

10.00-10.45

IL4

Marcin Andrzejak, Faculty of Chemistry, Jagiellonian University, Kraków

Excited states of biheterocyclic compounds by single and multi-reference methods

10.45-11.05

OC11

Mercedes Kukułka, Faculty of Chemistry, Jagiellonian University, Kraków

Excited states of pyromellitic diimides - theoretical modelling of the absorption and MCD spectra


11.30-12.00

OC12

Wojciech Macyk, Faculty of Chemistry, Jagiellonian University, Kraków

Reduction of small molecules in photocatalytic systems

12.00-12.20

OC13

Marcin Kobielusz, Faculty of Chemistry, Jagiellonian University, Kraków

Spectroelectrochemical method of surface states characterization and DOS determination for semiconducting metal oxide electrodes

12.20-12.40

OC14

Szymon Wojtyła, Faculty of Chemistry, Jagiellonian University, Kraków

Photocatalytic activity of neat and dye sensitized CuI toward degradation of organic pollutants and inactivation of microorganisms

12.40-13.00

OC15

Michał Pacia, Faculty of Chemistry, Jagiellonian University, Kraków

Activation of hydrogen peroxide on TiO2

13.00-13.15

C3

Bogusław Burak, Comef Aparatura Naukowo-Badawcza, Katowice

Exhibitor presentation: Comef for IR, ViS and UV spectroscopy

13.15-14.30 Lunch

Conference Program




Panel discussion: Open questions and alternative approaches in modelling photodissociation dy-namics

15.00-16.30

Part 1

Jerzy Karpiuk, Institute of Physics, Polish Academy of Science, Warsaw

Introduction

Jack Simons, Department of Chemistry, University of Utah, Salt Lake City

How the wonderful world of molecular anions, electrons, and photons relates to π*-σ* couplings

Piotr Skurski, Faculty of Chemistry, University of Gdańsk, Gdańsk

Unanswered questions concerning the dipole-bound anions

Open discussion


17.00-18.30

Part 2

Mike Ashfold, School of Chemistry, University of Bristol, Bristol

The role of (n/π)σ* states in molecular photofragmentation processes and dissociative electron attachment processes

Tolga Karsili, Department of Chemistry, Technical University of Munich, Munich

Comparing the π-σ* state-driven photodissociation dynamics of neutral, cationic and anionic molecules

Open discussion


Evening, 20.00 – 24.00

Conference Dinner

Friday, 2 October 2015

Friday, 2 October 2015


Spectroscopic techniques and new materials

9.00-10.00

IL5

Małgorzata Barańska, Faculty of Chemistry, Jagiellonian University, Kraków

Raman spectroscopy of biological molecules: natural pigments and single cell studies

10.00-10.30

OC16

Daniel Friese, Centre for Theoretical and Computational Chemistry, University of Tromsø,

Tromsø

Multiphoton circular dichroism: Two- and three-photon chiroptical light absorption


11.00-11.30

OC17

Jerzy Langer, Faculty of Chemistry, Adam Mickiewicz University, Poznań

Are exciton-polaritons involved in non-linear emission of a polyaniline diode?

11.30-12.00

OC18

Radosław Kamiński, Czochralski Laboratory of Advanced Crystal Engineering, Bio-

logical and Chemical Research Centre, Department of Chemistry

New luminescent materials based on ortho-phenylenediboronic acid – from crystal engineering to spectroscopic properties

12.00-12.10 Closing remarks

12.30-13.30 Lunch

List of Posters


Posters:

P1 Iwona Anusiewicz, Faculty of Chemistry, University of Gdańsk, Gdańsk

High-symmetry compact structures are preferred equilibrium configurations of LinFn+1-

(n=2–5) superhalogen anions

P2 Joannna Cybińska, Katarzyna Komorowska, Department of Nanotechnology, Wrocław Research Centre EIT+, Wrocław

Luminescent materials based on lanthanide ions incorporated into silica-based matrixes

P3 Marcin Czapla, Faculty of Chemistry, University of Gdańsk, Gdańsk

Novel strong superacids HAlnF3n+1 (n=1-4)

P4 Sylwia Freza, Faculty of Chemistry, University of Gdańsk

Double amino acid – A novel molecule enabling peptide interpenetrating structures

P5 Małgorzata Insińska-Rak, Faculty of Chemistry, Adam Mickiewicz University, Poznań

Photochemical reactions of vitamin B2 and its derivatives

P6 Edyta Majsterek, Institute of Physics, Polish Academy of Sciences, Warsaw

Radiative and non-radiative deactivation of triarylmethane lactones and lactams in

1CT and

3CT states

P7 Dorota Prukała, Faculty of Chemistry, Adam Mickiewicz University, Poznań

Photophysical properties of alloxazine derivatives in dependence of pH

P8 Michał Rode, Institute of Physics, Polish Academy of Sciences, Warsaw

Ferroelectric molecular switching based on double proton transfer: dynamical simulations and ab initio calculations

P9 Celina Sikorska, Faculty of Chemistry, University of Gdańsk, Gdańsk

Utilizing fluoroxyl groups as ligands in superhalogen anions: an ab initio study of the M(OF)k+1

– systems (M=Li, Na, K, Be, Mg, Ca, B, Al)

P10 Piotr Skurski, Faculty of Chemistry, University of Gdańsk, Gdańsk

Antenna role of the (HAlF4)- dipole-bound anionic state in the superacid fragmentation process

P11 Marek Węcławski, Institute of Organic Chemistry, Polish Academy of Sciences, Warsaw

Planar, fluorescent push–pull system comprising benzofuran and iminocoumarin moieties

Plenary Lectures


Plenary Lectures

Opening Lecture


Nonlinear absorption of light by molecules and nanoobjects

Samoć M.

Advanced Materials Engineering and Modelling Group, Faculty of Chemistry,

Wrocław University of Technology, [email protected]

Although nonlinear absorption of light is a phenomenon that has been well known and wide-ly studied since the advent of lasers, its widespread applications have not emerged until mode-locked femtosecond Ti-sapphire and fibre lasers became available in the nineties. The studies carried out by my research team in Wrocław for the last few years have concentrated on char-acterizing and optimizing nonlinear absorption processes in structures of various types: organic and organometallic molecules as well as nanostructures that may be of interest for photonics, biophotonics and nanomedicine. The main aim was to obtain strong enough nonlinear optical (NLO) effects under excitation with short pulse lasers to enable diagnostic or therapeutic appli-cations. Among the nanostructures studied by us the focus was on colloidal nanoparticles of various chemical compositions and properties that may be tuned by changing their size and shape, nanostructures of biological origin as well as hybrid structures that may be engineered out of smaller building blocks.

To characterize nonlinear absorption in a proper way, it is necessary to obtain full spectra of the changes of the absorption coefficient as function of the light intensity. This calls for laborious wide wavelength range studies, performed with tunable femtosecond laser systems where ei-ther the changes of absorbance are measured directly, as in the technique of Z-scan (and, introduced by us recently, f-scan [1]) or the absorption processes involving more than a single photon are detected by appearance of upconverted emission. Our group has obtained nonlinear absorption spectra for numerous dyes, polymers, dendrimers as well as nanoparticles such as quantum dots [2] and rods [3], plasmonic structures (gold nanorods [4] and nanoshells [5]) and lanthanide-doped fluoride [6] and oxide [7] nanocrystals. The two-photon cross sections for molecules and various nanosized species, usually expressed in Goeppert-Mayer units (1GM=10

-50 cm

4s) may vary by many orders of magnitude, but it is interesting to find that most

of best nonlinear absorbers studied by us, both molecules and nanoparticles, have the peak

values of molecular mass-normalised cross sections 2/M on the order of 1 GM mol/g.

An exciting new field of research concerns nonlinear optical effects in biomolecules and nanostructures formed by them. Surprisingly, sizable nonlinear absorption exists in amyloid aggregates [8] and possibly also in other organic materials such as silk. Such aggregates also

show interesting optical properties when forming complexes with dyes [9] and -conjugated polymers [10].

[1] R. Kolkowski, M. Samoc, J. Opt., 16 (2014). [2] a) J. Szeremeta, M. Nyk, D. Wawrzynczyk, M. Samoc, Nanoscale, 5, 2388 (2013); b) M. Nyk, D. Wawrzynczyk, J. Szeremeta, M. Samoc, Appl. Phys. Lett., 100, 041102 (2012). [3] M. Nyk, J. Szeremeta, D. Wawrzynczyk, M. Samoc, J. Phys. Chem. C 118, 17914 (2014). [4] J. Olesiak-Banska, M. Gordel, R. Kolkowski, K. Matczyszyn, M. Samoc, J. Phys. Chem. C 116, 13731 (2012). [5] M. Gordel, J. Olesiak-Banska, R. Kolkowski, K. Matczyszyn, M. Buckle, M. Samoc, J. Mat. Chem. C, 2, 7239 (2014). [6] M. Nyk, D. Wawrzynczyk, K. Parjaszewski, M. Samoc, J. Phys. Chem. C, 115, 16849 (2011).

[7] D. Wawrzynczyk, M. Nyk, M. Samoc, J. Mat. Chem. C, 1, 5837 (2013). [8] P. Hanczyc, M. Samoc, B. Norden, Nature Photonics, 7, 969 (2013). [9] L. Sznitko, P. Hanczyc, J. Mysliwiec, M. Samoc, Appl. Phys. Lett. 106, 023702 (2015). [10] P. Hanczyc, A. Justyniarski, D. Gedefaw, M. Andersson, M. Samoć, C. Muller, RSC Advances, 66, 49363 (2015).

Plenary Lectures


Molecular photofragmentation dynamics in the gas and condensed

phases: similarities and differences.

Ashfold M.N.R.

School of Chemistry, University of Bristol, Bristol, U.K., BS8 1TS

The interaction of light with molecules underpins many of the positives of everyday life (e.g. photosynthesis, vision, etc) but can also be detrimental (e.g. DNA damage, photolesions, etc). What factors determine molecular photostability, or the likelihood of photodamage? Phenols and azoles are common chromophores in the nucleobases and aromatic amino-acids that do-

minate the near-UV absorption spectra of many biological molecules. * excitations are responsible for these strong UV absorptions, but these molecules also possess excited states

formed from * electron promotions. These * excited states generally have much smaller absorption cross-sections, but their photochemical importance is becoming ever more widely recognized.[1] We have used photofragment translational spectroscopy (PTS) methods and

complementary ab initio theory to explore *-state mediated bond fission processes following

UV excitation of many heteroaromatic molecules in the gas phase, and ultrafast pump-probe studies to explore the same (and related) processes in solution. This presentation will (i) summarize the state of knowledge derived from PTS studies of phenol and related molecules in the gas phase,[2] (ii) highlight the extent to which such knowledge can inform our interpretation of ultrafast pump-probe studies of the UV photofragmentation of similar molecules ((thio)phenols, ethers, etc) in solution [3-5] and (iii) demonstrate how such solution

phase studies offer a route to exploring *-state mediated ring opening of heterocyclic molecu-les (furans, thiophenes, etc). [6]

Acknowledgments: Funding from EPSRC (Programme Grants EP/G00224X and EP/L005913)

is gratefully acknowledged. [1] See, e.g., M.N.R. Ashfold, et al., Phys. Chem. Chem. Phys. 12, 1218 (2010). [2] T.N.V. Karsili, et al., Chem. Sci. 4, 2434 (2013). [3] Y. Zhang, et al., Farad. Disc. Chem. Soc. 157, 141 (2012). [4] S.J. Harris, et al., Phys. Chem. Chem. Phys. 15, 6567 (2013). [5] S.J. Harris, et al., J. Phys. Chem. A 118, 10240 (2014). [6] D. Murdock, et al., Phys. Chem. Chem. Phys. 16, 21271 (2014).

