Acceptor side-chain effects on the excited state dynamics of two-dimensional-like conjugated copolymers in solution

Huo, Ming-Ming and Hu, Rong and Yan, Wei and Wang, Yi-Tong and Chee, Kuan and Wang, Yong and Zhang, Jian-Ping (2017) Acceptor side-chain effects on the excited state dynamics of two-dimensional-like conjugated copolymers in solution. Molecules, 22 (9). 1398/1-1398/14. ISSN 1420-3049

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Abstract

Excited state dynamics of two-dimensional-like conjugated copolymers PFDCN and PFSDCN based on alternating fluorene and triphenylamine main chains and malononitrile pendant acceptor groups with thiophene as π-bridge, have been investigated by using transient absorption spectroscopy. There is an additional conjugated –C=C– bond in PFDCN, which distinguishes it from PFSDCN. The lowest energy absorption band of each copolymer absorption spectrum is attributed to the π−π* transition with intramolecular charge-transfer, which has a lower fluorescence contribution than those of higher energy absorption bands. The optical excitation of either PFDCN or PFSDCN solution generates polaron pairs that then self-localize and evolve to a bound singlet exciton within a few picoseconds. Due to the additional conjugated –C=C– bond in the acceptor side-chain, PFDCN has a stronger intramolecular charge-transfer characteristic compared with PFSDCN, therefore exhibiting a longer self-localization time (7 ps vs. 3 ps for PFSDCN) and a shorter fluorescence lifetime (1.48 ns vs. 1.60 ns for PFSDCN).

Item Type: Article
Keywords: two-dimensional like conjugated copolymers; acceptor side-chain; transient absorption spectrum; intramolecular charge-transfer characters; excited state dynamics
Schools/Departments: University of Nottingham Ningbo China > Faculty of Science and Engineering > Department of Electrical and Electronic Engineering
Identification Number: 10.3390/molecules22091398
Depositing User: CHEN, Jiaorong
Date Deposited: 07 Feb 2018 08:42
Last Modified: 08 Feb 2018 10:23
URI: http://eprints.nottingham.ac.uk/id/eprint/49572

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