Synthesis, crystal structure and catalytic activity in reductive amination of di-chlorido-(η 6 - p -cymene)(2'-di-cyclo-hexyl-phosphanyl-2,6-di-meth-oxy-biphen-yl-κ P )ruthenium(II).

The title compound, [RuCl2 (C10 H14 )(C26 H35 O2 P)] ( I ), crystallizes in the monoclinic space group P 21 / c with two crystallographically independent mol-ecules ( A and B ) in the asymmetric unit. The geometries of both mol-ecules 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 mol-ecules A and B , respectively]. The Ru atoms have classical pseudo-tetra-hedral piano-stool coordination environments. The conformation of each mol-ecule is stabilized by intra-molecular C-H⋯O and C-H⋯Cl hydrogen bonds and C-H⋯π inter-actions. The two mol-ecules are linked by a C-H⋯Cl hydrogen bond. In the crystal, the mol-ecules are further linked by C-H⋯ π inter-actions, forming - A - B - A - B - chains propagating along the a -axis direction. Complex I is an active catalyst for reductive amination reaction. The catalytic activity of this complex can be explained by the lability of the p -cymene ligand, which can be replaced by two-electron ligands such as CO or amine.