Plenary Lectures


Luminescence from 3*MLCT states studied with combined Marcus-

Jortner and Mulliken-Hush formalisms

Kapturkiewicz Andrzej

Institute of Chemistry, Faculty of Sciences, Siedlce University of Natural Sciences and Humanities, 3 Maja 54, 08-110 Siedlce, Poland, [email protected]

According to the Mulliken-Hush approach a close relationship between the termal, non-

radiative and optical, radiative electron transfer processes is crucial for the properties of the excited inter-molecular as well as of the intra-molecular charge transfer states. A close relation-

ship between these processes is given by the Mulliken-Hush expression M = V/E where the transition dipole moment for the optical electron transfer, M, is related to the electronic coupling

matrix element for the thermal electron transfer, V, via the change in dipole moment associ-

ated with the electron transfer and the energy gap E between the states involved in these

processes. The Mulliken-Hush expression (together with the Born-Oppenheimer approximation and the Franck-Condon principle) allows unified description of rates of the radiative electron transfer (exemplified by the charge transfer absorption and emission) and the non-radiative charge recombination (repopulation of the ground state by means of the internal conversion). Careful use of

1*CT absorption and/or emission band analysis may provide additional intrinsic

information about the investigated systems. In particular, if the excited 1*CT state deactivates

only (with the lack of any intersystem crossing processes) due to the radiative and the non-

radiative 1*CT S0 transition, the quantities available from the band shape analysis have be

succesfuly used for the interpretation of the non-radiative rate constants knr for the “pure” or-

ganic inter-molecular as well as intra-molecular electron transfer systems.

Similarly as in the case of organic inter-molecular and intramolecular electron transfer sys-tems the radiative and nonradiative excited state decays of the transition metal complexes ex-hibiting metal-to-ligand charge-transfer (MLCT) phenomena can be deliberated in an analogous way. However, this is a somewhat more complicated task as compared to ‘‘pure’’ organic sys-tems because in the electron transfer systems involving heavy metals additional effects (e.g. spin-orbit coupling) can play a crucial role. Our recent investigations illustrate that, similar to

electron transfer in organic inter-molecular as well intra-molecular systems, 3*MLCT S0 tran-

sitions can be successfully examined with a relatively simple and intuitive approach, especially useful when comparative studies of the transition metal complexes with analogous molecular and similar electronic structures are undertaken. By modifying the ligand(s) in the coordination sphere of the given transition metal ions one can monotonically tune their phosphorescent emission properties that make consistent analysis of the experimentally achieved data much easier. This will be presented for series of the heteroleptic osmium(II) and rhenium(I) complexes

with -diimine ligands N∩N. The observed differences in kinetics of radiative and non-radiative

deactivation of the excited 3*MLCT states have been found markedly dependent on the nature

of the diimine N∩N electron acceptor that allowed us for a more detailed discussion. The most

important conclusion from our works is the crucial role of the lowest excited 3*LC state and its

interactions with the excited 3*MLCT state. Such interactions lead to different energy splitting

between the excited 3*MLCT and

1*MLCT states influencing additionally the spin-orbit coupling

between them. Consequently, it leads to well pronounced differences in kinetics of the radiative

and non-radiative 3*MLCT S0 transitions. The observed differences can be quantitatively de-

scribed using the combined Marcus-Jortner and Mulliken-Hush formalisms.

[1] A. Kamecka, A. Kapturkiewicz, Phys.Chem.Chem.Phys. (in press) DOI: 10.1039/C5CP03299G

[2] A. Woźna, A. Kapturkiewicz, Phys.Chem.Chem.Phys. (submitted)

Plenary Lectures


Fig.1 Femtosecond UV/Vis absorption on TX in cyclohexane.

Black arrows mark positions where spectral changes due to IC

and ISC processes are particulariyl pronounced.

Thioxanthone: A Photophysical Chimera Deciphered?

Villnow T.

1, Mundt R., Gilch P.

1

1 Institut für Physikalische Chemie, HHU Düsseldorf, [email protected]

Textbooks on organic photochemistry commonly reserve many pages for aromatic carbonyls

(see e.g. ref. [1]). Name reactions in photochemistry like Norrish type I & II or Paterno-Büchi involve such compounds. To a great extent their rich photochem-istry is related to efficient intersys-tem crossing (ISC) populating triplet states. By scrutinizing thi-oxanthone (TX) – a prototypical aromatic carbonyl we seek a profound understanding of ISC in these compounds [2,3]. The pho-tophysical properties of TX are strongly solvent dependent. For instance, its fluorescence quan-tum yield in cyclohexane is ~ 10

-4

whereas it is close to unity in water. This effect can be attrib-uted to solvent shifts of the ex-cited states involved in ISC [4].

With femtosecond UV/Vis ab-sorption and fluorescence spectroscopy we studied ISC of TX in various solvents. Assignment of spectral signatures and rate constants was backed by high level quantum chemistry [3]. In this presentation we will focus on TX in cyclohexane and methanol. In cyclohexane (see Fig. 1) the primary

1ππ

* excitation decays very rapidly (~ 400 fs) via internal conversion (IC) to a

1nπ

*

state. The ensueing ISC process takes ~ 4 ps and yields the lowest triplet state of 3ππ

* charac-

ter. In methanol and for excitation condition providing little excess energy the 1nπ

* state is not

accessible [2]. Therefore, the initial process is an ISC process populating a 3nπ

* state within 5

ps. “Accidentally”, this state is isoenergetic with the primary 1ππ

* excitation resulting in a chi-

meric behaviour. TX simultaneously features properties of singlet and triplet excitations. A slow (~ 2.5 ns) IC process ensues - yielding the

3ππ

* state. Exciting TX in methanol with higher ex-

cess energy, that is employing shorter wavelengths, renders the 1nπ

* state accessible. To some

part the 3ππ

* state is now accessed via the faster pathway seen for TX in cyclohexane.

[1] N.J. Turro, V. Ramamurthy, J.C. Scaiano, Modern Molecular Photochemistry of Organic Molecules

(University Science Books, Sausalito, 2010)

[2] T. Villnow et al., J. Phys. Chem. A. 118, 11696 (2014)

[3] V. Rai-Constapel et al., J. Phys. Chem. A. 118, 11708 (2014)

[4] V. Rai-Constapel et al. J. Phys. Chem. A. 115, 8589 (2011)

Plenary Lectures


Fig.1 Figure caption

The wonderful world of molecular anions, electrons, and photons

Jack Simons

1

1Department of Chemistry, University of Utah, [email protected]

This presentation will focus on several phenomena that arise when an electron binds to a neutral molecule to form an anion and a photon acts on the anion to induce a chemical or physical change. There are significant differences between the behavior of anions and neutral molecules resulting from differences in their internal Coulomb potentials. The first part of this

presentation will illustrate the important roles such Coulomb potentials have in altering the photoelectron spectra of multi-ply charged anions. Next, the subject of how low-energy electrons attach to DNA and induce cancer-causing strand breaks will be discussed. Finally, the use of photo-induced electron transfer into thymine-dimer damaged DNA to bring about dam-age repair will be explained. In all of these examples, the timescales within which electrons, molecular geometries, and sol-vent polarizations respond are important to keep in mind.

[1] J. Simons, Acc. Chem. Res. 39, 722 (2006)

[2] I. Sieradzan, M. Marchaj, I. Anusiewicz, P. Skurski, J. Simons, J. Phys. Chem. A 118, 7194 (2014)

[3] J. Simons, J, Phys. Chem. A 112, 6401 (2008)

Invited Lectures


Invited Lectures

Invited Lectures


Theoretical Insights into Ultrafast Dynamics of Biological

Chromophores and Fluorescent Sensors in the Gas Phase and in Solution

Karsili T. N. V.

Department of Chemistry, Technical University of Munich, Munich, Germany.

Email: [email protected]

The way in which the solvent and cluster environment affects the photophysics and photo-chemistry of isolated organic and biological chromophores has been the focus of many ultrafast pump-probe experiments in solution. Biological chromophores – like adenine (for example) – are known to undergo photodegradation at elevated photon energies, but their prevailing excit-ed state decay mechanisms ensure photostability – i.e. they undergo ultrafast internal conver-sion via well-characterised intrinsic molecular distortions that lead to state degeneracies along the excited state potential energy surface – without detriment to the starting molecule.

In a water cluster or in bulk water solution, the additional complexities of hydrogen-bonds af-fect the non-radiative decay pathways available to molecules such as phenol and adenine. Intrinsic excited state solute → solvent or solvent → solute hydrogen transfers provide new channels by which the excited state molecule can decay.

The ‘power’ of hydrogen bonding will be illustrated by theoretical data showing how excited state intramolecular hydrogen transfer in biological sunscreens found on the human skin and in the eye can afford natural photostability. Such systems will then be extended to bulk solution in which excited state deactivations are encouraged via solute-solvent/cluster intermolecular hy-drogen transfer reactions. This part of the talk will focus on the excited state reactivity of the solute aromatic chromophore (e.g. phenol and adenine) with water clusters and water ‘wires’ both in the gas phase and in bulk water solution. The final part of the talk will focus on extrapo-lating the lessons learnt from the photochemistry of model aromatic systems to somewhat larger and biologically/industrially applied systems. In this part photoinduced proton-coupled electron transfer reactions drive the photochemical outcomes in fluorescent sensors used in, for exam-ple, DNA biodiagnostics, LOGIC gates and water supply systems.

Invited Lectures


Fig.1 Crystal structure of a new acriflavine-based material

From crystal engineering to new materials based on acridine dyes

Sikorski Artur

Faculty of Chemistry, University of Gdańsk, W. Stwosza 63, 80-809 Gdańsk, Poland

e-mail: [email protected]

Acridine dyes have occupied a special place in many fields of research. This is due not only to their staining and fluorescence properties, which are commonly applied in studies of various

physicochemical and biological systems. Acridines are interesting objects of research due to the fact that they represent active phar-maceutical ingredients (APIs). This group of compounds, espe-cially aminoacridines, exhibits a wide spectrum of biological activi-ties, such as: antiamoebic, anti-bacterial, antiprion, antitumor, anti-inflammatory, antihyperten-sive, antiviral, and much more. One of the major challenges of modern medicine is the search for new forms of drugs. This is due the fact that many of the currently used drugs have a limited bioa-vailability due to the poor solubili-

ty in the water. Crystal engineering offers an indirect solution to this problem. One of its tasks is the synthesis of multicomponent crystalline systems (co-crystals, salts and/or their solvates) in which one component represents an active pharmaceutical ingredient (including API difficult to crystallize separately). In the context of applications in pharmacy, such systems not only exhibit a higher bioavailability, but they also tend to be more stable and the purification process is often less time consuming than in the case of other forms of drugs. The formation of such systems is directly associated with the possible interactions between the different components of crystal. For these reasons, much attention has been given to the crystallographic studies of interactions between acridine dyes and different kind of molecules and ions, e.g., carboxylic acids, halide ions and surfactants. In this lecture, the synthesis and structural characterization of new crystal-line materials based on acridine dyes will be presented.

This study was financed from the State Funds for Scientific Research through the National Science Centre (NCN) in Poland, Grant No. 2011/01/D/ST4/04943 (Contract No. UMO-2011/01/D/ST4/04943).

[1] P. Meisel, T. Kocher, J. Photochem. Photobiol. B 159 (2005)

[2] V. Chashchikhin, E. Rykova, A. Bagaturyants, Phys. Chem. Chem. Phys. 13, 1440 (2011)

[3] A.D. Price, D.K. Schwartz, J. Am. Chem. Soc. 130, 8188 (2008)

[4] S.M. Sondhi, J. Singh, R. Rani, P.P. Gupta, S.K. Agrawal, A.K. Saxena, Eur. J. Med. Chem. 45, 555

(2010)

[5] A. Sokal, E. Pindelska, Biul. Wydz. Farm. WUM 5, 37 (2013)

[6] A. Sikorski, D. Trzybiński, Tetrahedron Lett. 14, 2253 (2014)

[7] K. Kowalska, D. Trzybiński, A. Sikorski, CrystEngComm 17 (2015) DOI: 10.1039/C5CE01321F

[8] D. Braga, F. Grepioni, Making Crystals by Design: Methods, Techniques and Applications (Wiley-

VCH, Weinheim, 2007)

[9] G.R. Desiraju, J. Chem. Sci. 122, 667 (2010)

Invited Lectures


Rational design of merocyanine chromophores - promising two-

photon absorbers

Poronik Y.

Institute of Organic Chemistry, Polish Academy of Sciences, [email protected]

Design of novel chromophores possessing nonlinear optical (NLO) properties such as two-photon absorption (TPA) has been attracting considerable attention in recent years owing to the prospect of using them in a wide range of applications including two-photon excited fluores-cence (TPEF) microscopy for visualization of extra- and intracellular environment, optical limit-ing, 3D microfabrication etc.

From the structural point of view, the majority of 2PA chromophores belong to the family of push-pull polyenes with electron donor and acceptor at the edges of the conjugated system. Merocyanine dyes are similar to polyenes, have electrically neutral chromophore, but in contrast to the latter they are characterized by more efficient intramolecular charge transfer (ICT) be-tween electron-donor and electron-withdrawing groups, which potentially results in higher two-photon cross-section at the shorter conjugated chain.

