benzocoronene and it’s derivatives: a look at supramolecular electronics€¦ · supramolecular...

Benzocoronene Derivatives: A Look at Supramolecular

Electronics

Karrie M. ManesOrganic Seminar25 October 2006

Michigan State UniversityEast Lansing, MI 48823

OutlineWhat are supramolecular electronics?

Background

BenzocoroneneSynthesisCharacterizationElectrical propertiesWhat affects electronic properties?Application-Driven Assemblies

What is Supramolecular Electronics?

UnimolecularElectronics

SupramolecularElectronics

PlasticElectronics

S S Gate

Electrode Electrode Electrode ElectrodeSource

ConjugatedPolymer Drain

Angstroms MicrometersNanometersDimensions

5 – 100 nm

Schenning, A.PH.J.; Meijer, E.W. Chem. Comm., 2005, 3245-3258.

Supramolecular Interactions

Non-covalent interactionsHydrogen bondingHydrophobic forcesvan der Waals forcesMetal coordinationπ-π interactions

Host-guest chemistry, self-assembly & molecular recognitionImportance recognized in 1987 when Nobel Prize in Chemistry awarded to Cram, Lehn & Pederson for work in this area

π-π Stacking

A stacked arrangement of aromatic molecules which interact through van der WaalsforcesEdge-to-face and face-to-face

http://en.wikipedia.org/wiki/DNA

http://en.wikipedia.org/wiki/Image:DNA_Overview.png

What makes a good organic semi-conductor?

AnisotropyStructural regularityHigh charge carrier mobilityEase of synthesisStabilityCost effectiveScalable to high-production volumesEasily processed into electronic devices

What Kind of Devices

Field EffectTransistors

PhotovoltaicCells

Pictures courtesy of www.wikipedia.com

http://en.wikipedia.org/wiki/Image:Solar_cell.png

http://en.wikipedia.org/wiki/Image:P45N02LD.jpg

A Standard Diode

How Stuff Works. http://electronics.howstuffworks.com/led1.htm (accessed 15 October 2006)

http://electronics.howstuffworks.com/led1.htm

Unimolecular Electronics



PlasticElectronics

S S Gate




5 – 100 nm

Unimolecular ElectronicsNC CN

CNNC

S S

S S

NC

NC

CN

CNACCEPTOR: TCNQ (tetracyanoquinodimethane)

S

SS

SDONOR: TTF (tetrathiafulvalene)

Ratner, M.A.; Chem. Phys. Let., 1974, 29, 277-283.

Unimolecular ElectronicsCNNC

e-

NC CN

CNNC

NC CN

Easily reducedby one electron

S S

SSe-

S S

SSEasily oxidizedby one electron

TTF + TCNQ TTF + TCNQ

Unimolecular Electronics

Cathode Anode

e-

NC

NC CN

CN

S

S

S

S

Molecular Rectifier

Metal

Acceptor Donor

V = 0Molecule Metal

π1φ π2Internal

Tunneling

Barrier(σ-bonds)

Ratner, M.A.; Chem. Phys. Let., 1974, 29, 277-283.

Plastic Electronics



PlasticElectronics

S S Gate




5 – 100 nm

Plastic Electronics

n

Most popular commercially available conducting polymerCapable of electroluminescence (use in LEDs)Sensitive to presence of oxygenCharge carrier mobility <10-5 cm2/Vs (σ=10-13

S/cm)

PPV (Poly(p-phenylene vinylene)

Handbook of Conducting Polymers, 2nd Ed.; Skotheim, T.A.; Elsenaumer, R.L; Reynolds, J.R. Eds.;Marcel Dekker, Inc.: New York, NY, 1995, p.353.

MEH-PPV

n

OMe

O

Plastic ElectronicsDoping of PPV can change conductivityPPV properties can be varied over a wide range by inclusion of functional side groups

Aromatic, alkoxy, alkyl, silyl, halogen, sulfur, amino

Dopant Conductivity(S/cm)

FeCl3 (0.071 equiv) 35

FeCl3 (0.39 equiv) 230

Na Naphthalide 2 x 10-4

AsF5 10H2SO4 2700

I2 <10-3

Handbook of Conducting Polymers, 2nd Ed.; Skotheim, T.A.; Elsenaumer, R.L; Reynolds, J.R. Eds.;Marcel Dekker, Inc.: New York, NY, 1995, p.353.

