Structural analysis of five-coordinate transition metal boryl complexes with different d-electron configurations.

The site preference of boryl ligands in five-coordinate transition metal boryl complexes has been investigated with the aid of density functional theory calculations. The preferred site for a boryl ligand depends on the electron count of the complex under consideration. Our studies show that the very strong sigma-donating boryl ligands choose to occupy coordination sites such that those orbitals accommodating metal d electrons have minimal metal-boryl sigma-antibonding character.