Different structural and synthetic approaches were employed to design efficient TPA mero-cyanine chromophores.

[1] Y. M. Poronik, V. Hugues, M. Blanchard-Desce, D. T. Gryko, Chem. Eur. J. 18, 9258 (2012)

[2] Y. M. Poronik, G. Clermont, M. Blanchard-Desce, D. T. Gryko, J. Org. Chem. 78, 11721 (2013)

[3] Y. M. Poronik, D. T. Gryko, Chem. Commun. 50, 5688 (2014)

[4] M. Tasior, Y. M. Poronik, O. Vakuliuk, B. Sadowski, M. Karczewski, D. T. Gryko, J. Org. Chem. 79,

8723 (2014)

Invited Lectures


Excited states of biheterocyclic compounds by single and multi-

reference methods

Andrzejak M.

Faculty of Chemistry, Jagiellonian University, [email protected]

Biheterocyclic compounds display markedly different properties, a s compared to their single-ring counterparts, so that they should be regarded as the simplest members of the re-spective oligomeric series. Being relatively small, they can be theoretically studied by a wide spectrum of methods. On the one hand, this provides a way of obtaining credible results that can possibly be extrapolated to higher oligomers. On the other hand, the biheterocycles can serve as model systems that enable calibration of less computationally demanding approaches, which can be subsequently used for larger systems. Finally, the biheterocyclic compounds themselves reveal unexpected and interesting challenges for theoretical modeling.

The presentation will be mostly devoted to the problems that may arise if more than just the lowest excited state is addressed theoretically. At the example of the trans-2,2’-bithiophene the optically allowed (Bu) and symmetry forbidden (Ag) singlet states will be dis-

cussed in terms of the time dependent version of DFT, various Coupled Cluster models, as well as the multi-reference methods (MR-CI and CASSCF/CASPT2 approach). The basis set de-pendence of the excitation energies will be analyzed. Unexpectedly erratic behavior of some of the low-energy roots will be demonstrated and rationalized in terms of Rydberg states interfer-ence, caused by insufficient flexibility of standard basis sets to describe orbitals of large spatial extent. Eventually, the performance of theoretical methods as tools for geometry modeling and characterization of excited triplet states will be briefly discussed.

Invited Lectures


Raman spectroscopy of biological molecules: natural pigments

and single cells studies

Majzner K., Szafraniec E., Zajac G., Pacia M., Kaczor A., Baranska M.

Faculty of Chemistry, Jagiellonian University, [email protected] & Jagiellonian Center of Experimental Therapeutics, Jagiellonian University

The paper shows a potential of Raman spectroscopy for analysis of various biological sys-

tems. First, an application of Confocal Raman imaging to monitor a cellular composition as a result of anthracycline exposure on living endothelial cells is discussed.

Chemotherapeutic anthracycline antibiotics such as doxorubicin (DOX), daunorubicin (DNR), epidoxorubicin (EDOX) and epidaunorubicin (EDNRA) are antibiotics of wide cytostatic effect. Their therapeutic range and effectiveness are high. Anthracyclines are a group of antibi-otics used as anti-tumor therapy include malignant lymphoma, acute leukemia, breast cancer, etc. Their function is related to formation a stable complex between the anthracycline and DNA helix, which prevents further division and leads to cell death. Anthracyclines, show a strong cardiotoxicity and induce apoptosis of the endothelial cells. In this study the influence of se-lected common anthracycline antibiotics on endothelial cells was compared. Obtained prelimi-nary results on the effects of anthracyclines on endothelial cells show a diverse accumulation of drugs (DOX, DNR) in the nucleus. The substantial changes in the cell nucleus are caused by the action of the anthracycline. Raman spectra of anthracycline standards show a fluorescence background in the high wavenumber range. This phenomena is also observed in the Raman spectra of anthracycline-stimulated cells, thus fluorescence of anthracyclines appears to be a good marker of the presence of anthracyclines in the cells.

In the second part, a stereochemistry of natural pigment and its aggregates is reported. Astaxanthin (3,3'-dihydroxy-ß-carotene-4,4'-dione) is a red xanthophyll pigment used in diet of salmonids and crustaceans. Due to its strong antioxidant activity it is used also as a dietary supplement, that prevents cardiovascular, immune, inflammatory, and neurodegenerative dis-eases. Racemic mixture of synthetic astaxanthin consists of 3S,3’S, 3R,3’R enantiomers and meso form in the 1:1:2 ratio. Pre-resonance ROA spectra for the six most stable astaxanthin conformers were calculated, and it has been found that some of the conformers exhibit opposite band signs than the other ones. Averaged ROA spectra could exhibit bands of both signs or could be monosignet, which depends on selected DFT functional, and energetic contribution of conformers. Carotenoids dissolved in organic-water media can form two types of aggregates: H (card-packed) and J (head-to-tail) that exhibit hypsochromic and batochromic shift of chromo-phore absorption, respectively. This work reports first experimental observation of resonance ROA (RROA) effect from chiral, supramolecular carotenoid assemblies of both astaxanthin enantiomers, obtained from various acetone-water solutions.

Carotenoids are pigments produced by many yeast species, responsible for defense against free radicals. Rhodotorula mucilaginosa (R. m.) is one of many yeast species capable of caro-tenoids de novo synthesis. Beside carotenoids, haemoglobin can be found in R. m. Moreover, “Raman signature of life”, a band at 1602 cm

-1, was observed as is a unique spectroscopic

feature directly related to mitochondria activity. The life band signal is related to heme functions although a direct link between them is unknown.

Acknowledgments

This work was supported by National Science Center (grant no. (DEC-2012/07/B/ST5/00889). The authors thank for the computing time to the Academic Computer Centre CYFRONET AGH, Krakow, Poland. This research was supported by PL-Grid Infrastruc-ture.

mailto:[email protected]

Panel Discussion


Panel Discussion

Open questions and alternative approaches in modelling

photodissociation dynamics

Panel Discussion


How the wonderful world of molecular anions, electrons,

and photons relates to *-* couplings

Jack Simons1

1Department of Chemistry, University of Utah, [email protected]

The electron-induced DNA damage [1,2] and the photon-activated electron-transfer thymine dimer repair [3] processes discussed in my presentation offer interesting examples of so-called

*-* state interactions. Two pioneers in the study of such conical intersections, the dynamics taking place near them, and their spectroscopic signatures, A. I. Sobolewski [4] and W. Domcke [5], are well known to this audience. I will attempt to offer my insight into differences between the two cases I have discussed and those that occur in gas-phase neutral molecules that are likely more familiar to participants at this conference. I will also be happy to share what I know about dipole-bound anion states because they have been attracting more interest from the photo-chemistry and photo-physics communities lately.

A. I. Sobolewski W. Domcke

[1] J. Simons, Acc. Chem. Res. 39, 722 (2006)

[2] I. Sieradzan, M. Marchaj, I. Anusiewicz, P. Skurski, J. Simons, J. Phys. Chem. A 118, 7194 (2014)

[3] J. Simons, J, Phys. Chem. A 112, 6401 (2008)

[4] http://www.ifpan.edu.pl/ON-2/on21/sobola.html

[5] http://www.theo.ch.tum.de/index.php?id=625&L=1

http://www.ifpan.edu.pl/ON-2/on21/sobola.html

http://www.theo.ch.tum.de/index.php?id=625&L=1

Panel Discussion


Unanswered questions concerning the dipole-bound anions

P. Skurski

Department of Chemistry, University of Gdańsk, [email protected]

The large body of work on dipole-bound anionic states has been established during past two

decades, employing state-of-the-art theoretical ab initio methods and advanced spectroscopic techniques. Despite revealing the electronic structure of many molecular anions of dipole-bound nature and identifying the interactions responsible for an excess electron binding in such species, certain important issues were left unaddressed. The remaining unanswered questions include the binding of two (or more) excess electrons by the dipole potential, the roles of electrostatics in forming dipole-bound anions, and the real nature of such objects.

How to explain the fact that the critical dipole moment required for binding of two electrons was found identical as that for one electron (in the fixed (non-rotating) finite dipole limit)? Why does the electrostatic contribution to the excess electron binding energy vanish for certain polar molecules (recognized as typical parent neutral host capable of forming dipole-bound anions)? These and other problems associated with the anions bound by the dipole potential will be presented and the discussion on these issues will be ignited.

Fig. 1 The difference in an excess electron distribution between a representative valence-bound state (upper left) and dipole-bound state (lower right) of the HAlO

– anion.

Panel Discussion


The role of (n/)* states in molecular photofragmentation and dissociative electron attachment processes

Ashfold M.N.R.

School of Chemistry, University of Bristol, Bristol, U.K., BS8 1TS

A simple approach to thinking how photon absorption induces bond fission within a molecule might picture the bond of interest as an effective ‘chromophore’, and assume that the photoexci-

tation removes (bonding) and/or creates * (antibonding) density between the relevant atoms. In this contribution, we explore how well such a simple picture can account for the observed photofragmentation dynamics that arise following (vacuum) ultraviolet photoexcitation of many families of hydride molecules – water, hydrogen sulfide and related alcohols and thiols, ammo-nia and amines and simple nitrogen containing heterocycles, methane, ethyne and hydrogen cyanide – and the extent to which it can be extrapolated further to account for the dynamics of dissociative electron attachment ppocesses.

Acknowledgments: Funding from EPSRC (Programme Grants EP/G00224X and EP/L005913)

is gratefully acknowledged. [1] See, e.g., M.N.R. Ashfold, et al., Phys. Chem. Chem. Phys. 12, 1218 (2010).

Panel Discussion


Comparing the * state-driven photodissociation dynamics of neutral, cationic and anionic molecules

Karsili T. N. V.

Department of Chemistry, Technical University of Munich, Munich, Germany.

Email: [email protected]

The photodissociation dynamics of small neutral molecules such as water, hydrogen sul-phide and ammonia has attracted vast attention since the early 80s. It is well known that the

dissociation of such small molecules are facilitated by n states which absorb in the deep-UV

(typically < 220 nm) – leading to scission of the bond along which the orbital is localised. Following photodissociation of such small molecules, the distribution of internal energy in the nascent fragments can be understood by considering the initially excited (ro)vibronic level of the parent molecule and the various non-adiabatic transitions between electronic potential energy surfaces (PES) en route to dissociation.

Lessons learnt from such small neutral molecules can then extrapolated to medium sized heteroaromatic and functionalized aromatic molecules (such as phenol, pyrrole and indole) in a ‘bottom-up type’ approach in order to ascertain the similarities and differences between such

medium sized to smaller sized molecules. In these aromatic chromophores, the presence of

electrons introduce bound low-lying * and dissociative * states – the latter of which leads to

dissociation of the bond along which the * orbital is localized. The photodissociation dynamics of such medium sized molecules are now also well understood both experimentally and theoret-ically.

The logical next step is to extend such a bottom-up approach to charged molecules. Using high-level electronic structure theory, we show how the profiles of the PES topography varies upon the addition of a single electron to form the open-shell anionic species. We reveal the

presence low-lying dipole-bound states which couple onto dissociative 2* states. A systematic

pattern is observed when the small molecular anions (e.g. water– and ammonia

–) are extended

to somewhat larger molecular anions (such as phenol–

and pyrrole–). We compare our results

not only to the neutral analogues but also to known cationic species.

Panel Discussion


Oral Communications


Oral Communications

Oral Communications


S0(X)S0 (Z)

S1’(*)

CI

1 2

S1’

frame

crane

Y

HX Z

YH

X Z X

YH

Z

Y

HZX

YH

X Zframe

crane

Y

HX Z

YH

X Z

YH

YH

X Z X

YH

ZXX

YH YH

Z

Y

HZX

YH

X Z

Y

HZX

YH

X Z

YH

X Z

molecular

frame

proton

crane

Fig.1 TWIST-assisted mechanism of molecular switching (TPT)

ESIPT-based mechanisms of molecular photoswicthing

Rode M. F.

1, Jankowska J.

