project description;agust/rannsoknir/projectdescription.pdf · photorupture channels. f) most...

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Project Description;

Molecular photoruptures; energy properties and mechanisms

Content list:

pages:

A. State of the art …………………………………………………….. 2 B. Scientific objectives and originality……………………………….

a) Objectives b) Originality

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C. Research methodology, time plan and milestones………………… 8 C. a) Research methodology.

C.a. 1) Quantitative, qualitative and energy resolved analysis of radicals and ions formed by laser multiphoton absorption……………………….

8

C.a.2) Data from A(see above) are analyzed by use of simulation models developed within the research group at University of Iceland……………….

10

C.a.3) Tracking Photorupture paths 1) by femtosecond laser spectroscopy at Bergen University and 2) by kinetic energy measurements of fragments in Germany………………………………..

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C.a.4) Ab initio spectroscopic parameters and REMPI Spectra……………………………………………………

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C.b) Project plan………………………………………………… 15 C.c) Time plan and project emphasis………………………….. 16

D. Co-operation (foreign and domestic) and collaborators contributions, based on present status………………………….

16

E. Gradute student contributions (partly repeted above). 18 D-E. Estimated contributions in terms of manpower / man-month (mm) 18 F. Proposed deliverables and impacts………………………………….. 19 G. Proposed publications of results…………………………………….. 20 References……………………………………………………………….. 20

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A. State of the art Molecular photoruptures (i.e. photodissociation and photoionization) play vital rule in processes such as,

a) –ozone depletion, where chlorine atoms react with ozone after photodissociation of chlorine containing compounds.

b) –formations of organic molecules in interstellar space, which are believed to occur by reactions of ions and/or radicals after photoruptures of smaller compounds.

c) – photosynthetic processes as alternative processes for productions of chemicals in industry or pharmacy.

d) Capability and expertise to perform research studies in the above mentioned fields (a-

c) at University of Iceland is based on a facility which has been built up in recent years to do Resonance Enhanced MultiPhoton Ionization (REMPI) experiments and detailed analysis.

e) Various methods have been used to study photodissociation and photoionization processes in molecules. Most of these methods are based on the use of lasers or laser spectroscopy. i) Recently energy-excitations and spectroscopic methods based on the use of ultra-short laser pulses on the femtosecond time scale (10-15 sec.) have allowed such processes to be studied in detail as a function of time. ii) Kinetic energy resolved measurements of ion products in photoionization processes are powerful tools to study photorupture channels.

f) Most theoretical work on molecular properties deal with molecules in ground electronic states. Recently number of standard ab initio methods have been developed to handle excited states of molecules which wait to be approved.

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a) Generally it is believed that ozone depletion due to chlorine containing reagents (RCl) such as the CFC´s is due to photodissociation processes of the molecules in the stratosphere forming chlorine atoms (Cl) [1-3]. The chlorine atoms are reactive radicals catalyzing reaction of ozone with oxygen atoms: RCl + hν � Cl + R; photodissociation; hν represents a photon. O3 + Cl � ClO + O2 ClO + O � O2 + Cl This kind of information have caused reduction in production of CFC worldwide, as is well known. In addition to the CFC´s various other basic chlorine containing compounds can release chlorine atoms by photodissociation in the stratosphere, such as chlorine (Cl2) and hydrogen chloride(HCl). These can either be formed in the stratosphere after photodissociation of CFC´s or by diffusion from the earth surface. In recent years the photochemistry research group at University of Iceland has been involved in studies of these molecules and other related compounds, mainly to map molecular energy structures [4-24]. Limited information are available about transfer processes between energy states and the actual photodissociation processes on a quantum energy level scale. In last few years two research groups have used the photofragment imaging technique coupled with REMPI for studying the hydrogen halides to reveal several ionization channels[25-29]. Very recently our group has

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developed and used a two-dimensional REMPI (2D-REMPI) technique to characterize and quantify state transitions within electronically excited HCl molecules. This work has been accepted for publication in J. Chem. Phys. in November, 2008[24].

b) Generally reactions of ions and radicals formed by photorupture of small molecules or

atoms in the interstellar medium are believed to be the source of bigger molecules. Big organic molecules, formed in such way, along with water molecules, could be the source of life in space analogous to that on earth[30-32]. Examples about rupture- and reaction- processes important for formation of basic ions and moleculs in organic- and bio-chemistry are seen in the figure below (Figure 1). Due to interests along these lines there has been a growing emphasis on studying photorupture channels of small molecules in the field of astrochemistry [33-35]. Just recently our research group performed studies along these lines on photorupture of acetylene[36]. In a paper which we published in Chem. Phys. Letter this year[36] , photodissociation channels of neutral acetylene molecules are shown to be important channels for further ion formations from the fragments.

