The mechanisms of Large Stokes Shift and Fluorescence Quantum Yields in anilino substituted Rhodamine analogue: TICT and PICT

Authors

Zhiyong Zhang, China University of PetroleumFollow
Guangqing Zhang, University of WollongongFollow
Jingxiu Wang, University of WollongongFollow
Shan Shan Sun, China University of Petroleum
Zhongzhi Zhang, China University of PetroleumFollow

RIS ID

109807

Publication Details

Zhang, Z., Zhang, G., Wang, J., Sun, S. & Zhang, Z. (2016). The mechanisms of Large Stokes Shift and Fluorescence Quantum Yields in anilino substituted Rhodamine analogue: TICT and PICT. Computational and Theoretical Chemistry, 1095 44-53.

Abstract

An anilino substituted rhodamine analogue named 9-(2′-carboxyphenyl)-6-(N,N-diethylamino)-4-(n-phenyl-methanamine)-1,2,3-trihydroxanthylium (1) is investigated by DFT/TDDFT approaches to map its Large Stokes Shift (LSS) and Fluorescence Quantum Yields (FQY) mechanisms. According to PES analysis, both PICT and TICT occur in photoexcitation of 1. The calculated UV-Vis and fluorescence spectra reveal that both PICT and TICT cause LSS. The calculated dual fluorescence indicates 1 can be adequately described by the two state (LE + ICT) mechanism. The calculated Transient Absorption Spectra (TAS) demonstrate that triplet state of 1 may decay from either PICT or TICT through Intersystem Crossing (ISC). With analysis of spontaneous emission, TICT has low FQY, while PICT has high FQY. The research indicates that both PICT and TICT are mechanisms for LSS in 1 and occurrence of PICT is important for increasing FQY for 1.