A luminescent bis(pyridyl)-substituted benzimidazole platinum(II) complex exhibiting an intermolecular anagostic interaction.

The photophysical properties of transition metal complexes of the 5,6-dimethyl-2-(pyridin-2-yl)-1-(pyridin-2-ylmethyl)-1H-benzimidazole ligand are of interest. Dichlorido[5,6-dimethyl-2-(pyridin-2-yl)-1-(pyridin-2-ylmethyl)-1H-benzimidazole-κ2N2,N3]platinum(II), [PtCl2(C20H18N4)], is luminescent in the solid state at room temperature. The compound displays a distorted square-planar coordination geometry. The Pt-N(imidazole) bond length is shorter than the Pt-N(pyridine) bond length. The extended structure reveals that symmetry-related molecules display weak C-H...N, C-H...Cl, and C-H...Pt hydrogen-bonding interactions that are clearly discernable in the Hirshfeld surface and fingerprint plots. The intermolecular C-H...Pt and C-H...N interactions have been explored using density functional theory. The result of an analysis of the distance dependence of C-H...Pt yields a value consistent with that observed in the solid-state structure. The energy of interaction for the C-H...Pt interaction is found to be about -11 kJ mol-1.