Surface functionalization of polyoxovanadium clusters: generation of highly soluble charge carriers for nonaqueous energy storage.

Here, we demonstrate the effects of surface functionalization on a tunable series of nano-sized electron shuttles, toward improving their function in nonaqueous energy storage. The synthesis of a series of polyoxovanadium clusters featuring bridging ether functional groups is reported, revealing the influence of bridging "R" group identity on electrochemical stability in solution. Furthermore, the presence of bridging ether moeities yields enhanced solubility in acetonitrile (up to 1.

Investigation of Cubic Fe M Frameworks for Application in Nonaqueous Energy Storage.

Multimetallic complexes have recently seen increased attention as next-generation charge carriers for nonaqueous redox flow batteries. Herein, we report the electrochemical performance of a molecular iron-molybdenum oxido complex, {[(Me TACN)Fe][μ-(MoO κ O,O',O")]} (Fe Mo O ). In symmetric battery charging schematics, Fe Mo O facilitates reversible two-electron storage with coulombic efficiencies >99 % over 100 cycles (5 days) with no molecular decomposition and minimal capacity fade.

Organic Functionalization of Polyoxovanadate-Alkoxide Clusters: Improving the Solubility of Multimetallic Charge Carriers for Nonaqueous Redox Flow Batteries.

The success of nonaqueous redox flow battery technology requires synthetic advances in charge carrier design to increase compatibility with organic solvents. Herein, previous discoveries related to the development of multimetallic charge carriers are built upon with the high-yielding syntheses of ether- functionalized polyoxovanadate-alkoxide clusters, [V O (OR) (OCH ) CR'] (R=CH , C H ; R'=CH , CH OCH , CH OC H OCH ). Like their homoleptic congeners [V O (OR) ] (R=CH , C H ), these clusters exhibit four redox events, spanning nearly a two-volt window, and demonstrate rapid electron-transfer kinetics.

Self-Assembled, Iron-Functionalized Polyoxovanadate Alkoxide Clusters.

Herein we report the synthesis of a series of iron-functionalized, mixed-valent, polyoxovanadate alkoxide clusters, [V5O6(OCH3)12Fe]X (X = Cl, Br, SO3CF3) comprised of a hexanuclear Lindqvist (M6O19(n-)) core. By substituting a V═O moiety from the well-defined hexavanadate clusters [V(IV)nV(V)6-nO7(OR)12](4-n) (R = Me, Et) with a metal cation, we have developed a novel template for investigation of the organometallic properties of these systems. Characterization of the clusters was performed by (1)H NMR, Fourier transform infrared, and electron absorption spectroscopies and electrospray ionization mass spectrometry.