title: Vibrationally resolved ¹Lb (¹A')↔S0 (¹A') electronic spectra of benzimidazole and indene: Influence of Duschinsky and Herzberg-Teller effects on weak dipole-allowed transitions.
abstract: Geometrical optimizations of the ground and first excited states of benzimidazole and indene were performed using the density functional theory (DFT) and its time-dependent extension methods (TD-DFT), respectively. Their vibrationally resolved (1)Lb ((1)A')↔S0 ((1)A') absorption and fluorescence spectra were simulated within the Franck-Condon approximation including the Herzberg-Teller (HT) and Duschinsky effects. Calculated results revealed that, with the HT and Duschinsky effects getting involved, the simulated weak (1)Lb ((1)A')↔S0 ((1)A') electronic spectra of the two molecules excellently reproduce the experimental findings. Based on the experimental data and other theoretical results, we tentatively assigned most of the vibrational normal modes which emerged in the experimental spectra of the two molecules. The present theoretical insights are expected to help us understand the nature of electronic transitions in the vibrationally resolved absorption and fluorescence spectra of benzimidazole and its analogues.
authors.affiliation: Key Laboratory of Luminescence and Real-Time Analytical Chemistry (Southwest University), Ministry of Education, College of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715, China.
authors.forename: Pan
authors.initials: P
authors.lastname: Yang
authors.affiliation: Key Laboratory of Luminescence and Real-Time Analytical Chemistry (Southwest University), Ministry of Education, College of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715, China.
authors.forename: Min
authors.initials: M
authors.lastname: Pang
authors.affiliation: Key Laboratory of Luminescence and Real-Time Analytical Chemistry (Southwest University), Ministry of Education, College of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715, China.
authors.forename: Ming
authors.initials: M
authors.lastname: Li
authors.affiliation: Key Laboratory of Luminescence and Real-Time Analytical Chemistry (Southwest University), Ministry of Education, College of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Shen
authors.affiliation: Key Laboratory of Luminescence and Real-Time Analytical Chemistry (Southwest University), Ministry of Education, College of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715, China. Electronic address: herx@swu.edu.cn.
authors.forename: Rongxing
authors.initials: R
authors.lastname: He
keywords: Absorption and fluorescence; Benzimidazole and indene; Duschinsky; Herzberg–Teller