Light‐, Middle‐ and Heavy‐Lanthanide Ate‐Complexes Bearing Ln(III)–Si bonds: Structural, Spectroscopic, and Bonding Analysis

Abstract

Comprehensive SummaryRecent decades have witnessed a rapid development of the lanthanide silicon chemistry. In this research, by reacting [(THF)3LiSiPh3] with Cp3Ln(III)(THF) (Ln(III) = Sm(III), Tb(III), Dy(III), Yb(III)) or Cp2Lu(III)Cl(THF), a series of middle‐ and heavy‐lanthanocene monosilyl/disilyl ate‐complexes ([(DME)3Li][Cp3Ln(III)SiPh3] and [(DME)3Li][Cp2Lu(III)(SiPh3)2]) were synthesized. The structures of the obtained lanthanocene monosilyl/disilyl ate‐complexes were determined by single crystal X‐ray diffraction. Together with the previously reported [(DME)3Li][Cp3La(III)SiPh3] and [(DME)3Li][Cp3Ce(III)SiPh3], a complex group comprising silyl light‐, middle‐ and heavy‐lanthanocene with identical core coordination pattern are presented. The structure analysis of this group of complexes showed that their key geometric parameters, including the Ln(III)–Si bond lengths and Ln(III)–Si–Cph/Cph–Si–Cph angles, were linearly correlated with the ionic radii of Ln(III) centers. Computational studies based on density functional theory calculations suggested the strongly polarized nature of the Ln(III)–Si bonds in these ate‐complexes. The UV‐Vis spectroscopy measurements of this group of ate‐complexes showed that the characteristic absorptions were hypsochromically shifted for complexes with heavier Ln(III) centers. In addition, as revealed by the time‐dependent density functional theory analysis, the HOMOs, in which the Ln(III)–Si σ‐bonding orbitals were the dominant components, of these complexes acted as main donor orbitals in the major electron transitions.