Supramolecular Electronics



PlasticElectronics

S S Gate




5 – 100 nm

BenzocoronenesR

R

R

R

R

R

R = H: Hexa-peri-hexabenzocoronene42 C atoms in 13 adjoining C6 memberedringsPlanarDisc-shapedDiameter = 15ÅConsidered an oligomeric version of an infinite 2-D graphite sheet

Brand, J.D.; Geerts, Y.; Mullen, K.; van de Craats, A.M.; Warman, J.M. Adv. Mater., 1998, 10, 36-38.

Benzocoronenes

Self-Assemble inherringbone pattern

Upon heating producesorthogonal intracolumnar

packing

R

R

R

R

R

R

Simpson, C.D.; Wu, J.; Watson, M.D.; Mullen, K. J. .Mater. Chem., 2004, 14, 494-504.Brand, J.D.; Geerts, Y.; Mullen, K.; van de Craats, A.M.; Warman, J.M. Adv. Mater., 1998, 10, 36-38.

GraphiteConductivity along plane of layer ~1000 S/cmConductivity perpendicular to plane of layer ~250 S/cm Cu = ~6x105 S/cmair = ~2.5-5 x10-12 S/cmCharge carrier mobility perpendicular to plane ~3 cm2/VsLow doped Si = ~1350 cm2/Vs

NDT Resource Center.http://www.ndt-ed.org/GeneralResources/MaterialProperties/ET/ET_matlprop_Misc_Matls.htm(accessed 2 October 2006).

Neamen, D. An Introduction to Semiconductor Devices. McGraw-Hill: New York, NY, 2006; pp.131Simon Fraser Unviersity – Automated Design for Micromatching. http://www.sfu.ca/adm/capacitor.html

http://www.ndt-ed.org/GeneralResources/MaterialProperties/ET/ET_matlprop_Misc_Matls.htm

http://en.wikipedia.org/wiki/Image:Graphit_gitter.png

BenzocoronenesHow are they synthesized?

How is their discotic liquid crystal phase characterized?

How are electrical properties measured?What factors affect them?

SynthesisCore size

Application-driven assemblies

Synthesis of Alkyne Precursor

BrBr

NiCl2(dppp),RMgBr RR

CCl4, RT

RR

Br

Br

tBuOH, tBuO-K+

RR

Et2O

92%

90%

69%

Br2

reflux

Ito, S.; Wehmeier, M.; Brand, J.D.; Kubel, C.; Epsch, R.; Rabe, J.P.; Mullen, K., Chem. Eur. J., 2000, 6, 4327-4342.

Synthesis of Benzocoronene

RR

R

R

R

R

R

R

AlCl3,Cu(OSO2CF3)2,

R

R

R

R

R

R

Co2(CO)8

92%

49%

dioxane, ref lux

CS2, RT


R = dodecyl

Synthesis – Selective FunctionalizationCH2Br

X

RR

Fe(CO)5, KOH,benzyltriethyl-ammonium chloride,

DMSO,155°C

O

XX

OO

KOH, EtOH,reflux, 5 min

OX

X

R R

R R

47-53%69%

43-60%

I2CH2Cl2,H2O, reflux


R = dodecylX = Br or dodecyl

Synthesis – Selective Functionalization

Br R

PdCl2(PPh3)2, CuI,PPh3, piperidine,TMS-acetylene

RTMS

THF,RT

R

PdCl2(PPh3)2, CuI,PPh3, piperidine,4-bromo-iodobenzeneRBr

89%

95%

74%

65°C

65°C

KF

R = dodecyl



OX

X

R R

RBr+

diphenylether, reflux-CO

Br

R

X

R

R

X

71-76%

R = dodecylX = Br or docecyl



Br

R

X

R

R

X

Br

R

X

R

R

X

FeCl3, CH3NO2

87-93%

CH2Cl2, RT

R = dodecylX = Br or docecyl

Ito, S.; Wehmeier, M.; Brand, J.D.; Kubel, C.; Epscah, R.; Rabe, J.P.; Mullen, K., Chem. Eur. J., 2000, 6, 4327-4342.




SynthesisCore size


Characterization

Differential Scanning Calorimetry (DSC)

Polarizing Light Microscopy

X-Ray Diffraction (XRD)

Scanning Tunneling Microscopy (STM)

LC Phase Characterization -DSC

C12H25

C12H25

C12H25

C12H25

C12H25

C12H25

H

C14H29

C14H29

C14H29

C14H29

C14H29

Solids at room tempExhibit a liquid crystalline phase at elevated temperatures (106.5˚C & 124.4˚C)Form single liquid crystal phase over broad temperature range (up to ~400˚C)


LC Phase Characterization – Optical Microscopy

408˚C - Heating 380˚C - Cooling

Textures typical for a columnar liquid crystal phase


LC Phase Characterization – XRD

Br

Br

C10H21

C10H21

C10H21

C10H21

Indicates periodic stacking of aromatic coresHalo associated to liquid-like correlation between aliphatic chains


LC Phase Characterization – STM

Penta-alkyl substituted HBC showed two molecular patternsDimer and rhombic lattice


H

C14H29

C14H29

C14H29

C14H29

C14H29




SynthesisCore size


How Are Electrical Properties Measured?

