Poly[[2-(3-pyridinio)-1H,3H+-benzimidazolium] [μ4-oxido-di-μ3-oxido-tetra-μ2-oxido-hexaoxidotetramolybdenum(VI)]]

Abstract

The reaction of MoO3 with 2-(3-pyridyl)benzoimidazole and water in the presence of MnSO4·5H2O at 453 K under hydrothermal conditions afforded the title compound, {(C12H11N2)[Mo4O13]}n, in which infinite molybdenum oxide anionic chains are charge-balanced by diprotonated 2-(3-pyridyl)benzoimidazole (H23-PBIM2+) cations. Eight [MoO6] octahedra are edge-shared, forming compact octamolybdate subunits which are connected through pairs of Mo—O—Mo bridges into extended one-dimensional arrays propagating along the a-axis direction. The asymmetric unit of the metal oxide chain contains one half of the octamolybdate unit, denoted [Mo4O13], the other half being generated by an inversion center. These molybdenum oxide chains are further connected through the 2-(3-pyridinio)benzoimidazolium cations into a three-dimensional network via N—H...O hydrogen bonds. In addition, neighbouring diprotonated cations are arranged in a head-to-tail fashion with a plane-to-plane separation of 3.63 (10) Å, indicating the existence of weak aromatic π–π stacking interactions.