Tuning the redox profiles of polyoxovanadate-alkoxide clusters via heterometal installation: toward designer redox Reagents†
Herein, we describe a rational synthetic approach for tuning the electrochemical profiles of a series of Lindqvist polyoxovanadate-alkoxide clusters through heterometal functionalization. Synthetic procedures for group(IV) functionalization of the mixed-valent POV-alkoxide cluster, [V6O7(OCH3)12], are established, resulting in the heterometallic species, [NBu4][V5O6(OCH3)12MOCH3] (M = Ti, Zr, Hf). We demonstrate that these d0, heterometallic dopants anodically shift the potential of the electrochemical processes associated with the cluster, making the molecule more resistant to oxidation. Conversely, incorporation of electron rich heterometals yields a more readily oxidized molecule, with redox processes shifted cathodically. The predictable tuning and remarkable electrochemical profiles of this family of heterometal-functionalized polyoxometalates highlights their potential use as designer redox agents.