Synthesis, crystal structure and catalytic activity in reductive amination of dichlorido(η⁶-p-cymene)(2′-dicyclohexylphosphanyl-2,6-dimethoxybiphenyl-κP)ruthenium(II)

The title compound, [RuCl₂(C₁₀H₁₄)(C₂₆H₃₅O₂P)] (I), crystallizes in the monoclinic space groupP2₁/cwith two crystallographically independent molecules (AandB) in the asymmetric unit. The geometries of both molecules are very similar and distinguished only by the twist angles of the two benzene rings in the phosphine substituents [89.54 (14) and 78.36 (14)° for moleculesAandB, respectively]. The Ru atoms have classical pseudo-tetrahedral piano-stool coordination environments. The conformation of each molecule is stabilized by intramolecular C—H...O and C—H...Cl hydrogen bonds and C—H...π interactions. The two molecules are linked by a C—H...Cl hydrogen bond. In the crystal, the molecules are further linked by C—H... π interactions, forming –A–B–A–B– chains propagating along thea-axis direction. ComplexIis an active catalyst for reductive amination reaction. The catalytic activity of this complex can be explained by the lability of thep-cymene ligand, which can be replaced by two-electron ligands such as CO or amine.