Oxygenation of a Ruthenium Complex Bearing a PBP-Pincer Ligand Inducing the Formation of a Boronato Ligand with a Weak Ru–O Bond

A ruthenium hydride complex having a boron-containing PBP pincer ligand was synthesized. Oxygenation of this complex by using NMO formed the corresponding boronate complex with a nearly 90° B–O–Ru angle and a long Ru–O bond. A detailed structural and theoretical study revealed BO double-bond character and a very small contribution of a pπ–dπ interaction between Ru and O.