An unexpected semi-hydrogenation of a ligand in the complexation of 2,7-bispyridinyl-1,8-naphthyridine with Ru3(CO)12

Abstract

Thermal reaction of 2,7-bis(2-pyridinyl)-l,8-naphthyridine (bpnp) with Ru₃(CO)₁₂ in the presence of moisture resulted in the formation of a formate-bridged diruthenium complex [(bpnp-H₃)Ru₂(μ-HCOO)(CO)₄] (1), in which the ligand was partially hydrogenated. Complex 1 was fully characterized by spectroscopic analyses and X-ray single crystal determination. Regarding the partially reduced ligand in 1, it occurs through a water–gas shift type reduction. The bridging formate ligand can be substituted by other carboxylate ligands. Physical and chemical properties of the newly prepared complexes were investigated.