Photochemistry of 5-allyloxy-tetrazoles: steady-state and laser flash photolysis study
作者:L. M. T. Frija、I. V. Khmelinskii、C. Serpa、I. D. Reva、R. Fausto、M. L. S. Cristiano
DOI:10.1039/b718104c
日期:——
-N=bridge and the proton shifted to the oxazine ring. Both tautomeric forms are relevant in the photolysis of oxazines in solution. Secondary reactions were observed, leading to the production of phenyl vinyl-hydrazines, enamines, aniline and phenyl-isocyanate. Transient absorption, detected by laser flash photolysis, is attributed to the formation of triplet 1,3-biradicals generated from the excited 5-allyloxy-tetrazoles
通过产物分析和激光闪光光解研究了三个5-烯丙氧基四唑在甲醇,乙腈和环己烷中的光化学。鉴定出的唯一主要光化学过程是分子氮的消除,形成了1,3-恶嗪。通过硅胶柱色谱法以合理的收率分离出这些化合物,并进行了充分表征。DFT(B3LYP)/ 6-31G(d,p)计算表明,这些1,3-恶嗪可采用两种互变异构形式(i)NH基团充当连接恶嗪和苯环的桥,以及(ii)与-N =桥,并且质子移至恶嗪环。两种互变异构形式都与溶液中的恶嗪光解有关。观察到第二反应,导致产生苯基乙烯基肼,烯胺,苯胺和苯基异氰酸酯。通过激光闪光光解检测到的瞬态吸收归因于由激发的5-烯丙氧基四唑产生的三重态1,3-双自由基。通过质子转移将1,3-双自由基转化为1,6-双自由基,在系统间交叉后,该衰变生成产物。溶剂对光产物分布和分解速率的影响可以忽略不计。