Synthesis and photochemical properties of stilbenophanes tethered by silyl chains.: Control of (2π+2π) photocycloaddition, cis-trans photoisomerization, and photocyclization
Synthesis and photochemical properties of stilbenophanes tethered by silyl chains.: Control of (2π+2π) photocycloaddition, cis-trans photoisomerization, and photocyclization
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DOI：
10.1021/jo050914
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发表时间：
2005-11-25
影响因子：
3.6
通讯作者：
Tobita, S
中科院分区：
文献类型：
--
作者：
Maeda, H;Nishimura, K;Tobita, S
合成了新型硅链连接的大环和中等尺寸的二苯乙烯类化合物，并对其光化学和光物理性质进行了研究。大环二苯乙烯类化合物直接光照射可得到立体选择性的分子内光环加合物，其效率随二苯乙烯单元间距离的减小而增大。二苯乙烯类化合物的三重态敏化光反应导致顺反光异构化。顺式固定二苯乙烯在氧气气氛下的光反应选择性地生成菲。荧光量子产率随着硅基取代基的引入而增加，因此硅基连接的二苯乙烯类化合物的荧光量子产率比未取代的反式二苯乙烯大。当二苯乙烯中的两个二苯乙烯单元之间的距离足够小时，观察到分子内的准分子发射。
Novel macrocyclic and medium-size stilbenophanes tethered by silyl chains were synthesized, and their photochemical and photophysical properties were examined. Direct photoirradiation of macrocyclic stilbenophanes gave intramolecular photocycloadducts stereoselectively, and the efficiency increased with decreasing distance between the two stilbene units. The triplet-sensitized photoreaction of stilbenophanes caused cis-trans photoisomerization. Photoreactions of cis-fixed stilbenophanes under an oxygen atmosphere selectively gave phenanthrenophanes. Fluorescence quantum yields increased with the introduction of silyl substituents, and hence those of silyl-tethered stilbenophanes were larger than that of unsubstituted trans-stilbene. Intramolecular excimer emission was observed when the distances between two stilbene units in the stilbenophanes were sufficiently small.