苯乙烯基氮氧杂芳烃间的交叉光二聚反应(英文)  

Cross-photodimerization of 4-(2-phenylethenyl )pyridine,2-(2-phenylethenyl )benzoxazole and 5-phenyl-2-(2-phenyl-ethenyl )oxazole

作　　者：庄俊鹏[1] 张文勤[1] 

机构地区：[1]天津大学化学系,天津300072

出　　处：《物理化学学报》2004年第2期173-177,共5页Acta Physico-Chimica Sinica

基　　金：国家自然科学基金(29602006)资助项目~~

摘　　要：用中压汞灯(λ>300nm)照射4-苯乙烯基吡啶、2-苯乙烯基苯并口恶唑和5-苯基-2-苯乙烯基口恶唑三种杂芳基乙烯单体中任意两种的硫酸水溶液,得到三种交叉二聚体.用高效液相色谱跟踪研究了交叉光二聚反应,发现每组反应生成三种光二聚体,其中二种为单体自身的光二聚体,而另外一种是两种不同单体的交叉光二聚体.交叉二聚体通过柱色谱分离得到,其顺式头对尾结构经紫外、红外、氢谱、碳谱和元素分析确定.用紫外光谱和高效液相色谱跟踪研究了交叉光二聚体的稀溶液在低压汞灯(λmax=254nm)照射下的光解反应.研究发现交叉二聚体能够彻底发生光解,首先生成原来的反式单体,所生成的反式单体容易发生异构化而生成顺式单体,最终建立起反顺异构化平衡.Three cross-photodimers were synth esized by irradiation of each two mon omers of 4-(2-phenylethenyl )pyridine,2-(2-phenylethenyl )benzoxazole and 5-phenyl-2-(2-phenylethenyl )oxazole in H 2 SO 4 solution using medi-um-pressure Mercury lamp (λ>300nm)as light source.The cross-photodim erization was monitored by HPLC titr a-tion.The results showed that three p hotodimers were produced in each rea ction,two of them were the self-phot odimers and the other one was the cross-photo dimer.The cross-photodimers were i solated by column chromatography an d their structures with syn-head-to-tail c onfigurations were determined by UV,IR,1 H NMR,13 C NMR and MS.The photolysis of the cross-photodimer was perform ed in dilute methanol solution upon t he irradiation of low-pressure Merc ury lamp (λ=254nm)and monitored by HPLC and UV titratio n.It was found that the cross-photodimer was photolyzed into trans-monomers at first,and then th e new formed trans-monomers were converted into cis-ones by the trans-cis isomer-ization.

关 键 词：苯乙烯基氮氧杂芳烃 交叉光二聚反应 光解反应 反式单体 顺式单体 异构化 杂芳基乙烯 交叉光二聚体 

分 类 号：O631.5[理学—高分子化学]