Conformational analysis and synthetic approaches to polydentate perhydro-diazepine ligands for the complexation of gallium(iii)
作者:David Parker、Bradley P. Waldron
DOI:10.1039/c3ob40287h
日期:——
twist-chair conformer in the solid state. Solution state NMR experiments highlight a conformational preference for the bulky aryl groups to adopt an equatorial site, pre-disposing the ligand to metal binding, by adoption of a conformation that creates a facial array of the ligand nitrogen atoms. This ligand conformation averts the formation of less stable metal complexes with differing ligation modes
据报道,合成方法可根据以下方法对多齿配体进行分析: 6-苯基-6-氨基-过氢-1,4-二氮杂。设计的合成路线避免了开环反应,允许在化学选择性的RANEY®镍还原反应之前,单独引入环外N-取代基并涉及硝基-曼尼希缩合反应。四种合成中间体的固态结构比较表明,该七元环在固态下采用了优选的扭转椅构象异构体。溶液状态NMR实验表明,构象偏爱大体积的芳基采用赤道位点,并通过采用可形成配体氮原子表面阵列的构象使配体与金属结合。这种配体构象可避免形成具有不同连接模式的不稳定金属配合物,特别是在Ga 3+与相关配体的结合方面,其中C-甲基取代基取代季中心的苯基。