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论文类型：期刊论文

发表时间：2010-12-01

发表刊物：CHINESE JOURNAL OF CHEMICAL PHYSICS

收录刊物：SCIE、CSCD、Scopus

卷号：23

期号：6

页面范围：637-642

ISSN号：1674-0068

关键字：Volume-conserved twisted state; Time-resolved photon emission; Photoisomerization

摘要：The excited state characters of HY103 have been studied by means of time-resolved photon emission (time-correlated single photon counting) and time dependent density functional theory calculations. The experimental and theoretical results demonstrate that HY103 dyes undergo an efficient one-bond-flip motion after photoexicitation at room temperature, which leads to a very short lifetime of the normal fluorescence state, and a weak fluorescence emission around 670 rim. However, when HY103 are excited in amorphous glasses at 77 K, the normal fluorescence emission is prolonged to nanoseconds time scale about 2 us, and the fluorescence emission is enhanced. Furthermore, a new emission state is produced, which is characterized as a volume-conserved twisted (VCT) state. This is the first observation of a VCT state. The experiment indicates that the VCT motion of excited state of pi-conjugated molecules in restricted environment can form a stable emission state, and the excited state character of pi-conjugated molecules in restricted environment is complex.