Khan Shahriar N, Miliordos Evangelos
Department of Chemistry and Biochemistry, Auburn University, Auburn, Alabama 36849-5312, United States.
J Phys Chem A. 2020 Jun 4;124(22):4400-4412. doi: 10.1021/acs.jpca.0c00693. Epub 2020 May 26.
High-level quantum chemical approaches are performed to study the stability and electronic structure of tri-, di-, monocationic, and neutral scandium ammonia complexes. The calculated binding energies of all Sc(NH) complexes reveal the higher stability of hexa- and octacoordinated systems. The ground states of Sc(NH) and Sc(NH) have a Sc(3d) center, while there are two competitive electronic states for Sc(NH) with a Sc(3d) or a Sc center. The remaining electrons occupy an outer diffuse s-type orbital (1s). The lower lying states involve 3d-3d transitions for Sc(NH) but outer 1s-1p transitions for Sc(NH). The addition of one electron to Sc(NH) reduces the binding energies but shortens the Sc-N bond lengths. The comparison with the vanadium and yttrium ammonia complexes (studied earlier) reveal the unique identity of scandium balancing between a d- and s-block element.
采用高级量子化学方法研究三价、二价、一价阳离子和中性钪氨配合物的稳定性和电子结构。所有Sc(NH)配合物的计算结合能表明六配位和八配位体系具有更高的稳定性。Sc(NH)和Sc(NH)的基态具有Sc(3d)中心，而Sc(NH)存在两个具有Sc(3d)或Sc中心的竞争电子态。其余电子占据一个外层弥散s型轨道(1s)。较低能级的态对于Sc(NH)涉及3d-3d跃迁，但对于Sc(NH)涉及外层1s-1p跃迁。向Sc(NH)添加一个电子会降低结合能，但缩短Sc-N键长。与钒和钇氨配合物（先前已研究）的比较揭示了钪在d族和s族元素之间平衡的独特特性。
