Preparation of Cocrystals of 1,4-Diimidazolylbutadiene with a Template Molecule and Dependence of the Cocrystal Photochemical Products on Wavelength
作者:Fanxing Meng、Jing Min、Chunyu Wang、Liyan Wang
DOI:10.1002/ejoc.201600079
日期:2016.4
the other two crystals do not. The DIBD in the cocrystal was irradiated with 313.5 nm light to produce a dimer (a divinylcyclobutane derivative) in high yield through a [2+2] cycloaddition reaction. This dimer then underwent a Cope rearrangement by heating to produce a second dimer, a cyclooctadiene derivative. This second dimer can also be obtained by irradiating the cocrystal with a broadband Hg lamp
(1E,3E)-1,4-二(1H-咪唑-1-基)丁-1,3-二烯(DIBD)与5-甲氧基间苯二酚的共晶、DIBD晶体和DIBD一水合物晶体的制备和表征通过单晶 X 射线分析。共晶满足施密特关于光二聚化的拓扑化学假设,而其他两种晶体不满足。共晶中的 DIBD 用 313.5 nm 光照射,通过 [2+2] 环加成反应以高产率产生二聚体(二乙烯基环丁烷衍生物)。然后该二聚体通过加热进行 Cope 重排以产生第二个二聚体,即环辛二烯衍生物。这种第二个二聚体也可以通过用不带滤光片的宽带汞灯照射共晶来获得。发现 257 nm 光对第二个二聚体的形成至关重要。