2

1 Institute of Physics, Polish Academy of Sciences, [email protected]

2 College of Inter-Faculty Individual Studies in Mathematics and Natural Sciences,

University of Warsaw

Molecular switches which enable the storage of information on a molecular level may have application in nanotechnology, biomedicine, and computer chip design. The molecular system

which can serve as a molecular switch must posses two stable forms which may be switched by an electric field, chemical reaction or by an optical excitation. In our investigation we are searching for molecular photo-switches which operate on the Excited State Intramolecular Proton Transfer (ESIPT) phe-nomenon (see Fig. 1) [1-8]. The switching process induced by an optical excitation involves the long-distance transfer of a proton between the two remote proton-donnating/accepting sites: “X”

and “Z” both located within the “molecular frame” unit (F). In this communication the photoswitching mechanisms based on Twist-assisted ESIPT pro-cess (TPT) is presented [1-6]. The TPT mechanism is mediated by the “proton crane” functional unit. The mechanism of the TPT class of photoswitches will be exemplified by the study of photophysics of two isolated model molecules: 7-hydroxy-8-carbaldehyde-quinoline [1-3] and salicylidene-methylamine (SA) [4-6]. Photodynamic simulations performed for the SA molecule in its excited and the ground-electronic state, have estimated time-scale of the switching pro-cess [6]. Our study shows that the energetical landscape of the ground and the lowest excited states can effectively be modulated by chemical substitutions to the parental molecules [3,8]. [1] A. L. Sobolewski, Phys. Chem. Chem. Phys. 10, 1243 (2008) [2] L. Lapinski, M. J. Nowak, J. Nowacki, M. F. Rode and A. L. Sobolewski, ChemPhysChem 10, 2290 (2009) [3] M. F. Rode and A. L. Sobolewski, J. Phys. Chem. A 114, 11879 (2010) [4] J. Jankowska, M. F. Rode, J. Sadlej, and A. L. Sobolewski, ChemPhysChem 13, 4287 (2012) [5] J. Jankowska, M. F. Rode, J. Sadlej, and A. L. Sobolewski, ChemPhysChem 15, 1643 ( 2014) [6] L. Spörkel, J. Jankowska, and W. Thiel, J. Phys, Chem. B 119, 2702 (2015) [7] M. F. Rode and A. L. Sobolewski, Chem. Phys. 409, 41 (2012)

[8] M. F. Rode and A. L. Sobolewski, J. Chem. Phys. 140, 084301 (2014)


Oral Communications


SH

S

H

H

S

HH

S

b

OH

O

HH

O

b

phenol phenoxyl 25

h

. + H.

thiophenol thiyl 24 25

h h

. + H.

UV-induced hydrogen-atom transfer in phenol and thiophenol

Lapinski L.

1, Reva I.

2, Guliano B.M.,

2 Nowak M.J.,

1 Fausto R.

2

1 Institute of Physics, Polish Academy of Sciences, Warsaw, Poland; [email protected]

2 CQC, Department of Chemistry, University of Coimbra, Coimbra, Portugal

UV-induced hydrogen-atom-detachment and hydrogen-atom-transfer reactions were ob-served for phenol [1] and thiophenol [2] molecules isolated in low-temperature Ar matrices. For both compounds, the initial photochemical act was the detachment of hydrogen atom from the exocyclic O-H or S-H groups (Scheme 1). Excitation of matrix-isolated phenol with narrowband

UV ( = 275 nm) light resulted in appearance of two photoproducts: the phenoxyl radical and cyclohexa-2,5-diene-1-one. Narrowband irradiation of monomeric thiophenol at 285 nm led to generation of two thione tautomers of the compound: cyclohexa-2,4-diene-1-thione and cyclo-hexa-2,5-diene-1-thione. The infrared spectral signature of photogenerated thyil radical was also detected. The hydrogen-atom-transfer reactions observed for phenol and thiophenol were photoreversible. The observed phototransformations were interpreted in terms of processes

governed by repulsive * or n* states. [3]

Scheme 1. UV-induced hydrogen-atom-detachment and hydrogen-atom-transfer reactions observed for phenol and thiophenol isolated in Ar matrices. 24 = cycloxeha-2,4-diene-1-thione; 25 = cycloxeha-2,5-diene-1-one (top) or 25 = cycloxeha-2,5-diene-1-thione (bottom).

[1] B.M. Guliano, I. Reva, L. Lapinski, R. Fausto, J. Chem. Phys. 136, 024505 (2012)

[2] I. Reva, M.J. Nowak, L. Lapinski, R. Fausto, Phys. Chem. Chem. Phys. 17, 4888 (2015)

[3] A.L. Sobolewski, W. Domcke, C. Dedonder-Lardeux, C. Jouvet, Phys. Chem. Chem. Phys. 4, 1093

(2002)

Oral Communications


Fig.1 Figure caption

Ultrafast dynamics of intermolecular interaction in CCl4 probed by

isotope effect visible in the stretching vibration.

Konarska J.1, Polok K.

1, Ratajska-Gadomska B.

1, Pudłowski G.

1, and Gadomski W.

1

1 Faculty of Chemistry, University of Warsaw, [email protected]

Due to the existence of CCl4 isotopomers with varying amount of two chlorine isotopes the

Raman band, v1, of the isotropic stretching vibration of the frequency 460 cm

-1, is split into 5

peaks. The most interesting is the ratio of the relative intensities of particular peaks. It appears that the relative intensities observed in v

1 band of the stationary Raman spectrum of liquid CCl4

slightly differ from the expected probability ratios due to the natural abundance of conformers Cl

35 75,28% and Cl

37 24,22%. This fact has already been investigated [1,2,3] but not convinc-

ingly explained. We propose the model describing it as due to very weak interactions between molecules vibrating with close frequencies. Moreover, till now there is no proper investigation of the dynamics of the intermolecular interactions in liquid CCl4.

To look closer into this dynamics we performed the femtosecond nonreso-nant pump–probe experiments for pure liquid CCl4 and for mixtures of CCl4 and CHCl3 at different concentra-tions. In time domain signal, the vibra-tions of coherently excited molecules are visible. Spectra obtained with Fast Fourier Transform show the relative intensities of v

1 band components,

which are completely different than in stationary Raman spectrum [1]. Any-way, the direction of the change is in agreement with the predictions of our theoretical model as due to intermo-lecular interactions, which become apparent in the ultrashort time scale. From our experimental results we are able to withdraw the time evolution of

these interactions. To support our femtosecond measurements we have recorded Raman spectra of CCl4 mixed with CHCl3 and there is a visible change of relative intensities of components of v

1 band with the

mixture composition. For growing molar fraction of CHCl3 there is a monotonic intensity de-crease of a peak related to molecules with more Cl

35 atoms and increase of a peak correspond-

ing to heavier isotopomers. The result proves the presence of interactions between CCl4 mole-cules that become weaker upon dilution.

[1] Griffithis, J. E.; Pao, Y.-H. J.Chem.Phys. 46, 1679–1684 (1967) “Performance of a New Photoelec-tric Detection Method for Optical Spectroscopy. II. Application to Laser Raman Spectroscopy” [2] Chakraborty, T.; Rai, S. N. Spectrochim. Acta - Part A Mol. Biomol. Spectrosc. 62, 438–445 (2005) “Depolarization Ratio and Correlation between the Relative Intensity Data and the Abundance Ratio of Various Isotopes of Liquid Carbon Tetrachloride at Room Temperature”

Oral Communications


Triplet state dynamics in donor-acceptor systems visualised by

triple phosphorescence

Karpiuk J.1, Majka A.

2,


2 Institute of Physical Chemistry, Polish Academy of Science

Ultrafast (~150 fs) electron transfer following photoexcitation of tri- or diarylmethane lactones produces quantitatively a highly polar (μe ~25 D) covalently bound radical ion pair in singlet state,

1[D

•+–A

•–] [1-3]. Using time resolved luminescence spectroscopy we find that, apart from

the radiative decay, 1[D

•+–A

•–] relaxes via intersystem crossing to populate a short-lived (≤ 1 ms)

triplet radical ion pair, 3[D

•+–A

•–], which subsequently recombines to yield two other emitting

triplets: a long-lived (2.4 s) donor-centered triplet state, [3D*–A], and a shorter-lived (~50 ms)

triplet biradical, 3[D–A

••]*. The 77 K luminescence spectrum in organic solvent glasses compris-

es one fluorescence and three phosphorescence bands, and shows a large red shift with in-creasing medium polarity. The glasschromic effect reflects a glass polarity-dependent ratio of phosphorescence band intensities, which in turn results from a medium-mediated decay of the triplet RIP and the partitioning of the return electron transfer into the non-dissociative and disso-ciative routes leading to two other triplet states. The donor-acceptor alignment plays a key role in the partitioning.

This work was supported by grants from the National Centre for Research and Development (PBS3/A1/17/2015).

References: [1] J. Karpiuk, Phys. Chem. Chem. Phys., 5 , 1078-1092 (2003)

[2] T. Bizjak, J. Karpiuk, S. Lochbrunner, E. Riedle, J. Phys. Chem. A, 108, 10763-10769 (2004)

[3] J. Karpiuk, E. Karolak, J. Nowacki, Pol. J. Chem. 82, 865-882 (2008).

Oral Communications


Fig.1 Structure of DCNP

Environment-sensitive photophysics of a hyperpolarizable push-pull pyrazole derivative

Kozankiewicz B.

1, Miniewicz A.

2, Morawski O.

1, Sobolewski A.L.

1


2 Faculty of Chemistry, Wrocław University of Technology

A pyrazoline derivative 3-(1,1-Dicyanoethenyl)-1-phenyl-4,5-dihydro-1H-pyrazole (DCNP,

Fig.1) has been studied for its high molecular hyperpolarizability [1]. DCNP crystallizes in the

noncentrosymmetric monoclinic space group Cc with the molecules showing the high degree of

parallelism. DCNP crystals show excel-

lent electrooptic properties [1] and

efficient second harmonic generation

[2]. Similar effects may be achieved by

poling of polymer thin films containing

polar DCNP molecules [3]. Amplified

spontaneous emission of DCNP in

polymethyl methacrylate matrix has

been observed [4] proving that in rigid

environment it is a well fluorescent

molecule. Similarily to DCVJ, the

widely-studied fluorescent molecular rotor [5], DCNP has the flexible dicyanovinyl group that

may perform twisting motion. Thus DCNP can be a good candidate for the fluorescent molecular

rotor.

The optical spectroscopic investigation of DCNP in several solvents of different polarities and

viscosities reveales that fluorescence of this molecule is sensitive to properties of the environ-

ment. The complex photophysics of DCNP arises from the presence of two rotational degrees of

freedom of the dicyanovinyl group, the torsion around the double C=C bond and the s-trans – s-

cis isomerization around the single C-C bond, that differently behave in various environmental

conditions. In protic solvents the molecule forms hydrogen bond complexes that manifest them-

selves in fluorescence decay profiles as the second, long-living component of the decay. This

may be applied as solvent proticity probe.

[1] S. Allen, T.D. McLean, P.F.Gordon, D.D. Bothwell, M.B. Hurthouse, S.A. Karaulov, J.Appl. Phys. 64,

2583 (1988)

[2] A. Miniewicz, K. Palewska, L. Sznitko and J. Lipiński, J. Phys. Chem. A 115, 10689 (2011)

[3] W. Shi, Ch. Fang, Z. Xu, Q. Pan, Q. Gu, D. Xu, H. Wei, J. Yu, Solid State Comm. 113, 483 (2000)

[4] L. Sznitko, J. Myśliwiec, K. Parafiniuk, A. Szukalski, K. Palewska, S. Bartkiewicz, A. Miniewicz,

Chem. Phys. Lett. 512, 247 (2011)

[5] S. Howell, M. Dakanali, E.A. Theodorakis, M.A. Haidekker, J. Fluoresc. 22, 457 (2012)

Oral Communications


Direct observation of the excited state structure of a model Ag(I)-

Cu(I) complex

Jarzembska K. N.1,2

, Kamiński R.1,2

, Fournier B.2, Trzop E.

2, Sokolow J. D.

2,

Chen J.2, Henning R.

3, Coppens P.

