Fac-Re(CO)3 core-based complex featuring benzimidazole as pendant motif from hydroxyquinoline and pyridylbenzimidazole

Abstract

Neutral heteroleptic acyclic complex, fac−[Re(CO)3(OQN)(pybimz)] (1), possessing free benzimidazole motif remotely is reported. The complex was obtained from 8-hydroxyquinoline (HOQN), 2-(4′-pyridyl)benzimidazole (pybimz), and Re2(CO)10. The structure of 1 was confirmed using single crystal X-ray diffraction (SCXRD) analysis. The crystal structure of 1 is stabilized by various types of intermolecular non-covalent interactions (π(OQN) ⋅⋅⋅π(OQN), NH^CH(pybimz)⋅⋅⋅O(OQN)−Re, and C−H(pybimz)⋅⋅⋅O≡C−Re). The extended H-bonding contacts between the molecules (C−H(pybimz)⋅⋅⋅O≡C−Re) in the crystal structure result in the cavity containing polymeric network structure in which toluene molecules reside. The solvent toluene molecules occupy ∼35% of the unit cell volume of the crystal. The absorption properties of the complex was studied both experimentally and theoretically.