Benzocoronene and It’s Derivatives: A Look at Supramolecular Electronics€¦ · Supramolecular...
Transcript of 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
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
A Standard Diode
How Stuff Works. http://electronics.howstuffworks.com/led1.htm (accessed 15 October 2006)
Unimolecular Electronics
UnimolecularElectronics
SupramolecularElectronics
PlasticElectronics
S S Gate
Electrode Electrode Electrode ElectrodeSource
ConjugatedPolymer Drain
Angstroms MicrometersNanometersDimensions
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
UnimolecularElectronics
SupramolecularElectronics
PlasticElectronics
S S Gate
Electrode Electrode Electrode ElectrodeSource
ConjugatedPolymer Drain
Angstroms MicrometersNanometersDimensions
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
UnimolecularElectronics
SupramolecularElectronics
PlasticElectronics
S S Gate
Electrode Electrode Electrode ElectrodeSource
ConjugatedPolymer Drain
Angstroms MicrometersNanometersDimensions
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
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
Ito, S.; Wehmeier, M.; Brand, J.D.; Kubel, C.; Epsch, R.; Rabe, J.P.; Mullen, K., Chem. Eur. J., 2000, 6, 4327-4342.
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
Ito, S.; Wehmeier, M.; Brand, J.D.; Kubel, C.; Epsch, R.; Rabe, J.P.; Mullen, K., Chem. Eur. J., 2000, 6, 4327-4342.
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
Ito, S.; Wehmeier, M.; Brand, J.D.; Kubel, C.; Epsch, R.; Rabe, J.P.; Mullen, K., Chem. Eur. J., 2000, 6, 4327-4342.
Synthesis – Selective Functionalization
OX
X
R R
RBr+
diphenylether, reflux-CO
Br
R
X
R
R
X
71-76%
R = dodecylX = Br or docecyl
Ito, S.; Wehmeier, M.; Brand, J.D.; Kubel, C.; Epsch, R.; Rabe, J.P.; Mullen, K., Chem. Eur. J., 2000, 6, 4327-4342.
Synthesis – Selective Functionalization
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.
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
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)
Ito, S.; Wehmeier, M.; Brand, J.D.; Kubel, C.; Epsch, R.; Rabe, J.P.; Mullen, K., Chem. Eur. J., 2000, 6, 4327-4342.
LC Phase Characterization – Optical Microscopy
408˚C - Heating 380˚C - Cooling
Textures typical for a columnar liquid crystal phase
Ito, S.; Wehmeier, M.; Brand, J.D.; Kubel, C.; Epsch, R.; Rabe, J.P.; Mullen, K., Chem. Eur. J., 2000, 6, 4327-4342.
LC Phase Characterization – XRD
Br
Br
C10H21
C10H21
C10H21
C10H21
Indicates periodic stacking of aromatic coresHalo associated to liquid-like correlation between aliphatic chains
Ito, S.; Wehmeier, M.; Brand, J.D.; Kubel, C.; Epsch, R.; Rabe, J.P.; Mullen, K., Chem. Eur. J., 2000, 6, 4327-4342.
LC Phase Characterization – STM
Penta-alkyl substituted HBC showed two molecular patternsDimer and rhombic lattice
Ito, S.; Wehmeier, M.; Brand, J.D.; Kubel, C.; Epsch, R.; Rabe, J.P.; Mullen, K., Chem. Eur. J., 2000, 6, 4327-4342.
H
C14H29
C14H29
C14H29
C14H29
C14H29
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
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)
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.
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
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.
Application-Driven Assemblies –Graphitic Nanotubes
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.
Application-Driven Assemblies –Graphitic Nanotubes
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.
Application-Driven Assemblies –Graphitic Nanotubes
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.
Application-Driven Assemblies –Graphitic Nanotubes
Polarized optical microscopy suggests thatnanotube bundles oriented unidirectionallyalong fiber axis
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.
Application-Driven Assemblies –Graphitic Nanotubes
Fibers doped with I2ESR indicates generation of radical species as charge carriersResistivity decreases with temperature
Resistivity betweenfibers
Resistivity alongfiber axis
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.
Application-Driven Assemblies –Graphitic Nanotubes
Con
duct
ivity
x 1
0-8
(S/c
m)
Conductivity alongfiber axis
Conductivity betweenfibers
Conductivities observed parallel and perpendicular to the fiber axis
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.
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.
Application-Driven Assemblies - Photovoltaics
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.
Application-Driven Assemblies - Photovoltaics
Dicarboximide-perylene
HBC-PhC12SEM of ~50/50 mixture HBC-PhC12-Perylene blend spin-coated on Si substrate
AFM of HBC-PhC12 – PeryleneBlend
MacKenzie, J.D.; Friend, R.H.; Moons, E.; Fechtenkotter, A.; Schmidt-Mende, L.; Mullen, K. Science, 2001,293, 1119-1122.
Application-Driven Assemblies - Photovoltaics
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
MacKenzie, J.D.; Friend, R.H.; Moons, E.; Fechtenkotter, A.; Schmidt-Mende, L.; Mullen, K. Science, 2001,293, 1119-1122.
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.