A novel copper molybdate inorganic–organic hybrid network synthesized by in-situ generation of pyridine-4-carboxylic ion from 1,3-bis(4-pyridyl) propane precursor

Polyoxometalate-supported transition metal complexes for the oxidative cross-coupling of amines and alcohols

Three new hybrid polyoxometalates (POMs) based on transition metals, namely, copper metal with γ-[Mo8O26]4- polyoxometalates [Cu(DMF)4(Mo8O26)·2C3H8NO]·1.8 DMF (1), cobalt metal with hexamolybdate [Co(DMSO)6][Mo6O19] (2), and nickel metal with hexamolybdate [Ni(DMSO)6][Mo6O19] (3), were developed. These materials were characterised by applying both analytical and spectroscopic techniques (IR, TGA, and CHNO elemental analysis), and structural elucidation was performed using single-crystal X-ray diffraction studies. Among these hybrid POMs, octamolybdate with copper was used for the catalytic production of benzimidazoles. The incorporation of [Cu(DMF)4] between two octamolybdates results in the transformation of POMs into a useful catalyst, which effectively catalyses the oxidative cross-coupling of anilines, benzyl alcohol, and sodium azide to produce benzimidazole. This catalytic reaction occurs in the presence of tert-butyl hydroperoxide (TBHP) at a moderate temperature. Benzimidazole and its derivatives are highly preferred owing to their wide-ranging biological activities and clinical applications. These compounds are exceptionally effective in terms of their selectivity ratio and inhibitory activity. The catalytic reaction presented herein is a one-pot procedure that includes a series of reactions, such as C-H functionalization, condensation, ortho selective amination, and cyclization.

Supramolecular cooperative interaction-induced assembly of phosphotungstate polyanions and sulfur-containing pyridine-based cations

Three crystals were assembled by means of multiple weak intermolecular cooperative supramolecular interactions of hydrogen bonding, S⋯O, C–H⋯π, and polyanion–π.

Polyanionic clusters embedded in lattice-type hydrogen bonding networks involving in situ bond activation and coupling of organic cations

Grid-type hydrogen bonding networks of organic cations are used to capture pseudo-spherical Keggin-type anionic clusters.