Boggiano Andrew C, Studvick Chad M, Steiner Alexander, Bacsa John, Popov Ivan A, La Pierre Henry S
School of Chemistry and Biochemistry, Georgia Institute of Technology Atlanta Georgia 30332-0400 USA
Department of Chemistry, The University of Akron Akron Ohio 44325-3601 USA.
Chem Sci. 2023 Sep 25;14(42):11708-11717. doi: 10.1039/d3sc04262f. eCollection 2023 Nov 1.
A series of Ce complexes with counter cations ranging from Li to Cs are presented. Cyclic voltammetry data indicate a significant dependence of the oxidation potential on the alkali metal identity. Analysis of the single-crystal X-ray diffraction data indicates that the degree of structural distortion of the secondary coordination sphere is linearly correlated with the measured oxidation potential. Solution electronic absorption spectroscopy confirms that the structural distortion is reflected in the solution structure. Computational studies further validate this analysis, deciphering the impact of alkali metal cations on the Ce atomic orbital contributions, differences in energies of Ce-dominant molecular orbitals, energy shift of the 4f-5d electronic transitions, and degree of structural distortions. In sum, the structural impact of the alkali metal cation is demonstrated to modulate the redox and electronic properties of the Ce complexes, and provides insight into the rational tuning of the Ce imidophosphorane complex oxidation potential through alkali metal identity.
本文展示了一系列具有从锂到铯等抗衡阳离子的铈配合物。循环伏安法数据表明氧化电位对碱金属种类有显著依赖性。单晶X射线衍射数据分析表明，第二配位层的结构畸变程度与测得的氧化电位呈线性相关。溶液电子吸收光谱证实结构畸变反映在溶液结构中。计算研究进一步验证了这一分析，揭示了碱金属阳离子对铈原子轨道贡献、铈主导分子轨道能量差异、4f - 5d电子跃迁的能量位移以及结构畸变程度的影响。总之，碱金属阳离子的结构影响被证明可调节铈配合物的氧化还原和电子性质，并为通过碱金属种类合理调节铈亚磷酰亚胺配合物的氧化电位提供了见解。
