Twisted intramolecular charge-transfer state of trans-3-(N,N-Dimethylamino)-4'-cyanostilbene: The C-C bond twisting
Journal
JOURNAL OF THE CHINESE CHEMICAL SOCIETY
Date Issued
2023
Author(s)
Hsu, YF
Abstract
Whether a twisted intramolecular charge-transfer (TICT) state is formed is an important issue for understanding the fluorescence properties of a push-pull organic dye. Here we report a position effect of the donor substituent on the TICT state formation of aminostilbenes: namely, trans-3-(N,N-dimethylamino)-4′-cyanostilbene (mDCS) behaves differently from its TICT-free para isomer DCS and forms a TICT state in acetonitrile (MeCN). The TICT state of mDCS also differs from that of many previously reported aminostilbenes by twisting a C−C bond instead of a C−N bond. In addition, among the ring-bridged model compounds mDCS-N, mDCS-C1, and mDCS-C2, we observed an unusual electronic effect of the ring-bridging in mDCS-C2 that mitigates the impact of the TICT state on the fluorescence properties. Both the C−C bond twisting in mDCS and the ring-bridging electronic effect in mDCS-C2 provide new insights into the TICT chemistry of aminostilbenes.
Subjects
photochemistry; physical chemistry; spectroscopy; SUBPICOSECOND TRANSIENT ABSORPTION; TIME-RESOLVED FLUORESCENCE; DUAL EXCITED-STATES; AB-INITIO; 4-DIMETHYLAMINO 4-CYANOSTILBENE; NO EVIDENCE; PHOTOPHYSICS; PHOTOISOMERIZATION; 4-DIMETHYLAMINO-4-CYANOSTILBENE; PHOTOCHEMISTRY
SDGs
Publisher
WILEY-V C H VERLAG GMBH
Type
journal article