Figure 1. Ion and molecular formation processes following cosmic and UV radiations in interstellar space.

c) Emphasis on photoassisted synthesis is growing in the chemical industry and

pharmacy. Reactions which do not easily occur by traditional means by controlling temperature or pressure conditions may occur more easily by photoassisted pathways. Classical example is isomerization of the organic molecule stilbene and its derivatives[37]. The cis-conformers of stilbene compounds are difficult to produce by

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thermodynamic means since the trans conformers are more stable, hence are the major species formed at thermal equilibrium. Electronically excited species are formed by photoexcitation of a mixture of stilbene-isomers in the visible and UV spectral region. The π bond-rupture mechanisms involved in the isomerization process differ largely in the excited state compared to that in the ground state. (See figure 2). Thus, approximately 90% cis- stilbene (10 % trans-stilbene) is formed by photolysis[38]. The photochemistry research group at University of Iceland has worked in this field and published papers on the effects of substituents on photostationary states of stilbene derivatives[39, 40].

Excitedstates

Groundstates

Energy

Figure 2. Photoisomerization af stilbene.

d) Capability, expertise and facility to perform research activities in the above mentioned

fields at University of Iceland: Facility to perform resonance enhanced multiphoton ionization (REMPI ) studies of molecules has been built and developed in the Science Institute, University of Iceland in recent years. First, it involves use of equipments suitable to perform multiphoton absorption and ionization of molecules, using high energy laser pulses, as described in more detail below in the section „C.a) Research methodology“. Second it involves a simulation analysis technique which has been used and developed within the research group and allows determination of molecular energy properties. Descriptions of work in this field can be viewed in numerous publications by the group listed in enclosed publication lists. Just recently a new high-power and high-efficiency dye laser, bought by supports from RANNIS and the University of Iceland research fund, has been inserted

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into the equipment set-up. This has improved measurement sensitivity and accuracy tremendously. Within the last year the research group has worked on developing a model and an analysis technique, based on ion intensity interpretations coupled with perturbation theoretical treatment to evaluate state interaction strengths and contributions to photorupture processes. Results relevant to photorupture of the the molecule HCl will appear in J. Chem. Phys., November issue, this year (2008)[24].

e) i) Femtosecond spectroscopy. Following development of femtosecond (10-15 s) laser pulse equipments before about 1980 the use of the technique to study processes on this timescale has grown tremendously. Among processes which physical chemists have emphasized to study by using this technique are molecular dissociations, which typically occurs within picoseconds (say in 10-12 - 10-13 sec). Professor Ahmed Zeweil in Caltec., who was nominated the nobel price in 1999 for his studies, is among pioneers in this field[41, 42]. Typical experiments in this field are based on energy excitations of molecules by use of femtosecond laser pulses followed by absorption measurements by femtosecond pulses (see figure 3). In those cases laser pulses are typically focused on a molecular beam in a gas phase (see figure 4) followed by laser pulses from the same laser source after a delay on the femtosecond time scale for absorption measurements. The time delay is performed by increasing the path of the absorption (latter) pulse relative to that of the excitation(former) pulse. As long as the absorption depends on the distance between the atoms in the dissociating bond the dissociation process can be mapped indirectly by performing such measurements as a function of the time delay. Experiments of this kind require sophisticated and expensive equipments in a vibration-free laboratory. One such is the “Bergen multiphoton Laboratory” in the physics department, University of Bergen run by the applicants collaborators. The main applicant and his coworkers have been involved in femtosecond laser analysis before, relevant to photoisomerization studies of the stilbene derivatives mentioned above. This is presented in reference[39]. ii) The velocity map imaging technique where photoions and/or photoelectrons with the same initial velocity vector after dissociation / ionization are mapped onto the same position on a detector is a powerful tool to investigate photorupture mechanisms[25-29, 43-45].

A-B#

A-B

A + B

Formation by use offemtosecond laser pulses

Absorption measurements by femtosecond laser pulses

A-B#

Figure 3; Femtosecond analysis of an AB bond rupture.

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Figure 4. Schematic diagram showing a femtosecond experiment. f) ab initio calculations:

Most theoretical work relevant to molecular properties deal with molecules in ground electronic states. Recently number of standard ab initio methods have been developed to handle excited states of molecules. Equation-of-motion coupled cluster theory (EOM-CC)[46] has been shown to reproduce experimental excitation energies very well in certain cases [47]. It is of great interest to apply such methods at different levels with a number of basis sets to study the potential energy curves relevant to electronic excitations and photorupture processes.

