Supplementary materials
Theoretical investigations on electronic structures of bipolar host materials
based on carbazole-based triphenylphosphine oxide derivatives for blue
phosphorescence
Huili Sun, Wei Shen, Xiaguang Zhang, Dongmei Zhang, Ming Li*
School of Chemistry and Chemical Engineering, Southwest University, Chongqing
400715, P. R. China
*
E-mail: liming@swn.edu.cn; phone:+86-023-68253023
In order to further understand the effect of different substituents attached to the
triphenylphosphine oxide acceptor backbone chain and the carbazole donor pendant
chains on the electronic properties such as HOMO and LUMO, ET, ∆EST,
reorganization energy (λh and λe), we introduced fluorine (-F) and nitrile (-CN) groups
into four phenyls of backbone chain, i.e., hosts 4−9. The results are shown in Fig.
S1−3 and Table S4−5. The introduction of -CN (or tert-butyl) in triphenyl-phosphine
acceptor (or carbazole donor) moiety also shifts the ET downward for these host
molecules, due to their strong electron-withdrawing inductive effects (or
electron-donating effects) facilitating the delocalization of triplet exciton. The LUMO
levels (EAs) are more vulnerable to CN-substituents than the HOMO levels (IPs). For
example, the LUMO energies of hosts 5 and 7 are significantly stabilized by 1.57 eV
compared with hosts 4 and 6, respectively. Still, CN-series molecules possess far
smaller ΔEST values and lower charge injection barriers than F-series molecules. In
addition, hosts 8 and 9 introduced two kinds of substituents in triphenyl-phosphine
acceptor units can also indeed mediate their performance parameters lying between
those of the corresponding F-substituent molecules (4 and 6) and CN-substituent
molecules (5 and 7). Therefore, this can further confirm the above discussed
conclusions.
Supplementary data
Table S1 The calculated HOMO and LUMO energies of FPCzPO via directly
measuring HOMO/LUMO eigenvalues from the optimized S0 results at the different
levels (in eV)
Table S2 Calculated absorption spectra of FPCzPO by various functionals at the
6-311G(d) basis set (in nm)
Table S3 Calculated transition natures of the S1 states of studied host molecules based
on the S0 geometry by TD-DFT calculations
Table S4 Calculated HOMO and LUMO energies, adiabatic triplet energies ET,
adiabatic ionization potential (IP), electron affinity (EA) and reorganization energies
(λh and λe).for the molecules at the PBE0/6−311G(d) level (in eV)
Table S5 Contour plots of the pairs of “Natural Transition Orbitals” based on
TD-DFT calculation
Table S6 A comparison of the ET and ∆EST between bilateral-substituted and
unilateral-substituted hosts
Table S7 The mainly excited energies and oscillator strength (ƒ) for studied host
molecules calculated by TD-DFT
Fig. S1 Chemical structure of studied compounds 4−9
Fig. S2 Spin density distributions for hosts 4−9
Fig. S3 Contour plots of the HOMO and LUMO levels of hosts 4−9 in the ground
state
Table S1 The calculated HOMO and LUMO energies of FPCzPO via directly
measuring HOMO/LUMO eigenvalues from the optimized S0 results at the different
