Authors: Dajiang Huang, Fuming Ying, Sifeng Chen, Chen Zhou, Peifeng Su,* and Wei Wu*

ABSTRACT: A series of theoretical methods, including density functional theory, multiconfiguration molecular orbital theory, and ab initio valence bond theory, are devoted to understanding the metal−ligand bonds in M−BP(BP = biphenyl; M = Sc, Y, or La) complexes. Different from most transition metal−BP complexes, the most stable metal−biphenyl conformers are not half-sandwich but clamshell. Energy decomposition analysis results reveal that the M−BP bonds in the clamshell conformers possess extra-large orbital relaxation. According to the wave function analysis, 2-fold donations and 2-fold back-donations exist in the clamshell M−BP bonds. The back-donations from M to BP are quite strong, while donations from BP to M are quite weak. Our work improves our understanding of the metal−ligand bonds, which can be considered as the “reversed” Dewar−Chatt−Duncanson model.

For more details, please visit https://doi.org/10.1021/acs.inorgchem.2c00144