B. Scientific objectives and originality; a) Objectives:

Knowledge of photorupture (i.e. photodissociation and photoionization) processes, important in fields such as ozone depletion and formation processes for organic molecules in interstellar space, on a quantum energy level scale, is limited. In the past, the photochemistry research group at University of Iceland, has emphasized to study energy properties of electronically excited state of molecules. Very recently we started to look at energy transfers between excited states and relevant photorupture channels in molecules. These first attempts to study photorupture channels have proven promising as seen in our most recent publications this year on acetylene[36] and hydrogenchloride[24]. We now whish to make use of our former experience and knowledge about excited state molecular species and the facility which has been built within University of Iceland and expand our work towards studying photorupture channels of molecules important in the above mentioned fields as well as in the field of photosynthesis. In collaboration with colleges in Norway, we plan to make use of a facility at Bergen University to perform femtosecond spectroscopy studies for the same purpose. Furthermore, experiments to determine kinetic

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energies of relevant fragments are planed to be performed by collaborators at the Technische Universitaet Braunschweig in Germany. The collaboration subproject are beneficial for all partners and will broaden our and the collaborators view and knowledge in fields of new techniques and theories.

b) Originality of the project is based on: 1) -Experimental determinations of photorupture channels and channel contributions by the

2D-REMPI. Apart from our first promising attempt along these lines of study this year[24] this method has not been used before by others. The 2D-REMPI analysis technique coupled with perturbation theoretical treatment to evaluate state interaction strengths and contributions to photorupture processes has been and is planed to be developed further within our research group. Briefly, ions formed by resonance enhanced multiphoton ionization (REMPI) are characterized and quantified as a function of laser excitation energy. The data are interpreted by quantum theoretical methods and simulations to derive information about photorupture channels and its contributions for chosen molecules. See text in frame below for further clarification / specific example.

Photorupture mechanism of HCl following resonance enhanced excitations to Rydberg states.

HCl

HCl*

HCl+

H+

E V

H+Cl+

H+Cl-

H + Cl* H* + Cl

Figure 5. Major photorupture channels for two-photon resonance enhanced excitations to Rydberg states. In figure 5 are shown major photorupture channels following two-photon resonance enhanced excitation to a Rydberg state[24-26, 28, 29]. Initially a Rydberg state (HCl*; Ry) is formed by two-photon excitation. HCl* can transfer to an ion-pair state (H+Cl-; V). Further photon absorption of (HCl*; Ry) can form HCl+ and H+, whereas H+ and Cl+ are the major ion products of further excitation of (H+Cl-; V) via H* + Cl and H + Cl* intermediates. Measurements of relative Cl+ and HCl+ ion formations allow determination of interaction strengths between the Rydberg state (Ry) and the ion-pair (V) state as well as relative contributions of the two states to the photorupture channels.

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2) – use of simulation programs for two- and three-photon REMPI spectra to characterize

energy properties of excited states involved. The model / program has been developed and is under continuous construction within the photochemistry research group in. U.I.

3) –combination of 2D-REMPI studies (in Iceland), femtosecond spectroscopic studies (in

Norway) and kinetic energy resolved studies (in Germany) in order to resolve photorupture mechanism of molecular systems of interest in fields related to ozone depletion, organic chemistry in interstellar space and photosynthesis.

4) –simultaneous search for new (i.e. not previously observed) electronic states of

molecules capable to be observed by multiphoton absorption only.

5) –the use of standard available ab initio methods (different levels and basis sets) rather then state-of-the-art work[48, 49] to explore properties of PES for electronically excited states of molecules and to carry the theoretical treatment a step further and evaluate spectrocopic constants to calculate “ab initio REMPI spectra” for comparison with the experimental data[24].

C. Research methodology, time plan and milestones. C. a) Research methodology. C.a. 1) Quantitative, qualitative and energy resolved analysis of radicals and ions formed by laser multiphoton absorption. i) High resolution REMPI-TOF measurements (see figure 6): Resonance enhanced multiphoton ionization (REMPI) of jet cooled gas is performed. Ions are directed into a time-of-flight tube and detected by a MCP detector to record the ion yield as a function of mass and laser radiation wavenumber to obtain two-dimensional REMPI (2D-REMPI) data. REMPI-TOF measurements in more detail: Tunable excitation radiation is generated using a Lambda Physik COMPex 205 Excimer laser, either with a Lumonics Hyperdye 300 or a Coherent ScanMatePro dye laser. Relevant dyes are used and frequency doubling obtained with BBO crystals. The repetition rate is typically 5 or 10 Hz. The bandwidth of the dye laser beam is about 0.05 – 0.10 cm-1 Typical laser intensity used is 0.2 mJ/pulse. The radiation is focused into an ionization chamber on a molecular beam between a repeller and extractor plates. Gas samples are pumped through a pulsed nozzle into the ionization chamber. Ions are extracted into a time-of-flight tube and focused onto a MCP detector, which signal is fed into a LeCroy 9310A, 400 MHz storage oscilloscope as a function of flight time. Average signal levels are evaluated and recorded for a fixed number of laser pulses to obtain mass spectra. The power dependence of the ion signal are determined by integrating the mass signals repeatedly and averaging over large number of laser pulses for different laser power.

