Three Polyoxovanadates-Based Organic–Inorganic Hybrids: Structural Variation, Bifunctional Electrocatalytic Activities, and Computational Studies

Three bimetallic organic–inorganic hybrids based on the [V2O6]2– building unit, [Cu(pty)(V2O6)]·H2O (1), [Cu(pty)(V2O6)] (2), [Cu(tpy)(V2O6)] (3), (pty = 4′-(4″-pyridyl)-2,2′:6′,2″-terpyridine, tpy = 2,2′:6′,2″-terpyridine), were synthesized via a one-pot method. Hybrid 1 has a 1D straight chain architecture with [V2O6]2– clusters and Cu-pty complexes; hybrids 2 and 3 possess a 2D sheet structure including 10-membered rings assembled from four [Cu(pty)]2+ motifs and six [V2O6]2– clusters in 2, and two [Cu(tpy)]2+ units and eight [V2O6]2– clusters in 3. Noteworthy, hybrids 1–3 can be employed as bifunctional electrocatalysts for electroreduction of nitrite and electrooxidation of ascorbic acid. Additionally, theoretical calculations including the molecular electrostatic potential and the frontier molecular orbital were performed to estimate the electronic structure of hybrids 1–3. The natural bond orbital analysis was also calculated to interpret the electron charge distribution.