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Modulation of electronic structures of thienylene vinylene oligomers by substituents and solvents: ground and excited states
Author(s) -
Meng Suci,
Jiang Jie,
Wang Yujuan,
Ma Jing
Publication year - 2009
Publication title -
journal of physical organic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.325
H-Index - 66
eISSN - 1099-1395
pISSN - 0894-3230
DOI - 10.1002/poc.1498
Subject(s) - chemistry , excited state , polarizable continuum model , delocalized electron , density functional theory , photochemistry , solvent effects , singlet state , absorption spectroscopy , polar effect , electronic structure , time dependent density functional theory , basis set , computational chemistry , solvent , atomic physics , organic chemistry , physics , quantum mechanics
The effects of substituents on the electronic structures of di(thienylene vinylene) (2TV) in ground and excited states are studied using density functional theory (DFT) and time‐dependent DFT (TD‐DFT), respectively. A representative set of electron donating groups (amino, methoxy and methyl) and withdrawing groups (acetylene, cyano and nitro) are introduced on the vinylene and thienyl moieties to investigate the influence of substituents. Bulk solvent effects are also taken into account by means of the polarizable continuum model (PCM). In contrast to the aromatic structures of 2TV and its derivatives in their ground (S 0 ) states, the electronic structures of first singlet excited (S 1 ) states are rather delocalized. The electron‐donating/withdrawing capability, position and number of substituents are important factors in tuning the vertical S 0 → S 1 absorption energies and S 1 → S 0 emission energies of 2TV derivatives. The NO 2 ‐ and NH 2 ‐substituents exert significant effects on the geometries of both ground and excited states and hence the absorption and photoluminescence (PL) emission spectra. The solvent polarity introduces modest influence on the excitation energies for most of the 2TV derivatives. But the absorption and PL emission spectra of nitro‐substituted 2TV exhibit noticeable red shifts as the medium polarity increases. Copyright © 2008 John Wiley & Sons, Ltd.