Sensors and Journalism Seminar, University of British Columbia - Day 1
Seminar at Columbia 09-17-08
Transcript of Seminar at Columbia 09-17-08
Acenes, Fullerenes and Carbon Nanotubes
Glen P. Miller Department of Chemistry and Materials Science Program
University of New Hampshire
Columbia University September 17, 2008
Acenes: Polycyclic aromatic hydrocarbons composed of
linearly annelated benzene rings
(Clar, E. Polycyclic Hydrocarbons; Academic Press Inc: London, 1964; Vol. 1, pp 4-5)
Acene Applications
Acene Degradation:Competing Photo-Oxidation Mechanisms
Substituent Effects on Acene Longevity
Kinetics of Photo-Oxidation
“Substituent Effects in Pentacenes: Gaining Control Over HOMO-LUMO Gaps and Photo-oxidative Resistances,” submitted to JACS
Kinetics of Photo-Oxidation
“Substituent Effects in Pentacenes: Gaining Control Over HOMO-LUMO Gaps and Photo-oxidative Resistances,” submitted to JACS
Evidence for Singlet Oxygen Chemistry
Lessons Learned: Location, Location, Location
Lessons Learned:Steric Resistance is Important
“Substituent Effects in Pentacenes: Gaining Control Over HOMO-LUMO Gaps and Photo-oxidative Resistances,” submitted to JACS
Lessons Learned: ED and EW Groups Offer Unique Electronic Effects
“Substituent Effects in Pentacenes: Gaining Control Over HOMO-LUMO Gaps and Photo-oxidative Resistances,” submitted to JACS
Steric & Electronic Effects Combined
“Substituent Effects in Pentacenes: Gaining Control Over HOMO-LUMO Gaps and Photo-oxidative Resistances,” submitted to JACS
Arylthio and Alkylthio Substituted Pentacenes are the Big Winners
Thin-Film Characteristics
“Substituent Effects in Pentacenes: Gaining Control Over HOMO-LUMO Gaps and Photo-oxidative Resistances,” submitted to JACS
HOMO & LUMO Energies
HOMO & LUMO Energies and Gapspentacenederivative
(t1/2)
E1/2 [O]a
(mV)E1/2
[red]a
(mV)
EHOMO
(eV)ELUMO
(eV)Eg,EChem
(eV)low energymax (nm)
Eg,optical (eV)c
EHOMO,DFT, ELUMO,DFT
(eV)
Eg,DFT (eV)
1 (1140) 849, 1093
-1099 -5.17 -3.36 1.81 624, 575, 534 1.86 -5.20, -3.03 2.17
2 (750) 755, 936
-1229, -1726
-5.07 -3.26 1.81 617, 570, 529 1.88 -5.08, -2.89 2.19
3 (620) 899 -1227 -5.21 -3.24 1.97 605, 559, 520 1.94 --- ---
4 (520) 789 -1054 -5.11 -3.42 1.69 643, 591, 548 1.81 -5.08, -3.07 2.01
5 (220) 713 -1485 -5.03 -2.99 2.04 605, 558, 520 1.95 --- ---
6 (40) 695 -1478 -5.01 -3.00 2.01 604, 557, 518 1.96 -4.93, -2.71 2.22
7 (13) 638, 1372
-1543 -4.95 -2.93 2.02 618, 569, 529 1.90 --- ---
8 (9.0) 627, 1224
-1430 -4.93 -3.07 1.86 600, 554, 515 1.93 --- ---
9 (8.5) 682 -1396 -5.00 -3.08 1.92 604, 558, 519 1.94 -4.86, -2.63 2.23
10 (7.3) 536, 1171
-1521 -4.86 -2.97 1.89 602, 556, 518 1.92 --- ---
11 (6.6) 464, 1081
-1651 -4.78 -2.84 1.94 583, 539, 501 2.01 --- ---
12 (3.7) 635, 1183
-1407 -4.95 -3.07 1.88 621, 573, 532 1.88 -4.80, -2.59 2.21
Pentacene(7.5)f
582, 537, 501 2.08 -2.67, -4.96 2.29
Pent.HOMO (Expt.)
LUMO (Expt.)
Gap (Expt.)
