A series of new substituted benzo[1,3]oxazines presenting bulky substituents on the chiral oxazine centre were prepared from isopropyl ketones or substituted cyclohexanones. Laser irradiation of these uncoloured compounds in solution promotes the cleavage of the C–O bond and the opening of the [1,3]oxazine ring generating a zwitterionic species, incorporating a 3H-indolium cation and a 4-nitrophenolate
由异丙基酮或取代的
环己酮制备了一系列在手性恶嗪中心上具有较大取代基的新取代苯并[1,3]恶嗪。溶液中这些未着色化合物的激光辐照促进了C–O键的裂解和[1,3]恶嗪环的打开,从而生成两性离子物质,并结合了3 H-
吲哚鎓阳离子和
4-硝基酚酸酯阴离子,从而吸收在440 nm处强。光生有色开放异构体是热不稳定的,并以13到68 ns的一级动力学和寿命恢复为初始封闭形式。这些光致变色开关非常稳定,在重复各种辐照/黑暗周期后不会显示出明显的退化。