PR-TRMC – Pulse Radiolysis Time-Resolved Microwave Conductivity

Uses high energy electrons as irradiation sourceIf charge carriers created are mobile there is an increase in conductivityDoes not use electrodes

Warman, J.M.; de Haas, M.P.; Dicker, G.; Grozema, F.C.; Piris, J.; Debije, M.G. Chem. Mater., 2004, 16, 4600-4609.

How Are Electrical Properties Measured?

Time of Flight MethodSample is illuminated with Nd:YAG laserCarrier type is selected by applying a biasCurrent transient formed by laser pulse and applied field recorded on an oscilloscopeMobilities calculated using:

trd/Et = µ d = thickness of filmE = applied fieldttr = charge carrier transit time

Lehigh University. http://www.lehigh.edu/~inlo/htof.html (accessed 21 October 2006)

http://www.lehigh.edu/~inlo/htof.html

Characteristics that May Effect Electrical Properties

SynthesisDoes the method we use to synthesize these rings matter?

Core SizeWill increasing core size increase charge carrier mobility?

SynthesisC14H29

C14H29

C14H29

C14H29

C14H29

C14H29~65˚C

Hea

t Flo

w fr

om s

ampl

e

Brand, J.D.; Geerts, Y.; Mullen, K.; van de Craats, A.M.; Warman, J.M. Adv. Mater., 1998, 10, 36-38.

Synthesis

C14H29

C14H29

C14H29

C14H29

C14H29

C14H29Route 1:AlCl3, Cu(OSO2CF3)2,CS2, RT

C14H29

C14H29

C14H29

C14H29

C14H29

C14H29

Route 2:FeCl3, CH3NO2, CH2Cl2

Brand, J.D.; Geerts, Y.; Mullen, K.; van de Craats, A.M.; Warman, J.M. Adv. Mater., 1998, 10, 36-38.Brand, J.D.; Mullen, K.; Harbison, M.A.; Fechtenkotter, A.; van de Craats, A.M.; Warman, J.M. Adv Mater., 1999, 11, 1469-1471.

Synthesis

Route 1

Cha

rge

Car

rier M

obili

ty (c

m2 /V

s)

Route 2

Charge carrier mobility = 0.13 cm2/Vs Charge carrier mobility = 0.31 cm2/Vs

Brand, J.D.; Geerts, Y.; Mullen, K.; van de Craats, A.M.; Warman, J.M. Adv. Mater., 1998, 10, 36-38.Brand, J.D.; Mullen, K.; Harbison, M.A.; Fechtenkotter, A.; van de Craats, A.M.; Warman, J.M. Adv Mater., 1999, 11, 1469-1471.

An Unexpected ResultA room temperaturediscotic liquid crystal!

Cha

rge

Car

rier M

obili

ty (c

m2 /V

s)

C12H25

C12H25

C12H25

C12H25

C12H25

C12H25

Charge carrier mobility at RT = 0.22 cm2/Vs

Brand, J.D.; Mullen, K.; Harbison, M.A.; Fechtenkotter, A.; van de Craats, A.M.; Warman, J.M. Adv Mater., 1999, 11, 1469-1471.

Characteristics that May Effect Electrical Properties

SynthesisDoes the method we use to synthesize these rings matter?

Core SizeWill increasing core size increase charge carrier mobility?

Core SizeR

R

R

R

R

R

R

R

R

R

R

R

R

R

R

R

R

R

R R R

R

RRR

R

R =

Ar24Ar42

Ar60Ar96

C12

Debije, M.G.; Piris, J.; de Haas, M.P.; Tomovic, Z.; Simpson, C.D.; Watson, M.D.; Mullen, K.; Warman, J.M., J. Am. Chem. Soc., 2004, 126, 4641-4645.

Core Size

µ = 0.10-0.20 cm2/Vs µ = 0.26 cm2/Vs

µ = 0.38 cm2/Vs

µ = 0.20 cm2/Vs

van de Craats, A.M.; Warman, J.M. Adv. Mater., 2001, 13, 130-133.Debije, M.G.; Piris, J.; de Haas, M.P.; Tomovic, Z.; Simpson, C.D.; Watson, M.D.; Mullen, K.; Warman, J.M., J. Am. Chem. Soc., 2004, 126, 4641-4645.