levels (in eV)
B3LYP/
6-31G(d)
-5.30
-1.36
HOMO
LUMO
B3P86/
6-31G(d)
-5.96
-2.01
PBE0/
6-31G(d)
-5.55
-1.24
PBE0/
6-311G(d)
-5.76
-1.50
Exp.[22,23]
-5.70
-2.30
Table S2 Calculated absorption spectra of FPCzPO by various functionals at the
6-311G(d) basis set (in nm)
λabs
PBE0 B3LYP
336
351
320
335
272
331
B3P86
351
335
331
CAM-B3LYP WB97XD M06
291
286
335
226
273
320
225
224
281
Exp.[22,23]
344
329
297
Table S3 Calculated transition natures of the S1 states of studied host molecules based
on the S0 geometry by TD-DFT calculations
Compounds
FPCzPO
E(S0→S1)
3.69
1
2.76
2
3
4
5
6
7
8
9
3.78
2.91
3.69
2.51
3.79
2.59
2.69
2.97
Transition nature
H-1→LUMO (63%)/H-1→L+1 (31%)
HOMO→LUMO
(69%)/HOMO→L+1
(31%)
H-1→LUMO (65%)/H-1→L+1 (30%)
HOMO→LUMO (82%)
H-1→L+1 (75%)
HOMO→LUMO (96%)
H-1→LUMO (23%)/H-1→L+1 (54%)
HOMO→LUMO (95%)
HOMO→LUMO (96%)
H-1→LUMO (100%)
Table S4 Calculated HOMO and LUMO energies, adiabatic triplet energies ET, adiabatic ionization potential (IP), electron affinity (EA) and
reorganization energies (λh and λe).for the molecules at the PBE0/6-311G(d) level (in eV)
Compounds HOMO LUMO
Eg
ET
4
-5.82
-1.55
4.27 3.10
5
-6.01
-3.12
2.89 2.75
6
-6.02
-1.61
4.41 3.17
7
-6.22
-3.24
2.98 3.02
8
-5.85
-2.85
3.00 2.99
9
-6.12
-2.86
3.26 3.08
a,b
Refer to original values of original values (2.6947 and 2.6946)
IP
6.54
6.71
6.81
6.91
6.63
6.92
EA
-0.96
-2.34
-0.97
-2.61
-2.02
-2.11
λh
0.09
0.11
0.09
0.11
0.10
0.09
λe
0.45
0.32
0.43
0.53
0.41
0.49
E(S0→S1) E(S0→T1)
3.69
3.06
2.51
2.50
3.79
3.09
2.60
2.59
a
2.69
2.69b
2.97
2.96
Table S5 Contour plots of the pairs of “Natural Transition Orbitals” based on TD-DFT calculation
Based on the S0 state
Based on the T1 state
Compounds
a
NTO of hole
NTO of particle
λ
NTO of hole
NTO of particle
∆EST
0.63
0.01
0.70
0.01
0.00
0.01
λa
4
0.97
0.94
5
0.99
0.99
a
6
0.99
0.93
7
0.99
0.98
8
0.99
0.98
9
0.99
0.97
λ represents natural transition orbital eigenvalue
Table S6 A comparison of the ET and ∆EST between bilateral-substituted and
unilateral-substituted hosts
Compounds
FPCzPO
4
1
5
2
6
3
7
ET
3.00
3.10
2.76
2.75
3.16
3.17
3.15
3.02
∆EST
0.64
0.63
0.00
0.01
0.69
0.70
0.00
0.01
Table S7 The mainly excited energies and oscillator strength (ƒ) for studied host
molecules calculated by TD-DFT.
Compounds
FPCzPOM
1
2
3
4
5
6
7
States
S0→S1
S0→S2
S0→S19
S0→S12
S0→S14
S0→S16
S0→S1
S0→S2
S0→S19
S0→S11
S0→S14
S0→S16
S0→S1
S0→S2
S0→S24
S0→S5
S0→S8
S0→S17
S0→S1
S0→S2
S0→S23
S0→S9
S0→S11
S0→S18
λabs
336
320
272
350
332
324
327
314
267
338
325
317
336
332
272
438
426
387
327
325
267
401
384
362
ƒ
0.3138
0.3868
0.1748
0.1543
0.1524
0.3684
0.2441
0.2806
0.1209
0.1668
0.0875
0.2906
0.3771
0.2766
0.1699
0.0142
0.0251
0.0084
0.2843
0.2246
0.1189
0.0147
0.0625
0.0228
8
9
S0→S11
S0→S15
S0→S17
S0→S11
S0→S13
S0→S22
357
335
331
339
328
298
0.3942
0.3392
0.0106
0.1548
0.3065
0.0488
Fig. S1 Chemical structure of studied compounds 4−9
Fig. S2 Spin density distributions for hosts 4−9
Fig. S3 Contour plots of the HOMO and LUMO levels of hosts 4−9 in the ground
state.