bridged by the oxamidate anions. For the alpha isomers, the C-C unit of the dianion is nearly perpendicular to the Mo-Mo bonds, and these are essentially perpendicular to each other. For the beta isomers, the corresponding C-C unit and the Mo-Mo bonds are essentially parallel to each other. Each type of isomer is stable in solution. The electronic communication as measured by the DeltaE(1/2) for the oxidation
Mo(2)(O(2)CCH(3))(
DAniF)(3),
DAniF = N,N'-di-p-anisylformamidinate, 与草酰胺二价阴离子 [ArNC(O)C(O)NAr] 的反应(2-), Ar = C(6)H(5) 和对茴香基,给出一对异构化合物,其中 [Mo(2)] 单元由草酰胺阴离子桥接。对于 α 异构体,二价阴离子的 CC 单元几乎垂直于 Mo-Mo 键,并且它们基本上彼此垂直。对于β异构体,相应的CC单元和Mo-Mo键基本上相互平行。每种类型的异构体在溶液中都是稳定的。由 DeltaE(1/2) 测量的每个 Mo(2) 单元氧化的电子通信对于 beta 异构体来说明显更好。在β异构体而不是α异构体氧化时,在近红外区域出现通常称为间隔电荷转移带的现象也支持了这一点。分子力学和 DFT 计算有助于解释 alpha 异构体的相对构象以及 alpha 和 beta 异构体之间的相对能量差异。