Emission and transient absorption measurements of substitution effects of C–C triple bonds on relaxation processes of the fluorescent state of naphthalenes
作者:Minoru Yamaji、Hajime Maeda、Keita Minamida、Tomohiro Maeda、Kengo Asai、Gen-Ichi Konishi、Kazuhiko Mizuno
DOI:10.1007/s11164-012-0652-4
日期:2013.1
Photophysical and photochemical properties of naphthalenes substituted with trimethylsilylethynyl, tert-butylethynyl, and trimethylsilylbutadiynyl groups were investigated by measurement of fluorescence yields, lifetimes, and triplet absorption. Introducing trimethylsilylethynyl and tert-butylethynyl groups to the 1-position of the naphthalene skeleton substantially enhanced fluorescence and intersystem crossing (ISC). The rates of fluorescence of 2-substituted naphthalenes were low. The effect of ethynyl groups on the 1-substituted naphthalenes was rationalized in terms of an increase of the transition moment along the short axis of the naphthalene skeleton. Substitution of the trimethylsilylbutadiynyl group at the 1 or 2-position of the naphthalene skeleton caused a considerable decrease in the fluorescence yield (approximately 0.01) and an increase in the ISC yield (0.99).
用三甲基硅基乙炔、叔丁基乙炔和三甲基硅基丁二炔基取代的萘的光物理和光化学性质通过测量荧光产率、寿命和三重态吸收进行研究。在萘骨架的1位引入三甲基硅基乙炔和叔丁基乙炔基团显著增强了荧光和内部转换(ISC)。2位取代的萘的荧光速率较低。乙炔基团对1位取代萘的影响可以通过萘骨架短轴上的跃迁矩增加来解释。在萘骨架的1位或2位替代三甲基硅基丁二炔基团导致荧光产率显著降低(约为0.01),而ISC产率增加(0.99)。