文献类型：期刊文献

英文题名：Photodegradation of cyanine and merocyanine dyes

作者：Yang, Songjie[1]; Tian, He[1]; Xiao, Heming[2]; Shang, Xinghong[2]; Gong, Xuedong[2]; Yao, Side[3]; Chen, Kongchang[1]

机构：[1]E China Univ Sci & Technol, Inst Fine Chem, Shanghai 200237, Peoples R China;[2]Nanjing Univ Sci & Technol, Dept Chem, Nanjing 210094, Peoples R China;[3]Acad Sinica, Shanghai Inst Nucl Res, Shanghai 201800, Peoples R China

年份：2001

卷号：49

期号：2

起止页码：93

外文期刊名：DYES AND PIGMENTS

收录：;EI(收录号：2001276563434);WOS:【SCI-EXPANDED(收录号:WOS:000168931600003)】；

语种：英文

外文关键词：photodegradation; cyanine dyes; MO calculations; GC/MS

摘要：The photodegradation kinetics for some cyanine and merocyanine dyes was studied by UV-visible spectroscopy and the results show that the fading process follows quasi-first-order or zero-order kinetics in acetonitrile. In other experiments, the principal photodegradation products of the dyes were identified with the aid of GC/MS, and it was found that those cyanine dyes holding a positive charge had higher photostability than the corresponding merocyanines. The relationship between photostability and chemical structure was established using PM3 and AMI MO calculations. Experimental results in this regard suggest that the species associated with the photodegradation of cyanine dyes may be the semioxidized dye free radical cation, Dye(dagger). The transient absorption spectra of Dye(dagger) were determined by nanosecond pump and probe spectroscopy. (C) 2001 Elsevier Science Ltd. All rights reserved.