HOMO (DFTtzv)
LUMO (DFTtzv)
Gap (DFTtzv)
HOMO (DFTdzv)
LUMO (DFTdzv)
Gap (DFTdzv)
1 -5.17 -3.36 1.81 -5.20 -3.03 2.17 -4.78 -2.7 2.08
2 -5.07 -3.26 1.81 -5.08 -2.89 2.19 -4.69 -2.59 2.10
3 -5.11 -3.42 1.69 -5.08 -3.07 2.01
4 -5.01 -3.00 2.01 -4.93 -2.71 2.22 -4.54 -2.39 2.15
5 -5.00 -3.08 1.92 -4.86 -2.63 2.23 -4.49 -2.33 2.16
6 -4.95 -3.07 1.88 -4.80 -2.59 2.21 -4.43 -2.27 2.16
MAD=0.07 MAD=0.38 MAD=0.32 MAD=0.45 MAD=0.70 MAD=0.24
Blue Cells = Electrochemically Derived ValuesGreen Cells = Computationally Predicted ValuesYellow Cells = Mean Absolute Deviations (MAD)
All Energies Reported in eV DFTtzv = B3LYP/6-311+G**DFTdzv = B3LYP/6-31G*
Computing HOMO & LUMO Energies
• TZV basis set used with B3LYP gives accurate HOMO energies for variety of substituted pentacenes
• LUMO energy levels are systematically wrong
• HOMO-LUMO Gaps for DZV B3LYP are closer to experiment by “cancellation of errors”
Computing HOMO & LUMO Energies
HOMO-LUMO Energy Gaps for [n]Acenes: (n = 2-9) B3LYP/6-31G*
Ring # [n] HOMO (eV) LUMO (eV) Gap
2 -6.14 -1.41 4.73
3 -5.57 -2.04 3.53
4 -5.20 -2.46 2.74
5 -4.94 -2.76 2.18
6 -4.74 -2.98 1.76
7 -6.72 -5.31 1.41
8 -6.02 -4.62 1.40
9 -6.72 -5.56 1.16
B3LYP/6-311+G**//B3LYP/6-31G*
HOMO LUMO Gap
-6.09 -1.40 4.69
-5.53 -2.02 3.51
-5.16 -2.44 2.72
-4.90 -2.74 2.16
-4.71 -2.96 1.75
-4.70 -2.98 1.72
-4.67 -3.03 1.64
-4.62 -3.08 1.54
B3LYP/6-31G*
Green = Closed-Shell Solutions Blue = Open-Shell Solutions
Comparing Basis-Sets for [n]Acenes: 6-31G* vs. 6-311+G**
n
Ring # [n] HOMO (eV) LUMO (eV) Gap
2 -6.14 -1.41 4.73
3 -5.57 -2.04 3.53
4 -5.20 -2.46 2.74
5 -4.94 -2.76 2.18
6 -4.74 -2.98 1.76
7 -4.74 -3.00 1.74
8 -4.70 -3.05 1.65
9 -4.66 -3.11 1.55
B3LYP/6-31G*
Green = Closed-Shell Solutions Blue = Open-Shell Solutions
n
HOMO LUMO Gap
-6.09 -1.40 4.69
-5.53 -2.02 3.51
-5.16 -2.44 2.72
-4.90 -2.74 2.16
-4.71 -2.96 1.75
-4.70 -2.98 1.72
-4.67 -3.03 1.64
-4.62 -3.08 1.54
B3LYP/6-311+G**//B3LYP/6-31G*
Comparing Basis-Sets for [n]Acenes: 6-31G* vs. 6-311+G**
Approaching “Band-Gap Engineering”: Substituent Effects on Pentacene Derivatives
R
R
R HOMO LUMO GAP-O- 3.72 4.13 0.41
-NH2 -4.10 -2.45 1.65
-OH -4.89 -2.78 2.11
-H -4.96 -2.67 2.29
-SCH3 -5.08 -2.89 2.19
-CN -5.70 -3.76 1.94
-CCH -5.05 -3.12 1.93
-CHO -5.50 -3.66 1.84
-S+(CH3)2 -10.94 -9.20 1.74
6,13-Disubstituted Pentacenes:Geometries, Energies and Surfaces Computed from B3LYP/6-311+G**
Recall:Hexacene Gap = 1.8Heptacene Gap = 1.7
Exploiting Substituent Effects to Prepare Large, Persistent Acenes
C60
C60 – Pentacene Monoadduct
J. Mack and G. P. Miller, Fullerene Science & Technology 1997, 5, 607
Fullerene-Acene Chemistry
G. P. Miller, J. Briggs, J. Mack, P. A. Lord, M. M. Olmstead, A. L. Balch, Organic Letters 2003, 5, 4199
Fullerene-Acene Chemistry
C60
85% Isolated6,13-Diphenylpentacene
Fullerene-Acene Chemistry
G. P. Miller and J. Mack, Organic Letters 2000, 2, 3979
3.2 Å
1.55 Å2.26 Å
123.9o154.5o
G. P. Miller, J. Mack, and J. Briggs, Organic Letters 2000, 2, 3983
Fullerene-Fullerene Stacking
Fullerene-Fullerene Stacking
G. P. Miller, J. Briggs, J. Mack, P. A. Lord, M. M. Olmstead, A. L. Balch, Organic Letters 2003, 5, 4199
-Stacking in Graphite: d = 3.35 Å
Spacial Dependence of [60]Fullerene-[60]Fullerene -Stacking Interactions
O
O
O
O
+
O
O
C60
1
1.1
G. P. Miller and J. Briggs, Tetrahedron Letters 2004, 45, 477
cis,cis-Tris[60]Fullerene Adduct
G. P. Miller and J. Briggs, Organic Letters 2003, 5, 4203
More Fullerene-Acene Chemistry:Kaur, I. and Miller, G. P., New J. Chem. 2008, 32, 459-463.
J. E. Rainbolt, G. P. Miller, J. Org. Chem. 2007, 72, 3020–3030A.J. Athans, J. B. Briggs, W. Jia, G. P. Miller, J. Mat. Chem. 2007, 17, 2636–2641
J. Briggs and G. P. Miller, Comptes Rendus Chimie 2006, 9, 916
O
O
Ph
Ph
Ph
Ph
O
Ph
Ph
O
O
+
Ph
Ph
Ph
Ph
DDQ
C60
HI
AcOH
BrBr
Ph
Ph
Ph
Ph
Ph
Ph
Ph
Ph
Ph
Ph
CH2Br
CH2Br
Nonacene
Cyclodecacene
DDQC60
N2dark
AlCl3 /N2Pd/C
Path Forward: Making Cyclacenes Using Fullerene-Acene Chemistry
Path Forward: Making SWNCs Using Cyclacenes
SWNCs with Uniform, Tunable Properties: Band-Gap Engineering
G. P. Miller, S. Okana, D. Tománek, J. Chem. Phys. 2006, 124, 121102
Other Nanostructured
Carbons
Fullerene Nanotubes
[60]Fullerene Nanotubes
Rauwerdink, K., Liu, J.-F., Kintigh, J. and Miller, G. P., Microscopy Research & Technique, 2007, 70, 513-521
Functionalized Fullerenes & Fullerene Nanotubes for OPVs
Functionalized Fullerenes & Fullerene Nanotubes for OPVs
Acknowledgements