A stable metal-covalent-supramolecular organic framework hybrid: enrichment of catalysts for visible light-induced hydrogen production

Cubic metal-covalent-supramolecular organic framework (MCSOF-1) hybrid has been created from the reaction of two molecular components and subsequent co-assembly with cucurbit[8]uril (CB[8]) in water. In the presence of CB[8], [Ru(bpy)₃]²⁺ -based acylhydrazine 1·2Cl reacted with aldehyde 2·Cl to quantitatively yield six-armed precursor 3·8Cl through the generation of MCSOF-1. MCSOF-1 combines the structural features of metal-, covalent- and supramolecular organic frameworks. Its periodicity in water and in the solid state was confirmed by synchrotron X-ray scattering and diffraction experiments. MCSOF-1 could enrich discrete anionic polyoxometalates (POMs), maintain periodicity in acidic medium, and remarkably facilitate visible light-induced electron transfer from its [Ru(bpy)₃]²⁺ units to enriched POMs, leading to enhanced catalysis of the POMs for the reduction of proton to H₂ in both aqueous (homogeneous) and organic (heterogeneous) media.