Electronic and geometric structure of cationic and neutral chromium and molybdenum ammonia complexes
Electronic and geometric structure of cationic and neutral chromium and molybdenum ammonia complexes
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DOI：
10.1063/5.0054648
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发表时间：
2021-07-07
影响因子：
4.4
通讯作者：
Miliordos, Evangelos
中科院分区：
文献类型：
--
作者：
Jackson, Benjamin A.;Miliordos, Evangelos
用高水平量子化学方法研究了M（NH_3）（n）和M（NH_3）（n）（+）（M = Cr，Mo，n = 1-6）的几何结构和电子结构.这些配合物具有双壳层电子结构的内金属（3d或4d）轨道和外扩散轨道周围的复杂的周边。电子激发揭示了这两个壳层实际上是相互独立的。钼和铬氨络合物被发现在几何形状上显著不同，前者采用八面体几何形状，而后者是Jahn-Teller畸变八面体结构，其中只有轴向畸变是稳定的。在第二溶剂化壳层中有两个氨分子的六配位配合物和四配位配合物被发现是能量竞争的。电子激发能和计算的红外光谱提供，使两个异构体进行实验区分。这项工作是一个正在进行的努力，研究过渡金属溶剂化电子前体的周期性趋势的一个组成部分。
High level quantum chemical approaches are used to study the geometric and electronic structures of M(NH3)(n) and M(NH3)(n)(+) (M = Cr, Mo for n = 1-6). These complexes possess a dual shell electronic structure of the inner metal (3d or 4d) orbitals and the outer diffuse orbitals surrounding the periphery of the complex. Electronic excitations reveal these two shells to be virtually independent of the other. Molybdenum and chromium ammonia complexes are found to differ significantly in geometry with the former adopting an octahedral geometry and the latter a Jahn-Teller distorted octahedral structure where only the axial distortion is stable. The hexa-coordinated complexes and the tetra-coordinated complexes with two ammonia molecules in the second solvation shell are found to be energetically competitive. Electronic excitation energies and computed IR spectra are provided to allow the two isomers to be experimentally distinguished. This work is a component of an ongoing effort to study the periodic trends of transition metal solvated electron precursors.