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outoutout

Voltagedevider

HV-2Kv

HX nozzle

TurboPump

TOF

lense

MCP/iondetector

oscilloscope

computer

Excimer Laser

Inout

Dye-Laser

SHG

Timedelay

laser control

Pellin Brocaprism

SHG controlInInIn

REMPI-TOF

Laser beam

Figure 6. REMPI-TOF equipment.

ii) High resolution REMPI-current measurements (see figure 7): Procedure resembles that described above for REMPI-TOF measurements except instead of the use of a ionization chamber and a TOF mass spectrometer a static cell with gas samples at room temperature and low gas pressure is used. Ionization by means of laser pulses occurs between electrodes. Voltage drops across the electrodes are recorded as a function of absorbed photon energy to get 1D- REMPI spectra. REMPI-current measurements in more detail: Laser radiation is focused into an ionization cell between two stainless steel electrodes for recording REMPI-Current spectra. The electrodes are typically held at ± 200 - 300 voltages. The cell contains gas samples at low pressure, typically 1 - 5 Torr and room temperature. Current pulses in the gas due to laser pulse photoionization cause voltage drops across the electrodes. After amplification and integration the voltage pulses are fed into a LeCroy 9310A, 400MHz storage oscilloscope. Finally average voltage values for a fixed sampling time are recorded as a function of absorbed photon energy to get one-dimensional REMPI (1D-REMPI) spectra. Typically spectral points are obtained by averaging over 100 laser pulses.

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+

-

LASER beamLASER beam Figure 7. Schematic diagram for REMPI-current measurements.

C.a.2) Data from A(see above) are analyzed by use of simulation models developed within the research group at University of Iceland.

2D-REMPI-TOF data, such as shown below (Figure 8) for the HCl molecule, will be analyzed by simulation models to determine energy-properties of relevant excited states, coupling strengths between states and contributions of intermediate state to ion products[24], when relevant. These information form the basis for determining photorupture channels and photorupture mechanisms.

82833,6

82838,768

82842,88

82846,82857

82850,68

0,72

3624

1

1,32

098

33,1

081

34,8

49

36,6

345

38,4

646

40,3

393

-29967-28540-27113-25686-24259-22832-21405-19978-18551-17124-15697-14270-12843-11416-9989-8562-7135-5708-4281-2854-14270142728544281570871358562998911416128431427015697

2xhv

Mw /amu

35Cl+

37Cl+

H37Cl+

H35Cl+

H+

/cm-1

Figure 8. 2D-REMPI data for HCl

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C.a.3) Tracking Photorupture paths 1) by femtosecond laser spectroscopy at Bergen University and 2) by kinetic energy measurements of fragments in Germany.

i) femtosecond laser spectroscopy studies at Bergen University. Recently facility to perform femtosecond laser spectroscopy studies has been built within the physics department at Bergen University. The main device for the new laboratory is a state-of-the-art titanium sapphire tunable femtosecond laser from Coherent tunable in the visible and near Infrared spectral region. Furthermore, the laboratory holds a Nd:Yag pumped Dye laser system suitable to create nanosecond laser pulses in the visible region. These equipments are coupled to a gas sample holder and a field ionization detector suitable to measure high energy Rydberg states of atoms an molecules. The laboratory is headed by professor Öyvind Frette (femtosecond studies, optics[50] and experience in studies of ozone depletion[51]), Dr. Erik Horsdal Pedersen (field ionization studies and expert in analysis of Rydberg states of atoms[52]) and professor Jan Petter Hansen (head of physics dept.; research field: theoretical atom and molecular physics[53, 54]). These equipments as well as facility to perform laser frequency doubling will form the basis for our studies of photorupture channels by femtosecond spectroscopy. See more detailed description in the frame below. The basic principle of our experiment can by explained by reference to photorupture processes which are known to exist for acetylene[36]. See Figure 9:

Orka

HCCH:

HCCH*:HCCH*:C2 CH2C CH2C

H2

Stepwise photoexcitationby a ns laser pulse anda fs laser pulse

Excitation to Rydberg statesby fs laser pulses followed byfield ionization

C2C+

*CH2

+

Excitation to Rydberg states by fs laserpulses followed byfield ionization

Figure 9 Schematic Photorupture studies of acetylene by femtosecond laser spectroscopy

Initially, acetylene (HCCH) will be excited to a long-lived electronically excited state (HCCH*) by a ns laser pulse followed by a fs laser pulse excitation to a dissociative

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electronically excited state (HCCH**). Deformed molecular species (such as CCH2 or cis-C2H2; see figure 9) and/or fragments formed by dissociation (such as C2, H2, C and CH2 ; see figure 9) will be excited by delayed fs pulses to high energy (Rydberg) states followed by field ionization detection.