2

1 Czochralski Laboratory of Advanced Crystal Engineering, Biological and Chemical Research

Centre, Department of Chemistry, Żwirki i Wigury 101, 02-089 Warsaw, Poland 2 Department of Chemistry, University at Buffalo, The State University of New York, Buffalo, NY

14260-3000, USA 3 The Consortium for Advanced Radiation Sources, University of Chicago, Chicago, IL 60637,

USA

Heterodentate coordination complexes have been extensively studied because of their rich electronic and luminescent properties, which are of importance in the design of molecular devices. The short metal-metal contacts found in such complexes determine the nature of the lowest lying emissive states, and must be explored in order to understand their physical properties. Recent advances in time-resolved (TR) synchrotron techniques supported by specific data collection strategies and data processing procedures [1] allow for elucidation of molecular excited state geometries in the solid state. The approach has been so far successfully applied to several high-quality Laue-data sets collected at the 14-ID BioCARS beamline at the Advanced Photon Source.[2]

In this contribution we present synchrotron TR experiment results obtained for a new

solvent-free crystal form of a model complex containing Ag(I) and Cu(I) (Ag2Cu2L4, L = 2-diphenylphosphino-3-methylindole ligand).[3] This system exhibits red solid-state luminescence with a lifetime of about 1 µs. This is one of the shortest-lived excited states we have studied so far with the Laue technique. The relatively short lifetime goes along with significant structural changes observed upon irradiation, such as, the Ag…Ag distance shortening of about 0.26 Å for the excited state. The results clearly show strengthening of the Ag…Ag interactions suggesting a bond formation upon excitation.[4] The photocrystallographic findings are supported by spectroscopic measurements and quantum computations. The results confirm the triplet nature of the emissive state originating mainly from a ligand-to-metal charge transfer.

Research was funded by the NSF (CHE1213223). BioCARS Sector 14 is supported by the

NIH, National Center for Research Resources (RR007707). The APS is funded by the U.S. DoE, Office of Basic Energy Sciences (W-31-109-ENG-38). KNJ is supported by the Polish Ministry of Science and Higher Education through the “Mobility Plus” program.

[1] (a) P. Coppens, M. Pitak, M. Gembicky, et al., J. Synchrotron Rad. 16, 226 (2009); (b) J. Kalinowski,

B. Fournier, A. Makal, et al. J. Synchrotron Rad. 19, 637 (2012)

[2] T. Graber, S. Anderson, H. Brewer,et al. J. Synchrotron Rad. 18, 658 (2011)

[3] I. O. Koshevoy, J. R. Shakirova, A. S. Melnikov et al. Dalton Trans. 40, 7927 (2011)

[4] K. N. Jarzembska, R. Kamiński, et al., Inorg. Chem. 53, 10594 (2014)

Oral Communications


On photo-oxidation of single aromatic molecules

Kozankiewicz B.

Institute of Physics, Polish Academy of Sciences, [email protected]

Single-molecule optical experiments give access to properties of a selected molecule, and to the distribution of parameters that characterize a population [1]. The requirement for the mole-cules to be studied as individuals is that they have to be very efficient emitters of fluorescence and also be stable enough to emit thousands of photons at least before undergoing chemical photo-reactions to a dark compound. One of the major factors responsible for bleaching of single organic molecules, and thus limiting their use, is presence and diffusion of molecular oxygen in the neighborhood of the molecule. Molecular oxygen in its triplet electronic ground state is a relatively inert molecule but it becomes highly reactive in the lowest excited state, which is the singlet located about 7880 cm

-1 above the ground state. The main mechanism of singlet oxygen production proceeds via

interaction with the triplet state of organic molecules. In the present contribution I'll concentrate on photo-bleaching of terrylene, the compound frequently studied in the field of single molecule spectroscopy. In this case bleaching results from the encounter of terrylene and oxygen molecules [2-5]. [1] B. Kozankiewicz, M. Orrit, Chem. Soc. Rev. 43, 963 (2014)

[2] R. Kościesza, E. Luzina, D. Wiącek, J. Dresner, B. Kozankiewicz, Mol. Phys. 107, 1889 (2009)

[3] I. Deperasińska, E. Karpiuk, M. Banasiewicz, B. Kozankiewicz, Chem. Phys. Lett. 492, 93 (2010)

[4] B. Kozankiewicz, I. Deperasińska, E. Karpiuk. M. Banasiewicz, A. Makarewicz, Opt. Mat. 33, 1391 (2011)

[5] T. Christ, F. Kulzer, P. Bordat, Th. Basché, Angew. Chem. Int. Ed. 40, 4192 (2001)

Oral Communications


300 400 500 600 700

0.000

0.004

0.008

0.012

A

/ nm

Time [s]:

0.3

6

25

50

100

300

Fig.1 Experimental transient absorption spectra of 5DAll in water (pH ~ 6), λexc = 355 nm, 0.5 mJ /pulse, argon-saturated solutions

5-Deazaalloxazine: transient absorption spectra

Gierszewski M.

1, Prukała D.

1, Burdziński G.

2, Worrall D.R.

3, Sikorski M.

1

1 Faculty of Chemistry, Adam Mickiewicz University in Poznań, Umultowska 89B, 61-614

Poznań, Poland, [email protected] (M.G.) 2 Faculty of Physics, Adam Mickiewicz University in Poznań, Umultowska 85, 61-614 Poznań,

Poland 3

Department of Chemistry, Loughborough University, Loughborough, Leicestershire LE11 3TU, UK

5-Deazaalloxazine (5DAll) and its methyl derivatives have been investigated in previous studies using experimental and theoretical approaches [1-5]. So far, our attention has been concentra-

ted on the description of singlet states of 5DAll and its derivatives.

The triplet excited states of 5-deazaalloxazine (5DAll) in water and in acetonitrile have been investigated using transient ab-sorption spectroscopy. Experi-mental results are compared with theoretical calculations of the predicted energies of triplet → triplet transitions. The triplet life-time for 5DAll have been found on the microsecond time scale and the quantum yield of intersys-tem crossing for 5DAll in water has been determined as 0.43. The transient absorption spectra of 5DAll in water (pH ~ 6) are

included in Fig. 1. According to the experimental transient absorption spectra of 5DAll, the negative change of absorbance at about 360 nm is noted due to the strong ground-state deple-tion. At the same time, the positive changes of absorbance are noted at about 320 nm and 450 nm. According to our previous investigations of acid-base equilibria for 5DAll in different pH conditions, at pH ~ 6 the neutral form of 5DAll is present, without any ionic or tautomeric forms [5]. 5DAll is found as an efficient photosensitizer of singlet oxygen.

[1] D. Prukała, M. Gierszewski, T. Pędziński, M. Sikorski, J. Photochem. Photobiol. 275, 12 (2014)

[2] D. Prukała, M. Taczkowska, M. Gierszewski, T. Pędziński, M. Sikorski, J. Fluoresc. 24, 505 (2014)

[3] D. Prukała, I. V. Khmelinskii, J. Koput, M. Gierszewski, T. Pędziński, M. Sikorski, Photochem. Pho-

tobiol. 90, 972 (2014)

[4] D. Prukała, M. Gierszewski, M. Kubicki, T. Pędziński, E. Sikorska, M. Sikorski, J. Mol. Struct. 1079,

139 (2015)

[5] D. Prukała, M. Gierszewski, J. Karolczak, M. Sikorski, Phys. Chem. Chem. Phys. 17, 18729 (2015)

This study was supported by the National Science Centre under Grants No. 2013/08/T/ST4/00640 and DEC-2012/05/B/ST4/01207

Oral Communications


Photochemistry of alloxazines – past, present and …

Sikorski M.

Faculty of Chemistry, Adam Mickiewicz University in Poznań, Umultowska 89B,

61-614 Poznań, Poland, [email protected]

Lecture deals with its subject from a personal point of view. Alloxazines, flavins and flavo-proteins are a widely investigated and highly versalite group of compounds. Parcitipation of these compounds in photochemistry and photobiology processes are of particular importance in the diferent fields including biology, chemistry and medicine. During the lecture early history of photochemistry of those compounds will be recalled and some of the early experience of the lecturer will be presented. The current status of the knowledge in a field will be discussed briefly along with some predicions.

Lecture is dedicated to the memory of professor Jacek Kozioł and professor Anna Koziołowa.

The presentation was supported by the research grant DEC-2012/05/B/ST4/01207 from The National Science Centre of Poland (NCN).

Oral Communications


Fig. 1 Chlorophyll a

Transmetalation od chlorophylls – molecular mechanisms and consequences for the ground and excited states of the pigment

Łukasz Orzeł,

1 Agnieszka Drzewiecka-Matuszek,

2 Leszek Fiedor,

3 Grażyna Stochel

1

1 Faculty of Chemistry, Jagiellonian Univeristy, [email protected]

2 Jerzy Haber Institute of Catalysis and Surface Chemistry, Polish Academy of Sciences

3 Faculty of Biotechnology, Biochemistry and Biophysics, Jagiellonian University

Modifications of chlorophylls, especially those

concerning exchange of the central ion must lead to significant changes in their photophysical properties. These natural processes, occurring in plants growing on soils contaminated with heavy metals, lead directly to the loss of photosynthetic activity. Intended transmetalation, resulting from the chemical synthesis motivated, among others, by the need for new photosensitizers in photodynamic therapy, introduce changes favorable to the purpose of the designed compoud. In our research, we try to both determine the mechanisms leading to the formation of a new complex with unique properties and understand the changes which have occurred, particularly those concerning the electronic states of the pigment.

On the basis of detailed kinetic studies we were able to explain the difficulties occuring in the spontaneous exchange of magnesium ion in organic solutions and indicate a convenient way to reduce the activation barrier for the investigated processes.

1,2

Resulting metalloderivatives exhibit not only the increased energy of chlorophyll main absorption band but also quite specific properties of the excited states. They consist mainly in considerable shortening of the lifetimes of triplet states and increasing effectivity of quenching by molecular oxygen. This can be explained by the enhanced spin-orbit coupling, introduced by a metal ion.

3 An ultrafast deactivation

chanell was found in Ni-substituted chlorophyll. The exceptional photostability of the complex, together with very efficient excitation-into-heat conversion makes it a promising candidate for the application as a versatile photocalorimetric reference.

4

[1] Ł. Orzeł, Dalton Trans. 44, 6012 (2015)

[2] Ł. Orzeł, Chem. Eur. J. 14, 9419 (2008)

[3] A. Drzewiecka-Matuszek, J. Biol. Inorg. Chem. 10, 453 (2005)

[2] M. Pilch, Biochim. Biophys. Acta 30, 1827 (2013)


Oral Communications


Excited states of pyromellitic diimides - theoretical modelling

of the absorption and MCD spectra

Kukułka M.1, Andrzejak M.

2

1 Faculty of Chemistry, Jagiellonian University, [email protected]

2 Faculty of Chemistry, Jagiellonian University

The low-lying excited states of 1,2,4,5-benzenotetracarboxy diimide (1) and its

N,N’-dicyclohexyl derivative (2) have been characterized by means of TDDFT and CC2

calculations. The calculated excitation energies, electric transition dipole moments, and Franck-Condon factors have been used to obtain theoretical absorption spectra within the range of 3-6.5 eV, with the shape of the spectral bands based on the simulated vibronic activity.

Very good agreement with experiment lends credit to the calculated parameters, which have been further used in the subsequent modelling of the magnetic circular dichroism (MCD) spectra of the studied compounds. Theoretical treatment of the MCD spectra additionally requires calculating the magnetic transition dipole moments between the excited states. It is not a straightforward issue for larger systems, as it has to be done by means of the multireference methods. In the case of PMDI, sufficient accuracy at the multi-state-CASPT2 level of theory could be achieved only using the full valence π-electron active space (18 electrons in 16 orbitals).

Thus computed magnetic transition dipole moments, combined with the parameters obtained for the purpose of the absorption spectra simulation have led to the theoretical MCD spectrum that is in excellent agreement with the available experimental results.

Oral Communications


Figure. A comparison of redox properties of rutile-TiO2 and

anatase-TiO2.

Reduction of small molecules in photocatalytic systems

Wojciech Macyk, Marta Buchalska, Marcin Kobielusz, Szymon Wojtyła, Michał Pacia,

Tomasz Baran

Faculty of Chemistry, Jagiellonian University, Kraków, [email protected]

Photocatalytic reduction of small molecules is very often a key step of a photocatalytic reaction. Reduction of water or carbon dioxide can be used to convert solar energy into fuels, however, also in processes of pollutants photodegradation reduction of a small molecule (O2) influences the overall efficiency of photocatalysis. During the presentation selected examples of photocatalytic reduction of small molecules will be presented. Factors influencing these reactions will be discussed. Among them redox properties of photocatalysts are particularly important.

