Latent photochromism (pseudothermochromism) and photofatigue of crystalline 2-(2′,4′-dinitrobenzyl)pyridine
作者:Panče Naumov、Yuji Ohashi
DOI:10.1002/poc.738
日期:2004.10
metastable 2-(2′,4′-dinitrophenylmethylidene)-1,2-dihydropyridine (NH) and the unstable 6-aci-nitro-2-nitro-5-(2′-pyridylmethylene)-1,3-cyclohexadiene (OH), the stable form of 2-(2′,4′-dinitrobenzyl)pyridine (DNBP), CH, is photochemically converted into small amounts of 1,2-bis(2′,4′-dinitrophenyl)-1,2-bis(2′-pyridyl)ethane, trans-bis[5-nitro-2-(pyridine-2-carbonyl)phenyl]diazene N-oxide, 6-nitro-3-(2′-pyridyl)-2
与亚稳态的2-(2',4'-二硝基苯基亚甲基)-1,2-二氢吡啶(NH)和不稳定的6-aci-硝基-2-硝基-5-(2'-吡啶基亚甲基)-1,3- 2-(2',4'-二硝基苄基)吡啶(DNBP)CH的稳定形式环己二烯(OH)被光化学转化为少量的1,2-双(2',4'-二硝基苯基)-1 ,2-双(2'-吡啶基)乙烷,反式-双[5-硝基-2-(吡啶-2-羰基)苯基]二氮杂N-氧化物,6-硝基-3-(2'-吡啶基)-2 ,1-苯并恶唑和3-硝基吡啶[1,2- b] quinolin-6-ium-11-olate。副产物结构的X射线分析和ESR / IR测量结果表明,DNBP的潜在光致变色归因于开壳反应,该反应是由氢光吸收和随后生成两个自由基基团NH引发的。和OH 。。基团的大量(约50%的NH 。和70%OH 。)在晶体内部密闭在环境条件下持续。通过准周期反应,剩余的自由基部分恢复了基态异构体C