SynthesisCore size


How Would Devices Be Built?

Simpson, C.D.; Wu, J.; Watson, M.D.; Mullen, K. J. .Mater. Chem., 2004, 14, 494-504.

OO

O

OO

O

R

R

Application-Driven Assemblies –Graphitic Nanotubes

S

R = H or CH3

AmphiphilicAnalogous to carbon nanotubesControl packing through solvent composition

Aida, T.; Ishii, N.; Hashizume, T.; Ito, K.; Shimomura, T.; Ichihara, H.; Fukushima, T.; Kosaka, A.; Jin, W.; Hill, J.,Science, 2004, 304, 1481-1483.Aida, T.; Tagawa, S., Seki, S.; Saeki, A.; Nakamura, T.; Hara, T.; Kosaka, A.; Jin, W.; Fukushima, T.;Yamamoto, Y. Adv. Mater., 2006, 18, 1297-1300.


TEM of diluted samples in THF

200nm 50nm

TEM of diluted samples in a 20% v/v THF/H2O mixture

200nm 50nm

SEM of solid

Aida, T.; Ishii, N.; Hashizume, T.; Ito, K.; Shimomura, T.; Ichihara, H.; Fukushima, T.; Kosaka, A.; Jin, W.; Hill, J.,Science, 2004, 304, 1481-1483.


Con

duct

ivity

x 1

0-9

(Ωcm

)

Tube placed along a 180 nm Pt nanogap

Aida, T.; Ishii, N.; Hashizume, T.; Ito, K.; Shimomura, T.; Ichihara, H.; Fukushima, T.; Kosaka, A.; Jin, W.; Hill, J.,Science, 2004, 304, 1481-1483.


O

O

O

O

O

O

H3C CH3

GlassHook

Fiber

Suspension of ‘S’ nanotubes Macroscopic fiber“fished” out with a glass hook

Aida, T.; Tagawa, S., Seki, S.; Saeki, A.; Nakamura, T.; Hara, T.; Kosaka, A.; Jin, W.; Fukushima, T.;Yamamoto, Y. Adv. Mater., 2006, 18, 1297-1300.


Polarized optical microscopy suggests thatnanotube bundles oriented unidirectionallyalong fiber axis



Fibers doped with I2ESR indicates generation of radical species as charge carriersResistivity decreases with temperature

Resistivity betweenfibers

Resistivity alongfiber axis



Con

duct

ivity

x 1

0-8

(S/c

m)

Conductivity alongfiber axis

Conductivity betweenfibers

Conductivities observed parallel and perpendicular to the fiber axis


C12H25

C12H25

C12H25

C12H25

C12H25

C12H25

Application-Driven Assemblies - Photovoltaics

N N

O

O O

O

Dicarboximide-perylene

HBC- PhC12MacKenzie, J.D.; Friend, R.H.; Moons, E.; Fechtenkotter, A.; Schmidt-Mende, L.; Mullen, K. Science, 2001,293, 1119-1122.


AFM of HBC – PhC12AFM of Dicarboximide-perylene

MacKenzie, J.D.; Friend, R.H.; Moons, E.; Fechtenkotter, A.; Schmidt-Mende, L.; Mullen, K. Science, 2001,293, 1119-1122.


Dicarboximide-perylene

HBC-PhC12SEM of ~50/50 mixture HBC-PhC12-Perylene blend spin-coated on Si substrate

AFM of HBC-PhC12 – PeryleneBlend



PhotovoltaicDevice

HBC-PhC12

Perylene

40:60 HBC-PhC12:Perylene Blend

490 nm

Photovoltaic device made with HBC-PhC12-Perylene blend between Al and ITO plates


Future Work

More work on adding EWG or EDG on periphery

Find ways to try and control the pi-stacking in order to increase conductivity

Make actual FET or other devices and see how they respond over longer periods of time

Thoughts and Outlook

Benzocoronene derivatives may be viable option for further miniaturization of electronic devices

Electronic properties should be improved upon if these systems are to compete with current technology

Many aspects of these systems is still unknownAre these systems robust enough?Can these systems be processed on a large scale?Will the scale-up of these systems be cost prohibitive?

Do electronic devices really need to be any smaller than they already are?

Acknowledgements

Dr. JacksonDr. BakerDr. WulffDr. SmithJackson Group: Jen, Simona, Misha, Partha& DustonToyin, Brian, Monica, Aman D.

benzocoronene and it’s derivatives: a look at supramolecular electronics€¦ · supramolecular...

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