Recently, a new method of determination of the density of states was developed in our group. Its application enabled understanding the differences between rutile-TiO2 and anatase-TiO2. The results revealed significantly better reduction properties of rutile than anatase. Therefore the reduction of oxygen is more efficient at rutile than at anatase. On the other hand, holes generated within anatase particles are stronger oxidants than holes from the valence band of rutile, so oxidation of water to hydroxyl radicals proceeds efficiently at anatase-TiO2, but not at rutile-TiO2. These properties explain the differences in photocatalytic activities of both crystalline forms of titanium dioxide (Figure).

Acknowledgements

This work was supported by the Foundation for Polish Science within the TEAM program, grant no. TEAM/2012-9/4.

[1] T. Baran, A. Dibenedetto, M. Aresta, K. Kruczała, W. Macyk, ChemPlusChem

79, 708 (2014)

[2] E. Świętek, K. Pilarczyk, J. Derdzińska, K. Szaciłowski, W. Macyk, Phys. Chem.

Chem. Phys. 15, 14256 (2013)

[3] M. Buchalska, M. Kobielusz, A. Matuszek, M. Pacia, S. Wojtyła, W. Macyk,

submitted to ACS Catalysis.

Oral Communications


Fig.1 Density of electronic states determined for the semi-

conducting electrode made of anatase deposited at plati-

num foil and immersed in 0.1 M tetrabutylammonium per-

chlorate in acetonitrile

Spectroelectrochemical method of surface states characterization and DOS determination for semiconducting metal oxide electrodes

Kobielusz M.,

1 Świętek E,

1 Pilarczyk K.,

2,3 Szaciłowski K.,

2,4 Macyk W.

1

1 Faculty of Chemistry, Jagiellonian University, ul. Ingardena 3,

30-060 Kraków, Poland, [email protected] 2Academic Centre for Materials and Nanotechnology, 3Faculty of Physics and Applied Computer Science,

4Faculty of Non-Ferrous Metals,

AGH – University of Science and Technology, al. A. Mickiewicza 30, 30-059 Kraków, Poland

The electronic structure of a semi-conducting material strongly influences its chemica properties. It determines the progress of such processes like photo-generation, separation, transport and recombination of charge carriers. In recent years a number of publications on heterogeneous photocatalysis is increasing along with the growing num-ber of semiconductors applications as photocatalysts. More and more sophisti-cated materials designed to facilitate various photocatalytic processes are engineered. The activity of all of them is governed by interfacial redox reactions, involving electrons and holes as reduc-ing and oxidizing agents. Since the efficiencies of these processes depend on accessibility of both the adsorbed reactants and charges, the lifetimes and energies of the latters, the accurate characterization of the photocatalysts electronic stucture seems crucial.

In recent years there have been several attempts to design technics for characterization of semiconductor electronic structures, mainly for nanopowders [1,2]. We proposes modified spec-troelectrochemical method as a new technique to characterize the electronic states located close to the edge of the conduction band [3]. Also, the additional energy states localized within the bandgap were qualitatively characterized. The applicability of the method in determination of deep and shallow electron traps was confirmed. Furthermore, application of modified spec-troelectrochemical method enbles determination of the distribution of electron density of states for selected samples.

Acknowledgements The work was supported by the Foundation for Polish Science (FNP) within the TEAM

(TEAM/2012-9/4) project.

[1] M. Jankulovska, T. Berger, T. Lana-Villarreal, R. Gómez, Electrochim. Acta 62, 172-180 (2012)

[2] D. Mandal, T. W. Hamann phys. Chem. Chem. Phys., 17, 11156-11160 (2015)

[3] M. Kobielusz, E. Świętek, K. Pilarczyk, K. Szaciłowski, W. Macyk, in preparation

Oral Communications


Photocatalytic activity of neat and dye sensitized CuI toward deg-radation of organic pollutants and inactivation of microorganisms

Wojtyła S.

1, Baran T.

2, Macyk. W.

1

1 Faculty of Chemistry, Jagiellonian University, Ingardena 3, 30-060 Krakow, Poland

2 Department of Chemistry, University of Milan, Golgi 19, 20133 Milan, Italy

The degradation of biological, organic and

inorganic pollutants in water and air is an inter-esting and promising approach of photocataly-sis. Reactive oxygen species (ROS) generated on the surface of light induced photocatalyst have the ability to kill a broad range of microor-ganisms including Gram-positive and Gram-negative bacteria, endospores, fungi, algae, protozoa and viruses, as well as prions. Photo-catalysis can also lead to the degradation of endospores and microbial toxins [1]. These features of photocatalysis together with the great ability to degrade pollutants make photo-catalysis a great method of environment treat-ment. We have engaged neat and photosensi-tized copper iodide for degradation of organic dye (Acid Red 1) and inactivation of microorgan-isms (Saccharomyces cerevisiae, that has been used as a model organism) [2].

Copper iodide is a novel photocatalyst of high efficiency and attractive band structure, its band gap energy is lower than that of TiO2. Photosensitization of copper iodide with [Cu(NCS)2(phen)2] results in a shift of light absorption edge towards lower light energy and made CuI more efficient photocatalyst. Obtained results proved that the studied materials have good ability for photocurrent generation, degradation of organic dyes and inactivation of yeast. For this reason, CuI should be considered as a promising photocatalyst for environment treat-ment - removal of organic pollutants and microorganisms.

Acknowledgements

The work was supported by the Foundation for Polish Science (FNP) within the TEAM (TEAM/2012-9/4).

[1] D. Bhatkhande, S. Dhananjay, V. G. Pangarkar, A. Beenackers, J. Chem. Technol. Biotechnol. 77:

102–116 (2011) doi:10.1002/jctb.532

[2] S. Wojtyła, T. Baran. Eur. Chem. Bull. 4: 260–267 (2015)

Figure 1. Mechanism of destroying cells of yeast.

Oral Communications


O2

O2

H O2 2

OH

H O2

Excitation

e

e

e

h+h

+

h+

H O2 2

TiO2

Superoxideradical

Hydrogenperoxide

Hydroxylradical

reduction

reduction

reduction

oxidation

oxidation

h

Fig. Fate of photogenerated charges on TiO2 surface

Activation of hydrogen peroxide on TiO2

Pacia M., Mikrut P., Kobielusz M., Buchalska M., Macyk W.

Faculty of Chemistry, Jagiellonian University, [email protected]

Photocatalytic properties of TiO2 depends on its morphology, physicochemical properties,

specific surface, size, shape of crystals and on exposure of certain crystal facets. Because the overall activity is dependent on the surface ratio in recent years the interest in shape controlled synthesis of titanium dioxide has risen. Exposition of specific crystal planes results in different mechanisms of occurring photoprocesses.

The purpose of this study was to determine the fate of hydrogen peroxide in the photocatalytic systems based on titanium(IV) oxide with different cyrystal palnes exposed. TiO2 materials, such as Hombikat UV100, P25, TH-0, Tronox AK-1 and Tronox TR were tested. Additionally, several kinds of TiO2 materials with different shapes: ellipsoids, rods, cubes, cuboids, and sheet-like, were synthesized. All synthesized mate-rials were measured by XRD, to characterize the resulting poly-morph. Some semiconductors were observed using a SEM to

examine the shape of the obtained photocatalysts. Band gap for all obtained materials was determined using Tauc method. For every synthesized particles, hydroxyl radicals yield was checked. The influence of hydrogen peroxide on the OH radicals generation rate was thor-oughly investigated.

Anatase samples with exposed surfaces have been subjected to photocatalytic activity tests in the terms of hydroxyl radical production. The results showed that synthesized materials util-ized hydrogen peroxide faster than the commercial materials, and performed better than com-mercial ones.

[1] Roy, N., Sohn, Y., & Pradhan, D., ACS nano, 7, 2532 (2013)

[2] Ohno, T., Sarukawa, K., & Matsumura, M., New J. Chem., 26, 1167 (2002)

[3] Yang, H. G., Sun, C. H., Qiao, S. Z., Zou, J., Liu, G., Smith, S. C., ... & Lu, G. Q., Nature, 453, 638

(2008)

Oral Communications


Fig.1 The 6-helicene molecule

Multiphoton circular dichroism: Two- and three-photon chiroptical

light absorption

Friese, D.H. , Ruud, K.

Centre for Theoretical and Computational Chemistry, University of Tromsø – The Arctic Universi-

ty of Norway, N-9037 Tromsø, Norway

Two-photon circular dichroism has gained a lot of interest as a specialized spectroscopic technique during the past decade especially for conformational studies in proteins. In this pres-entation we show the theoretical derivation of three-photon circular dichroism, the next higher order of non-linear chiroptical light absorption. With an experimental realization of this property advantages of higher-order multiphoton spectroscopy could also be exploited for chiroptical spectroscopy as it is carried out at reasonably low wavelengths and therefore would e.g. offer a high penetration depth into living tissues which is useful for in-vivo spectroscopy.

Together with the theoretical derivation of 3PCD we will present a study on the basis set be-haviour of this new molecular property as well as an investigation of the 3PCD behaviour of the

6-helicene molecule. We will also compare the different dichroic prop-erties known so far: Electronic (or one-photon) circular dichroism, two-photon circular dichroism and three-photon circular dichroism.

Oral Communications


Are exciton-polaritons involved in non-linear emission

of a polyaniline diode?

Langer J. J., Kalisz. M., Frąckowiak E., Golczak S.

Adam Mickiewicz University, Faculty of Chemistry, Laboratory for Materials Physicochemistry and Nanotechnology, [email protected]

We wish to present a new concept of a mechanism of non-linear emission of a diode, which is formed with the use of polyaniline (PANI) micro- and nanostructures. The stimulated anti-Stokes Raman scattering (SRS) in polyaniline LED has already been observed in our laboratory [1]. The intensity of light emitted increases substantially above a threshold voltage (i.e. the elec-trical energy pumped). Intensive light pulses are generated and the light beam is often partially collimated. This is a characteristic feature of stimulated emission. However, taking into account the latest experimental results (e.g. a strong influence of magnetic field, Fig. 1), a competitive mechanism of emission, in which polaritons are involved, can be discussed [2].

We expect, this exciton-polariton based process, is the first observed in a system, which is composed of conducting polymer nanowires, strongly absorbing light as a bulk solid material.

[1] J. J. Langer, B. Miładowski, S. Golczak, K. Langer, P. Stefaniak, A. Adamczak, M. Andrzejewska, L.

Sójka and M. Kalisz, Non-linear optical effects (SRS) in nanostructured polyaniline LED, J. Mater.

Chem., 20 (2010) 3859–3862 [2] C. Schneider, A. Rahimi-Iman, N. Young Kim, J. Fischer, I. G. Savenko, M. Amthor, M. Lermer, A. Wolf, L. Worschech, V. D. Kulakovskii, I. A. Shelykh, M. Kamp, S. Reitzenstein, A. Forchel, Y. Yamamo-to & S. Höfling, An electrically pumped polariton laser. NATURE, 497 (2013) 348-352.

Fig.1 Emission spectra of PANI diode recorded above a threshold voltage without magnetic field and in the presence of magnetic field.

Oral Communications


New luminescent materials based on ortho-phenylenediboronic

acid – from crystal engineering to spectroscopic properties

Jarzembska K. N.1, Kamiński R.

1, Durka K.

2, Kubsik M.

3, Nawara K.

4, Luliński S.

2

1 Czochralski Laboraroty of Advanced Crystal Engineering, Biological and Chemical Reseach

Centre, Departmenf of Chemistry, University of Warsaw, Żwirki i Wigury 101, 02-089 Warsaw, Poland, [email protected]

2 Department of Chemistry, Warsaw University of Technology, Noakowskiego 3, 00-664 War-

saw, Poland 3 Department of Chemistry, University of Warsaw, Pasteura 1, 02-093 Warsaw, Poland

4 Institute of Physical Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, 01-224 War-

saw, Poland

Arylboronic acids have already found many applications in diverse areas of chemical science, such as organic synthesis, catalysis or crystal engineering. Quite recently we have worked on para- and ortho-phenylenediboronic acids.[1,2] In the present study, we focus our attention on a new class of adducts based on the latter compound.

It occurred that a simple one-pot reaction of ortho-phenylenediboronic acid with 8-

hydroxyquinoline results in a new photoactive species. The reaction proceeds smoothly even in solvent-free conditions (mechanochemistry) and allows obtaining many modifications of such complexes (regarding both the acid and N-donor compound) in high yield. It was possible to crystallize and structurally characterize many of these systems, including several fluorinated derivatives and various solvatomorphs.

