An inert Pt(II)âpyridine bond is considerably labilized upon UV irradiation. On the basis of this phenomenon, kinetically inert Pt(II)-linked coordination rings and cages are formed in high yields from their components by obtaining a kinetically distributed mixture and subsequently equilibrating the mixture into the thermodynamically stable structures upon temporary photolabilization. This method is applicable when the pyridine rings in the ligands are not conjugated with other aromatic rings, in good agreement with DFT calculations that indicate the dependency of the photolability on the Ï-conjugation of the ligand frameworks. Interruption of Ï-conjugation either by introducing an methylene linker or by twisting the aromatic rings are effective to accomplish the photo-induced self-assembly.
惰性
铂(II)-
吡啶键在紫外线照射下会发生明显的唇化。根据这一现象,通过获得一种动力学分布的混合物,然后将混合物平衡为热力学上稳定的结构,就可以从其组分中高产率地形成动力学上惰性的
铂(II)连接配位环和笼。这种方法适用于
配体中
吡啶环未与其他芳香环共轭的情况,这与 DFT 计算结果十分吻合,后者表明光稳定性取决于
配体框架的Ï-共轭情况。通过引入亚甲基连接体或扭转芳香环来中断Ï-共轭,可有效实现光诱导自组装。