Computational Analysis of Transition Metal-Terminal Boride Complexes

摘要: A computational analysis of model transition-metal terminal boride [MB(PNPR)] complexes is reported. combination density functional theory methods, natural bond orbital analysis, and multiconfiguration self-consistent field calculations were employed to investigate the structure bonding complexes, in particular, extent metal dπ–boron pπ bonding. Comparison metal–boride, −borylene, and–boryl lengths confirms presence metal–boron π bonds, albeit modest shortening (∼3%) suggests that π-bonding very weak borides. Calculated free energies H2 addition yield corresponding boryl indicate metal–boride π-bond strengths are 22 kcal/mol or less as compared 44 for an analogous nitride complex. It concluded that, studied, covering a range different 4d 5d metals, consists reasonably covalent σ but t...