Additionally, luminescent properties of the studied complexes were investigated using the

time-resolved spectroscopy, both in solution and in the solid state. The recorded emission spectra indicate the possibility of tuning the colour of the emitted light in the visible regime (from blue to orange). The determined lifetimes are of nanosecond order (9 – 15 ns), which suggests that the main contribution to the emitted light comes from the fluorescence process (singlet-to-singlet transition) what is further supported by the DFT calculations. Theoretical results show also that the charge transfer processes occur mostly in the quinoline ring fragment. The emission quantum yields determined in solution are in the range of 10 to 30%. The lifetimes and quantum yield values are highly dependent on the number of fluorine substituents in the acidic part of the molecule. The more the F-substituents present, the lower the corresponding values.

[1] K. Durka, K. N. Jarzembska, R. Kamiński, S. Luliński, J. Serwatowski, K. Woźniak Cryst. Growth

Des. 12, 3720 (2012)

[2] K. Durka, K. N. Jarzembska, R. Kamiński, S. Luliński, J. Serwatowski, K. Woźniak, Cryst. Growth

Des. 13, 4181 (2013)

Oral Communications


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SHIM-POL is an exclusive representative of SHIMADZU-KRATOS CORPORATION in Poland. We offer UHPLC, HPLC, GC chromatographs; MS systems: GC-MS(MS), LC-MS(MS), LCMS-IT-TOF and MALDI-TOF-TOF; UV-Vis, FTIR, RF and AAS spectrophotometers; TOC; X-ray Fluorescence Spectrometers (EDX). We also deliver spectrometers for surface analysis such as ESCA-XPS,SIMS,ISS and Auger. The offer is completed with equipment from the following companies: PHENOMENEX, ANTEC LEYDEN, RHEODYNE, CHROMACOL, PEAK SCIEN-TIFIC generators, PIKE – IR accessories. Automatic SPE extraction, drying and concentration with apparatus manufactured by HORIZON TECHNOLOGY and the supercritical liquid extraction and high pressure chemistry manufactured by SUPERCRITICAL FLUID TECHNOLOGIES.

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High-symmetry compact structures are preferred equilibrium

configurations of LinFn+1– (n=2–5) superhalogen anions

Wileńska D.

1, Skurski P.

1, Anusiewicz I.

1

1 Department of Chemistry, University of Gdańsk, [email protected]

Theoretical ab initio investigation performed for the LinFn+1

– anionic systems (n=2-5)

revealed that their most stable isomers correspond to the high-symmetry compact molecular structures exhibiting relatively large excess electron binding energies (exceeding 10 eV). The formation of these polynuclear superhalogen anions was found to proceed spontaneously by a consecutive barrier-less attachment of neutral LiF molecules. Such a negative anionic cluster structural growth was predicted to be driven mainly by a successive increase of its electronic stability (manifested by an enlargement of the vertical electron detachment energy).

Posters


Luminescent materials based on lanthanide ions incorporated into

silica-based matrixes

Cybinska J.1,2

, Wilk M.1, Komorowska K.

1, Kargol M.

1

1 Department of Nanotechnology, Wrocław Research Centre EIT+, Poland,

2 Faculty of Chemistry, Wrocław University, Poland, [email protected]

The rapid development of technology stimulates interest in substances that as a result of

excitation can efficiently emit light,so-called phosphors materials. Lanthanide ions (Ln3+

) doped materials play a very important role in several high-tech sectors as they have found a whole variety of applications that are widely understood in the light industry. These materials are main-ly used to produce the phosphor mix contained in fluorescent lamps. They are also used in scintillators/X-ray phosphors, energy-saving lighting, bio-labels, storage and persistent phos-phors, and laser materials. All of these technologies demand luminescent materials with higher efficiency and stability in terms of their performance.

Fig. 1 Monolithic sample image after calcination, before (left) and after (in the middle) the Eu

3+ ions introduc-

tion. The emission spectrum of aluminosilicate monoliths doped with Eu3+

ions by the sol-gel method. The Eu

3+ concentration is 2 % in relation to Si. The spectrum was obtained under excitation at 393 nm. (right)

The incorporation of the highly efficient lumionphors into the silica-based matrixes should lead to an increase of their stability and improving the optical properties. It allows also to produce thin films or form synthetized materials in desirable shape much easy to handle. The main ad-vantage of the sol-gel-route combined with liquid crystal templating method is the possibility to prepare monolithic materials at low temperatures and ambient conditions, thus the organic mol-ecules can be incorporated into silica matrixes without being damage. At the temperatures re-quired by sol-gel processing the organic molecules structures are preserved and the time of reaction is relatively short. Optimization of the synthesis and drying conditions together with selection of the inorganic and organic components determine the morphology, the molecular structure and properties of the hybrid. Moreover, for the application as optical materials it is very important that silica glasses are highly transparent, so they can be used in very broad spectral range. Acknowledgement The work was supported by Wroclaw Research Centre EIT+ within the project "The Application of Nano-technology in Advanced Materials” - NanoMat (POIG.01.01.02-02-002/08) co-financed by the European Regional Development Fund (Operational Programme Innovative Economy, 1.1.2).

Posters


Novel strong superacids HAlnF3n+1 (n=1-4)

Czapla M.

1, Skurski P.

1

1 Faculty of Chemistry, University of Gdańsk, [email protected]

Novel strong superacids are proposed and investigated on the basis of ab initio calculations.

The gas phase acidity of the HAlF4, HAl2F7, and HAl3F10 systems evaluated by the estimation of the free Gibbs energies of their deprotonation reactions were found significant and comparable to the corresponding value characterizing the HTaF6, whereas the strength of the HAl4F13 acid was predicted to exceed that of the HSbF6 acid (the strongest liquid superacid recognized) [1]. The deprotonation energies of the HAlnF3n+1 acids (n=1-4) turned out to be closely related to the electronic stabilities of their corresponding (AlnF3n+1)– anions [2].

This research was supported by the Polish Ministry of Science and Higher Education grant No. DS 530-8376-D499-15. The calculations have been carried out using resources provided by Wroclaw Centre for Networking and Supercomputing (http://wcss.pl) grant No. 350.

[1] G. A. Olah, G. K. Prakash, J. Sommer, Science 206, 13 (1979)

[2] C. Sikorska, P. Skurski, Chem. Phys. Lett. 536, 34 (2012)

Posters


Fig.1 The equilibrium structure of the DAA(Ala)12 molecule in the

gas phase shown as alpha-helices (represented by ribbons)

sharing the central DAA unit.

Double amino acid – A novel molecule enabling peptide

interpenetrating structures

Freza S., Marchaj M., Skurski P.

Faculty of Chemistry, University of Gdańsk, Wita Stwosza 63, 80-308 Gdańsk, Poland

[email protected]

Peptide chains might be linked with one another using various external bifunctional molecules. We postulate an existence of a novel molecule termed ‘double amino acid’ containing four func-

tional groups connected to one C atom ((NH2)2C(COOH)2). Using correlated ab initio approach (QCISD and MP2 methods) we provide its structure, simulated IR spectrum and verify its stability in gas and aqueous phases. The proposed double amino acid is predicted to enable the design of a novel family of interpenetrating peptides in which it is expected to serve as a built-in amino acid residue that might be shared by two independent peptide chains.

Posters


250 300 350 400 450 500 550 600

0,0

0,4

0,8

1,2

1,6

Ab

so

rba

nce

N

NHN

N O

O

CH2

H3C

H3C

CHOH

CHOH

CHOH

CH2OH

Wavelength / nm

Fig.1 Changes in absorption spectrum of riboflavin upon irradiation (λ=366nm)

Photochemical reactions of vitamin B2 and its derivatives

Insińska-Rak M.

1, Golczak A.

1, Sikorski M.

1

1 Faculty of Chemistry, Adam Mickiewicz University in Poznań, [email protected]

Flavins are compounds of considerable biological function. Riboflavin (vitamin B2), FMN

(flavin mononucleotide) and FAD (flavin adenine dinucleotide) are the best known

representatives of this group of compounds. Flavin derivatives, present in enzymes and

photoreceptors, are involved in

metabolic processes occurring in

living cells [1]. Riboflavin

undergoes photoreactions with

nucleic acids and sensitizes

destruction of tumour cells and

intra- and extra-cellular HIV

particles. Some research points

out antitumor activity of riboflavin

derivatives and their potential role

in therapy of many other diseases

[2]. There is known their active

part in pathogene destruction and

inactivation of many viruses and

bacteria [3,4]. Due to the fact that for flavins activity in diverse redox transformations is

responsible isoalloxazinic core, thorough investigation of its spectral, photophysical and

photochemical properties was undertaken, as the step in explaining flavins reactivity in nature.

Results of photochemical experiments carried out on some flavin analogues (Fig.1), with using

HPLC analysis and with suggested structures of photoproducts are presented. Study performed

within grant UMO-2011/01/D/ST4/0499 and 2012/05/B/ST4/01207 from the National Science

Centre in Poland.

[1] W. Holzer, J. Shirdel, P. Zirak, A. Penzkofer, P. Hegemann, R. Deutzmann, E. Hochmuth, Chem.

Phys., 308, 69 (2005)

[2] H. I. Ali, N. Ashida, T. Nagamatsu, Bioorgan. Med. Chem., 16, 922 (2008)

[3] F. Corbin, Int. J. Hematol., 76, 253 (2002)

[4] H. L. Reddy, A. D. Dayan, J. Cavagnaro, S. Gad, J. Li, R. P. Goodrich, Transfus. Med.

Rev., 22, 133 (2008)

Posters


16000 20000 24000 28000

0.0

0.2

0.4

0.6

0.8

1.0

16000 20000 24000 28000

0.0

0.2

0.4

0.6

0.8

1.0

lum

ine

scen

ce

in

ten

sity [a

.u]

wavenumber [cm-1]

0.05-0.45

1.0-4.0

50-100

MGLNN5 in

BTN 77K

Fig. 1 Time-resolved dual phosphorescence of MGLNN5.

Radiative and non-radiative deactivation of triarylmethane lactones

and lactams in 1CT and 3CT states

Majsterek E.1, Piechowska J.

2, Majka A.

2, Karpiuk J.

1


2 Institute of Physical Chemistry, Polish Academy of Science

Ultrafast (~150 fs) photoinduced electron transfer (ET) in malachite green lactone (MGL), a

donor–acceptor, [D–A], molecule, produces quantitatively [1-2] a charge separated singlet state (μe ~25 D) with a structure of covalently bound radical ion pair (RIP),

1[D

•+–A

•–]. Radiative charge recombination of

1[D

•+–A

•–] is accompanied by spin flip to yield phosphores-

cent 3[D

•+–A

•–] triplet state, which subsequently deactivates

via return ET to donor-centred triplet state, [3D*–A], and to

triplet biradical, 3[D–A

••]*, produced upon lactone ring open-

ing [1]

. The dynamics of (at least some of) these ET pro-cesses are strongly coupled to C–O vibrational mode in the lactone ring, are not controlled by

solvation [2, 3]

and show strong dependence on the D–A alignment. The objective of our research is to study the effect of structural modifications in the acceptor subunit, in particular the replacement of oxygen in the lactone ring with other heteroatom, on the photophysics of the D–A system and the kinetics of the ET processes in singlet and triplet state. To this end we have synthe-sized hydrazine derivatives of MGL (e.g., MGLNN5) and studied them with room and

low temperature luminescence spectros-copy. The results obtained with steady-state and time-resolved techniques al-lowed us for demonstrating that, on the singlet state level, MGLNN5 shows essen-tially the same photophysics as MGL, In

the triplet manifold, dual phosphorescence (Fig. 1) shows that the relaxation path of MGLNN5 is analogous to that of MGL, except for MGLNN5 does not show the C-heteroatom bond cleveage

and the 3[D–A

••]* biradical is not observed.

This work was supported by grants from the Ministry of Science and Higher Education (N N204 127540) and the National Centre for Research and Development (PBS3/A1/17/2015).

References:

[1] J. Karpiuk, PCCP, 5 , 1078-1092 (2003)

[2] T. Bizjak, J. Karpiuk, S. Lochbrunner, E. Riedle, J. Phys. Chem. A, 108, 10763-10769 (2004)

[3] J. Karpiuk, A. Majka, E. Karolak, J. Nowacki, manuscript in preparation.

O

N N

O

NNH2

N N

O

MGL MGLNN5


Posters


0

5000000

10000000

15000000

20000000

25000000

350

400

450

500

550

600

650

0

5000000

10000000

15000000

20000000

25000000

350

400

450

500

550

600

650

300 320 340 360 380 400 420 440 460

Fig.1 Contour map of total fluorescence spectra of 9-methyl-

5-deazaalloxazine at pH 6.

