Quantum yield in blue-emitting anthracene derivatives: vibronic coupling density and transition dipole moment density

2014 ◽  
Vol 16 (27) ◽  
pp. 14244-14256 ◽  
Author(s):  
Motoyuki Uejima ◽  
Tohru Sato ◽  
Daisuke Yokoyama ◽  
Kazuyoshi Tanaka ◽  
Jong-Wook Park

Diagonal vibronic couplings in the Franck–Condon S1 state cause torsional distortion, which gives rise to enhancement of fluorescence with a large transition dipole moment.

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Fan-Fang Kong ◽  
Xiao-Jun Tian ◽  
Yang Zhang ◽  
Yun-Jie Yu ◽  
Shi-Hao Jing ◽  
...  

AbstractVibronic coupling is a central issue in molecular spectroscopy. Here we investigate vibronic coupling within a single pentacene molecule in real space by imaging the spatial distribution of single-molecule electroluminescence via highly localized excitation of tunneling electrons in a controlled plasmonic junction. The observed two-spot orientation for certain vibronic-state imaging is found to be evidently different from the purely electronic 0–0 transition, rotated by 90°, which reflects the change in the transition dipole orientation from along the molecular short axis to the long axis. Such a change reveals the occurrence of strong vibronic coupling associated with a large Herzberg–Teller contribution, going beyond the conventional Franck–Condon picture. The emergence of large vibration-induced transition charges oscillating along the long axis is found to originate from the strong dynamic perturbation of the anti-symmetric vibration on those carbon atoms with large transition density populations during electronic transitions.


2004 ◽  
Vol 82 (1) ◽  
pp. 19-26 ◽  
Author(s):  
Xin Zhou ◽  
Ai-Min Ren ◽  
Ji-Kang Feng ◽  
Xiao-Juan Liu

The one-photon absorption (OPA) properties of tetrabenzoporphyrins (TBPs) and phthalocyanines (Pcs) were studied using the semiempirical ZINDO method and time-dependent density functional theory (TDDFT), respectively. The compared results confirmed that the semiempirical ZINDO method was reasonably reliable when calculating the OPA of tetrabenzoporphyrins and phthalocyanines. On the basis of the OPA properties obtained from the ZINDO method, two-photon absorption (TPA) properties of two series of molecules were investigated, using ZINDO and sum-over-states (SOS) methods. The results showed that the TPA cross-sections of all molecules were in the range of 220.6 × 10–50 – 345.9 × 10–50 cm4·s·photon–1, which were in the same order of magnitude as the values reported in the literature. The relatively larger δ(ω) value for Pcs with respect to that for corresponding TBPs originates from larger intramolecular charge transfer, which can be characterized by the difference of dipole moment between S0 and S1 and the transition dipole moment between S1 and S5.Key words: two-photon absorption, ZINDO, sum-over-states, tetrabenzoporphyrin, phthalocyanines.


1998 ◽  
Vol 109 (16) ◽  
pp. 6725-6735 ◽  
Author(s):  
M. Tamanis ◽  
M. Auzinsh ◽  
I. Klincare ◽  
O. Nikolayeva ◽  
R. Ferber ◽  
...  

1974 ◽  
Vol 52 (17) ◽  
pp. 1669-1671 ◽  
Author(s):  
J. Bejar ◽  
H. P. Gush

The fundamental rotation–vibration band of HD has been resolved in the gas at 1 atm pressure. The line width appears to be totally due to the Doppler effect and equals 0.026 cm−1. The transition dipole moment has been calculated from the intensities of lines in the R branch: it is found to vary from 4 × 10−5 D for J = 0 to 7 × 10−5 for J = 4.


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