Physicochemical Factors That Influence the Deoxygenation of Oxyanions in Atomically Precise, Oxygen-Deficient Vanadium Oxide Assemblies.

Here, we report our findings related to the structural and electronic considerations that influence the rate of oxygen-atom transfer (OAT) to oxygen-deficient polyoxovanadate alkoxide (POV-alkoxide) clusters ([V6O6(OC2H5)12]n; n = 1-, 0, 1+). A comparison of the reaction times required for the reduction of nitrogen-containing oxyanions (NOx-, x = 2, 3) by the POV-ethoxide cluster in its anionic (1-V6O61-; VIIIVIV5), neutral (4-V6O60; VIIIVIV4VV), or cationic (6-V6O61+; VIIIVIV3VV2) charge state reveals that OAT is significantly influenced by three factors: (1) ion-pairing interactions between the POV-alkoxide and the negatively charged oxyanion; (2) oxidation states of remote vanadyl ions in the Lindqvist assembly; (3) the steric bulk surrounding the coordinatively unsaturated VIII ion. This work provides atomic-level insight related to structure-function relationships that govern the rate of OAT at metal oxide surfaces using polyoxometalate clusters as molecular models.