Photophysical properties of alloxazine derivatives in dependence

of pH

Prukała D.1, Sikorski M.

1, Gierszewski M.

1

1 Applied Photochemistry Lab, Faculty of Chemistry, Adam Mickiewicz University, Poznań

[email protected]

The photophysical properties of lumichrome (7,8-dimethylalloxazine) derivatives and 5-deazaalloxazine (or 5-deazaisoalloxazine) derivatives at different pH were characterized using UV/Vis steady-state and time-resolved techniques. The absorption, fluorescence, synchronous fluorescence spectra and total fluorescence spectra of their neutral and/or ionised form are discussed and compared. The “alloxazinic” structures of the N(10) cation of 5-deazaalloxazine and N(1) cation of 10-ethyl-5-deazaisoalloxazine in the ground state are presented. Contrary to that the structures of these cations in their excited states have “isoalloxazinic” forms. Additionally, we concluded that

monoanions with the negative charge situated at the N(3) atoms of the molecules of alloxazines and 5-deazaalloxazines have “alloxazinic” forms, both in the ground and in the excited states. But, the monoanions formed by hydrogen abstraction from N(1)-H groups, have “isoalloxazinic” forms in both states. Also N(1,3) dianions show “isoalloxazinic” shaped” absorption and emission spectra, which proves their “isoalloxazinic” structures.

The characteristic pKa values for protonation/deprotonation steps of studied compounds in

the ground and in the excited states are shown and compared.

The measured excited state lifetimes of the individual forms of each compound at different pH are presented. The fluorescence of some acidic and neutral forms of the investigated com-pounds is quenched by protons. The fluorescence of the cationic form of 5-deazaalloxazine is quenched in a dynamic process. But the fluorescence quenching of the neutral forms of some of 5-deazaalloxazines operates by both static and dynamic mechanism.

This study was supported by the research grant DEC-2012/05/B/ST4/01207 from The Na-tional Science Centre of Poland.

[1] N. Lasser, J. Feitelson, Photochem. Photobiol. 25, 451 (1977)

[2] A. Tyagi, A. Penzkofer, Photochem. Photobiol. 87, 524 (2011)

[3] D. Prukała, E. Sikorska, J. Koput, I. Khmelinskii, J. Karolczak, M. Gierszewski, M. Sikorski, J.

Phys.Chem., A 116, 7474 (2012)

[4] D. Prukała, M. Gierszewski, T. Pędziński, M. Sikorski, J. Photochem. Photobiol. 275, 12 (2014)

[5] D. Prukała, M. Gierszewski, J. Karolczak, M. Sikorski, Phys. Chem. Chem. Phys. 17, 18729 (2015)

Posters


ek

ee ke

kk

PT

PT

PT

PT

(0.00)

ee(0.02)

(0.03) ke[0.12]

kk

(0.00)

[0.11]

ek

(0.03)

[0.12]

[0.11]

O1H / Å

O2H

/ Å

E

N

N

N

O1

N

O2

H

H

N

N

N

ON

O H

H

N

N

N

ON

O H

H

N

N

N

ON

O

H

Hek

ee ke

kk

PTPT

PTPT

PT

PT

PT

PT

(0.00)

ee(0.02)

(0.03) ke[0.12]

kk

(0.00)

[0.11]

ek

(0.03)

[0.12]

[0.11]

(0.00)

ee(0.02)

(0.03) ke[0.12]

kk

(0.00)

[0.11]

ek

(0.03)

[0.12]

[0.11]

O1H / Å

O2H

/ Å

EE

N

N

N

O1

N

O2

H

H

N

N

N

ON

O H

H

N

N

N

ON

O H

H

N

N

N

ON

O

H

H

Fig.1 Four oxo-hydroxy tautomers of DSA molecule

Ferroelectric molecular switching based on double proton transfer: dynamical simulations and ab initio calculations

Rode M. F.

1, Jankowska J.

2, Sobolewski A.L.

1


2 College of Inter-Faculty Individual Studies in Mathematics and Natural Sciences,

University of Warsaw

In this communication we report ab initio and on-the-fly dynamics predictions of the variation

of the electric-field induced double proton transfer (DPT) reaction mechanism in the model Schiff base molecule: (2Z)-1-(6-((Z)-2-hydroxy-2-phenylvinyl)pyridin-3-yl)-2-(pyridin-2(1H)-ylidene)ethanone (DSA)

[1,2].

In the ground electronic state, the DSA molecule possesses four enantiomeric forms (see Fig.

1), which are interconnected by the transfer of two protons engaged in two hydrogen bonds. Both these protons may undergo barrierless transfer from the ee form toward kk upon exposure to

the electric field applied to the system along the main molecular axes.

[3] The reversible reaction,

from kk toward ee, is also possi-

ble if the field is applied in oppo-site direction so the model mole-cule may function as a molecular switch. Both ab initio and dynam-

ical studies show that, in the lack of the external stimuli, the DPT reaction between the ee and kk

forms is a two-step-wise reaction, while a synchronous concerted

DPT process is blocked by an energy barrier.[4]

The situation changes when an external electric field is applied to the molecule. The dynamics results indicate that if the electric field is of suffi-cient magnitude, the synchronous downhill DPT process becomes dominating. The conclusion emerging from the obtained results indicates that the applied electric field may induce the dou-ble proton transfer process in a reversible fashion by modulation of the shape of the potential energy surface. Dynamical calculations performed for the DSA molecule placed in an external electric field

give insight into the mechanism of the double proton transfer in the system. The results indicate the mechanism of the DPT reaction is sensitive to the magnitude of electric field applied.

References [1] A. Grabowska, K. Kownacki, J. Karpiuk, S. Drobin, Ł. Kaczmarek, Chem. Phys. Lett. 267, 132 (1997) [2] A. Accardi, I. Barth, O. Kuhn, J. Manz, J. Phys. Chem. A, 114, 11252 (2010) [3] A. A. Arabi, C. F. Matta, Phys. Chem. Chem. Phys. 13, 13738 (2011) [4] J. Jankowska, J. Sadlej, and A. L. Sobolewski, Phys. Chem. Chem. Phys. 17, 14484 (2015) [5] M. F. Rode, A. L. Sobolewski, Chem. Phys. 409, 41 (2012) [6] J. Jankowska, M. F. Rode, J. Sadlej, A. L. Sobolewski, ChemPhysChem. 13, 4287 (2012)


Posters


Utilizing fluoroxyl groups as ligands in superhalogen anions: an ab initio study of the M(OF)k+1

– systems (M=Li, Na, K, Be, Mg, Ca, B, Al)

Sikorska C.1

1 Laboratory of Molecular Modeling, Department of Theoretical Chemistry, Faculty of Chemistry,

University of Gdansk, [email protected]

The existence of superhalogens was predicted in 1981 by Gutsev and Boldyrev [1], who proposed a simple formula describing one class of these compounds, MXk+1. According to their findings, superhalogen is neutral system containing the central atom M (the main group or the transition metal atom) decorated with k+1 halogens (where k is the maximal formal valence of the atom M) and is capable of forming stable anionic system having relatively large excess electron binding energy (exceeding the electron affinity of chlorine atom equal to 3.62 eV)) [2]. Exploring various new superhalogen species is primarily focused on studying larger molecular clusters that are capable of forming strongly bound anions. It seems that searching for molecu-lar systems capable of binding an excess electron extremely strongly might be performed either by designing novel polynuclear superhalogen species (e.g. according to MnXn·k+1 formula; where M is the main group or transition metal atom, X is a halogen atom, k is the maximal formal va-lence of the atom M, whereas n indicates the number of central atoms in the system) [3,4] or by inventing new strong electron acceptors. Our contribution to the studies on the possible VDE limit includes: (i) investigating the issue of saturation of the excess electron binding energy in a series of polynuclear superhalogen anions [3], (ii) designing a superhalogen utilizing 9-electron systems (i.e. isoelectronic with F atom) as alternative ligands [5], and (iii) exploring the im-portance of so-called collective effects [6].

The main goal of this contribution [7] was to investigate the issue of the existence and stabil-ity of various anions designed to match the M(OF)(k+1)

− formula, in which central atom M (the

main group atom, i.e. Li, Na, K, Be, Mg, Ca, B, and Al) is linked to k+1 OF ligands (where k is the maximal formal valence of the atom M). In particular, we decided to verify whether such systems are indeed thermodynamically stable and the electronic stabilities of the resulting ani-ons exceed those obtained with the VII main group elements. The representative species, such as Li(OF)2

−, Na(OF)2

−, K(OF)2

−, Be(OF)3

−, Mg(OF)3

−, Ca(OF)3

−, B(OF)4

−, and Al(OF)4

−, were

designed and studied at the OVGF/6-311+G(3df)//MP2/6-311+G(d) level. The lowest and high-est electron binding energies for the species considered were found for the Na(OF)2

− (5.151 eV)

and Al(OF)4− (7.566 eV), respectively [7].

[1] G.L. Gutsev, A.I. Boldyrev, Chem Phys 56 (1981) 277.

[2] H. Hotop, W.C. Lineberger, Journal of Physical and Chemical Reference Data 14 (1985) 731.

[3] C. Sikorska, P. Skurski, Chem Phys Lett 536 (2012) 34.

[4] A.N. Alexandrova, A.I. Boldyrev, Y.J. Fu, X. Yang, X.B. Wang, L.S. Wang, J Chem Phys 121 (2004)

5709.

[5] C. Sikorska, S. Freza, P. Skurski, I. Anusiewicz, J Phys Chem A 115 (2011) 2077.

[6] C. Sikorska, P. Skurski, Mol Phys 110 (2012) 1447.

[7] C. Sikorska, Chem Phys Lett (2015) 10.1016/j.cplett.2015.08.043.

Acknowledgments

This work was supported by the Polish Ministry of Science and Higher Education (MNiSW) Grant No.

0560/IP3/2013/72. C.S. thanks the European Social Fund for granting her with a fellowship in frame of the project

Development Program of the University of Gdansk in areas of Europe 2020 (UG 2020)” supported by European

Human Capital Operational Program.

Posters


Antenna role of the (HAlF4)

- dipole-bound anionic state in the superacid fragmentation process

P. Skurski, M. Czapla

Department of Chemistry, University of Gdańsk, [email protected]

The excess electron attachment to the HAlF4 superacid molecule was studied by employing

ab initio CCSD(T) and MP2 methods and purposely suited aug-cc-pVTZ+4s4p3d basis set. The results indicate that the HAlF4 molecule, due to its polarity, may attract a distant excess electron and form a dipole-bound anionic state whose vertical electron binding energy is 1106 cm

-1. The

initially formed (HAlF4)– anion of dipole-bound nature undergoes an immediate structural

reorganization driven by the (AlF4)– strongly-bound superhalogen anion formation. The potential

energy surface analysis leads to the conclusion that the (HAlF4)–

→ (AlF4)– + H transformation

should proceed spontaneously and involve the simultaneous structure relaxation of the AlF4 moiety (in the direction allowing to approach the tetrahedral geometry) and the excess electron density migration from the area outside the molecular framework to the valence AlF4 region. The fragmentation of the HAlF4 superacid molecule is predicted to be the final effect of the excess electron attachment process. The important antenna role of the initially formed (HAlF4)

– dipole-

bound anionic state is discussed.

Fig. 1 The HAlF4 superacid binds an excess electron (initially – due to its dipole potential) and undergoes a spontaneous fragmentation that leads to the H atom and AlF4

– superhalogen anion

Posters


Planar, fluorescent push–pull system that comprises benzofuran

and iminocoumarin moieties

Węcławski M.K1, Gryko D. T.

1

1 Institute of Organic Chemistry, Polish Academy of Sciences, [email protected]

Previously unknown, vertically linked heterocycles comprised of benzofuran and iminocoumarin moieties have been synthesized directly from 1,5-dibenzoyloxyanthraquinone and arylacetonitriles via double Knoevenagel condensation followed by formal HCN elimination.

1 The structural assembly of fully conjugated, electron-rich benzofuran and electron-

deficient iminocoumarin is responsible for the strongly polarized nature of these heterocycles which translates into their polarity-sensitive fluorescence.

[1] Marek K. Węcławski, Till T. Meiling, Arkadiusz Leniak, Piotr J. Cywiński, and Daniel T. Gryko, Org.

Lett. 17, 4252-4255 (2015)

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