Photorupture studies by femtosecond laser spectroscopy in more detail: HCl as an example

180x103

160

140

120

100

80

E [c

m-1

]

4321r [Å]

H + Cl*(4P)

H + Cl*(2P)

H* + Cl

H + Cl+

H+ + ClX(HCl

+)2Π

HCl**

F(HCl*)1∆ V(H+Cl

-)1Σ

H + Cl*

ns laser pulse excitation

fs laser pulse excitation

field ionization

fs delayed laser pulse excitation

HCl*(Ry) (Ry)

Figure 10. Energetic for HCl relevant to femtosecond studies of photorupture channels.

HCl gas will be ejected into a gas sample chamber. HCl molecules will be excited to the F1∆, v´= 0 Rydberg state by two-photon excitation using frequency doubled nanosecond pulses from a Nd:Yag pumped Dye laser. F1∆, v´= 0, Rydberg state molecules will be excited by femtosecond laser pulses in the visible or near infrared region to a highly excited Rydberg state, which is known to couple to the V1Σ+ ion-pair state, hence to cause the molecule to transfer to the ion-pair state and to cause the atoms to move apart. This process will be followed by two-photon excitations of the HCl*(Ry)/H+Cl- (ion-pair) species to a highly excited repulsive HCl** state to form Cl* which can be detected by field ionization. Furthermore, disappearance of the HCl*(Ry) species can be followed by field ionization detection of those species with time delayed field ionization pulses. ii) Kinetic energy measurements of fragments in Germany. The research group at the Technische Universitat Braunschweig in Germany headed by prof. Christof Maul uses REMPI/TOF delay-line detectors (DLD) equipment (see figure 11 and ref. [43]) to record 3D images of ion intensities as a function of distances from the center of a microchannel plate (MCP) /ion detector in the time of flight (TOF) mass spectrometer. This allows derivations of kinetic energies for ions formed by photorupture channels. Such data (see figure 12) along with the above mentioned experimental data are very important to characterize photorupture channels in detail.

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Figure 11. A schematic REMPI/TOF/DLD 3D imaging experimental setup at Technische Universitat Braunschweig. (see ref. [43] )

H+ kinetic energy

H+

inte

nsity

Figure 12. Proton image following (2+n) REMPI of HCl using the REMPI/TOF/DLD 3D imaging technique (from ref. [28] )

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Photorupture studies by kinetic energy measurements of fragments in Germany in more detail; HCl as an example: The first project to be performed along these lines in collaboration with prof. C. Mauls research group at the Technische Universitat Braunschweig is based on our observations made for photorupture channels via excitations to the F1∆, v´= 1 states[24]. Rotational quantum level, J´=8 in F1∆, v´= 1 is found to couple strongly to the V1Σ+, v´=14, J´=8 state whereas insignificant coupling is observed for other J´ states. This shows as dramatic difference in ion product species formations. The REMPI/TOF/DLD 3D imaging equipment at Braunschweig (see figure 11, above) will be used to derive kinetic energy data for the ion species H+, Cl+ and HCl+ for two-photon excitations to different J´ levels in F1∆, v´= 1. The data will be used to derive quantitative and qualitative information relevant to photorupture channels following interaction between the F1∆ Rydberg state and the V1Σ+ ion-pair state.

C.a.4) Ab initio spectroscopic parameters and REMPI spectra:

Ab initio calculations at several levels with a number of basis sets will be performed to study the potential energy surfaces belonging to Rydberg states of small molecules relevant to the above mentioned studies. The vibrational and the rotational spectroscopic parameters can be evaluated by solving the nuclear Schrödinger equation on a fit potential surface based on ab initio energies with numerical methods, e.g. the Fourier Grid Hamiltonian[55]. Based on the calculated spectroscopic paremeters, the theoretical two-photon absorption spectra can be calculated. This approach serves the double purpose of helping with the interpretation of experimental photorupture data as mentioned above and to act as a guiding tool for making plans about experiments. This work will be headed by Dr. Andras Bodi at the Paul Scherrer Institut, Villigen in Switzerland and professor Ingvar Árnason, University of Iceland [56-59]. Recently, we published a paper including our first attempt to calculate spectroscopic parameters and ab initio REMPI spectra for HCl[24]. Slight but significant improvements in the calculations compared to older calculations[49] were obtained. Our major contribution in this work was to take the theory to the next level, and directly compare experimental results with theoretical predictions. In doing so, we have employed single-reference methods to calculate excitation energies, e.g. equation-of-motion coupled cluster singles and doubles[60] or a renormalized, CR-EOM-CCSD(T)[61] approach. These “out-of-the-box” methods were able to deliver slightly better results than previous multireference calculations[49]. However, in order to come close to experimental accuracy for simple systems, or to make reliable predictions for more complex ones, a multireference (MR) approach is needed in order to describe static electron correlation effects, such as MR-CI[62, 63] or MR-CC[64]. Additionally, explicit consideration of relativistic corrections and spin-orbit coupling[65] may also be necessary to reach the desired accuracy. Ab initio REMPI spectra calculations in more detail: Calculating Rydberg potential energy surfaces (PES) has two aims. First, the excitation energy and the rotational constants are known from experiment. By comparing these with the calculated results, the methods and basis sets are actually benchmarked. Second, if computational methods are found that reproduce the experiment reasonably well, it is worthwhile to try modeling the ensuing photodissociation-photoionization processes with them. Single reference coupled cluster methods (EOM-CC and CR-CC) are being used in our group to study the potential energy surfaces belonging to Rydberg states of small molecules. Correlation-consistent Dunning-type basis sets are used (aug-cc-pVXZ, X=T,Q,5...) in order to be able to systematically improve the wavefunction

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flexibility. Nevertheless, these basis sets are occasionally further augmented with diffuse functions to improve their quality in the Rydberg space. Test calculations are also carried out with time-dependent DFT (TDFT). The program packages employed are Gaussian03 (TDFT), ACES-II (EOM-CC), and/or NWChem (EOM-CC, CR-CC). By using the NorduGrid network, which HI has recently acquired, the plan is also to perform multi-reference calculations (MR-CI) using the program package Molpro. Following either Morse potential or spline fits to the ab initioPES average internuclear distances (re / Å), dissociation energies (De / cm

-1), vibrational frequencies (ωe / cm-1), anharmonicity parameters (ωexe / cm-1) and the rotational parameter Be (cm

-1) are determined. These parameters coupled with quantum theoretical formalism for multiphoton transition strengths[66] allow ab initio REMPI spectra to be predicted.

C.b) Project plan: Research work along the lines as described above (A-D) will be performed for four major groups of chemical compounds:

I. Hydrogen halides, HX; X = Cl, Br, I II. Halogens, X2; X = Cl, I III. Small organic compounds, CxHy IV. Small chlorine containing organic compounds, CxHyCl as:

chemicals: Project:

Hydrogen halides/ HX; X = Cl, Br, I

Halogens / X2; X = Cl, I

Organic compounds / CxHy

Chlorine containing organic compounds / CxHyCl

A/ REMPI experiments

X= Cl, Br, I

(2+n) & (3+m) REMPI 1)

X = Cl, I; (3+m) REMPI2)

CH4;C2H6 C2H4; (2+n) REMPI3)

CH3Cl; (2+n) REMPI3)

B/ REMPI analysis and simulations

Simulations, photorupture analysis

Simulations photorupture analysis

photorupture analysis

photorupture analysis

C. 1) Femtosecond spectroscopy, 2) kinetic energy measurements

X=Cl C2H2

D/ ab initio calculations

X=Cl X=Cl CH4

1) Both two- and three-photon resonance enhanced excitations / i.e. (2+n) and (3+m)

REMPI. 2) Emphasis laid on three-photon resonance enhanced excitations (i.e. (3+m)REMPI)

which has very limited been performed for the halogens. 3) Emphasis laid on two-photon resonance enhanced excitations (i.e. (2+n)REMPI).

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C.c) Time plan and project emphasis:

2009 2010 2011 Weight/ % 1)

A / REMPI measurements HX X2 CxHy CH3Cl 25

B / REMPI analysis HX X2 CxHy 30

C / 1) femtosecond spectroscopy2) Kinetic energy analysis

HCl CH4 /C2H2 15

D / ab initio calculations HCl CH4 / C2H2 15

E / presentations (publications etc.)

HX X2 15

yearProjects:

CH4

CH4

CxHy

1) only to be viewed as a rough estimate for manpower in the project

D. Co-operation (foreign and domestic) and collaborators contributions:

Collabor-ators:

A/ REMPI measure-ments

B/ REMPI analysis

C 1./ fs- spectro-scopy

C 2./ kinetic energy exp.

D / ab initio calculat-ions

E / present-ations; publ-ications

In Iceland: Victor Huasheng Wang; Research scientist, U.I.

Leading experiments, student advisor and performs experiments

Simulations and data analysis

Scientific paper writing, conference presentations

Kristján Matthíasson, PhD student, U.I.

student advisor, performs experiments

Simulations, data analysis and detailed interpretat-ions; student advisor

Experimental work and analysis

Scientific paper writing, conference presentations, PhD Thesis

Arnar Hafliðason, MS student, U.I.

performs experiments



Data analysis

conference presentations; Thesis, contributions to scientific paper writing.

Andreas Piekarczyk, ERASMUS /undergradute student from Freiburg, Germany

performs experiments under supervision

Simulations and data analysis under supervision

BS thesis

Ingvar Árnason, professor in chemistry U.I.

Consultation and student advisor

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Collabor-ators:

A/ REMPI measure-ments

B/ REMPI analysis





abroad: Frette Øyvind 1), Professor, Dept. of Physics, University of Bergen



Erik Horsdal2), lektor, Dept. of Physics, University of Aarhus and Bergen



Jan Petter Hansen3), professor, Dept. of Physics, University of Bergen


Christof Maul, professor, Technische Universitat Braunschweig, Germany



Andras Bodi, postdoctor, Paul Scherrer Institut, Villigen, Switzerland4)

Consultation, student advisor and performs calculations


1) Öyvind Frette: femtosecond studies, optics[50] and experience in studies of ozone

depletion[51]. 2) Dr. Erik Horsdal Pedersen: field ionization studies and expert in analysis of Rydberg

states of atoms[52] 3) Jan Petter Hansen: head of physics dept.; research field: theoretical atom and

molecular physics[53, 54] 4) Aims to move to Iceland in 2009, temporarily(?)

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E. Gradute student contributions (partly repeted above).

D-E. Estimated contributions in terms of manpower / man-month (mm) input (see also “C. Detailed budget and justification of cost for the duration of the project.”)

Students: A/ REMPI measurements

B/ REMPI analysis





Kristján Matthíasson, PhD student, U.I.

student advisor and performs experiments



Scientific paper writing, conference presentations, PhD Thesis

Arnar Hafliðason, MS student, U.I.




Data analysis conference presentations; Thesis, contributions to scientific paper writing.

N1.N1., PhD student, U.I.

student advisor and performs experiments



performs calculations

Scientific paper writing, conference presentations; PhD Thesis

N2.N2., MS student, U.I.




performs calculations

conference presentations; MS Thesis, contributions to scientific paper writing.

Year: 2009 2010 2011

Particiants: Months work

Months work

Months work

mm mm mm Victor H. Wang 10 10 10 Kristján Matthíasson(PhD) 10 0 0 Arnar Hafliðason (MS) 7 10 5 N1.N1. (PhD) 4 10 10 N2.N2.(MS) 0 4 10 Ingvar Helgi Árnason, prof. U.I. 0.5 0.5 0.5 Frette Øyvind 0.3 0.5 0.5 Erik Horsdal Pedersen 0.3 0.5 0.5 Jan Petter Hansen 0 0.2 0.2 Christof Maul 0.3 0.3 0.3 Andras Bode 2 2 2 Ágúst Kvaran 3 3 3 Total mm 37.4 41 42

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F. Proposed deliverables and impacts. Various deliverables are to be expected as a result of the project. 1. Knowledge-related benefits of the project: The project will result in additional basic knowledge relevant to photorupture processes within molecules for compounds of importance in fields of a) -atmospheric photochemistry, b) – photoproduction processes of organic molecules in interstellar space and c) – photosynthesis. Such deliverables are according to the ideology of basic academic research, such as “In order to be able to make maximum use of material properties for applied purposes a complete understanding of its nature is vital.” 2. Environmental benefits: The project deals to large extend with studies of photorupture processes in small gaseous chlorine containing reagents which are of importance in the photochemistry of the atmosphere and ozone depletion. Hence, results from the project will add to our knowledge of environmentally important processes in the atmosphere. Various impacts of the research projects are to be expected, such as:

1) Scientific papers: the three years research project, as planned, is expected to result in scientific publications in international journals (say 3 to 5 papers) based on previous experience. Emphasis will be laid on publications in highly cited (high impact factor) journals.

2) Academic degrees: According to the plan, significant amount of the scientific work for the three years project will be performed by students aiming for academic degrees (MS and PhD). 2 to 4 academic degrees are to be expected.

3) Thesis: The work performed by the students aiming for academic degrees will result in thesis including mored eitailed results than to be found in scientific publications. Smaller subprojects carried out by undergraduates also will result in thesis.

4) New or improved methodology: The project involves use of a experimental technique different from that used by others, i.e. use of mass spectrometer analysis of ions formed by multiphoton absorption and simulation analysis developed in Iceland in order to study photorupture processes in molecules. Hence the project will result in new and improved methodology.

5) A varification of a scientific statement: A statement has been made that mass spectrometer analysis following multiphoton ionization as a function of excitation energy coupled with use of quantum chemical simulation analysis techniques can be use to identify and quantify photorupture channels in molecules. This waits to be approved.

6) Simulation model and relevant computer program: The project involves development of models and relevant computer programs for simulating data obtained from resonance enhanced multiphoton ionization data.

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G. Proposed publications of results: As clearly seen by the applicants presentation- and publication- lists emphasis has been laid on oral and written presentations of research results in the past. This will continue:

1. Papers will be published in international scientific journals. Emphasis will be laid on publications in highly cited (high impact factor) journals. Our first results on photorupture channels already have been / will be publish in Chem. Phys. Lett.[36] and J. Chem. Phys.[24] , 2008.

2. Oral presentations will be given at international and domestic conferences. 3. Written presentations will be published at conference proceedings, when

relevant. 4. Abstracts, relevant to presentations at conferences will be distributed. 5. Poster presentations will be given at international conferences. 6. Oral presentations will be given at research institutes. 7. Useful thesis writing and clear presentations by students will be emphasized. 8. Public presentations about research emphasizes and methodology will be

given. References: 1. Solomon, S., Stratospheric ozone depletion: A review of concepts and history.

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60: p. 127-134. 3. Basic chemistry of ozone depletion;

http://www.nas.nasa.gov/About/Education/Ozone/chemistry.html. 2007. 4. Huasheng, W., et al., Rotationally resolved (2+1) REMPI spectra of gerade Rydberg

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10. Kvaran, Á., H. Wang, and G.H. Jóhannesson, REMPI spectra of IBr: Vibrational and rotational analysis of the b[2Π1/2] c6s;1 Rydberg states of I79Br and I81Br. J.Phys.Chem., 1995. 99(13): p. 4451-4457.

11. Jóhannesson, G.H., H. Wang, and Á. Kvaran, REMPI Spectra of Cl2: Vibrational and Rotational Analysis of the 21Πg Rydberg State of 35Cl2, 35Cl37Cl, and 37Cl2. J. Molecular Spectroscopy, 1996. 179: p. 334-341.

12. Kvaran, Á., G.H. Jóhannesson, and H. Wang, Rotational perturbations in the (2+1) REMPI spectrum of the Rydberg state [2Π3/2] c5d;1g of I2. Chem. Physics, 1996. 204: p. 65-75.

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15. Kvaran, Á., B.G. Waage, and H. Wang, What to see and what not to see in 3 photon absorption: (3+1)REMPI of HBr. J. Chem. Phys., 2000. 113(5): p. 1755-1761.

16. Kvaran, Á., H. Wang, and Á. Logadóttir, Resonance enhanced multiphoton ionization of the hydrogen halides; Rotational structure and anomalies in Rydberg and ion-pair states of HCl and HBr. J. Chem. Phys., 2000. 112(24): p. 10811-10820.

17. Kvaran, Á., H. Wang, and B.G. Waage, Three- and two-photon absorption spectroscopy: REMPI of HCl and HBr. Can. J. Physics, 2001. 79: p. 197-210.

18. Wang, H. and Á. Kvaran, Three-photon absorption spectroscopy: (3+1)REMPI of HCl (I1∆(2)-X1Σ(0+)). J. of Molec. Structure, 2001. 563-564: p. 235-239.

19. Kvaran, Á. and H. Wang, Three-photon Absorption Spectroscopy: The L(1Φ3) and m(3Π1) States of HCl and DCl. Molec. Phys., 2002. 100(22): p. 3513-3519.

20. Kvaran, Á. and H. Wang, Three- and two- photon absorption in HCl and DCl: identification of Ω = 3 states and state interaction analysis. J. Mol. Spectrosc., 2004. 228(1): p. 143-151.

21. Kvaran, Á., K. Matthíasson, and H. Wang, Three-Photon Absorption Of Open Shell Structured Molecules; (3+1) REMPI of NO As A Case Study. Physical Chemistry; An Indian Journal, 2006. 1(1): p. 11-25.

22. Kvaran, Á., Ó.F. Sigurbjörnsson, and H. Wang, REMPI-TOF studies of the HF dimer. J. Mol. Struct., 2006. 790: p. 27-30.

23. Wang, H. and Á. Kvaran, REMPI spectra of the hydrogen halides. Acta Physico-Chimica Sinica; http://www.whxb.pku.edu.cn/en/zxly.asp 2007.

24. Kvaran, Á., et al., Two Dimensional (2+n) Resonance Enhanced MultiPhoton Ionization of HCl: Photorupture Channels via the F 1D2 Rydberg State and ab initio Spectra J. Chem. Phys. (accepted for publication), 2008. 129(17): p.?

25. Chichinin, A.I., C. Maul, and K.H. Gericke, Photoionization and photodissociation of HCl(B 1Σ+, J=0) near 236 and 239 nm using three-dimensional ion imaging. J. Chem. Phys., 2006. 124(22): p. 224324.

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