Two Keggin-type arsenomolybdate organic-inorganic hybrid assemblies decorated by Cu-phen/bpy complexes for photo-/electro-catalytic performance

Abstract

Two Keggin-type arsenomolybdate hybrids modified by Cu-phen/bpy complexes, [Cl{CuII(phen)2}2]2[AsMo12O40]2·H2O (1) and [{CuII(bpy)}{CuII(bpy)2}2 (VIVO)2(AsMoVIMoV7VV4O40)]·H2O (2) (phen ​= ​1,10-phenanthroline, bpy ​= ​2,2′- bipyridyl), were obtained by hydrothermal reaction and structurally characterized via routine techniques. In compound 1, two “butterfly"-shaped {Cu(phen)2} segments share a Cl bridge to form a unique binuclear complex unit {Cl(Cu(phen)2)2}, which further interacts with six {AsMo12O40} clusters via hydrogen bond and other weak interactions yielding a 4,6-connected 3D network. The basic unit of 2 is a hepta-electron reduced tetra-V-substituted Keggin polyoxoanion {AsMoVIMoV7VV4O40}, which is covered by two {VIVO} cap on two trenches of {Mo4O18} group. Two {CuII(bpy)2} segments are connected with the {VIVO} cap of the Keggin skeleton to form a bi-capped and bi-supported structure, which is further connected by {CuII(bpy)} linker leading to a covalent 1-D chains. The 3-D supramolecular network of 2 is formed by abundant hydrogen bonds and π-π interactions. Compounds 1 and 2 show effective photocatalytic performance for degradation of Azon Phloxine dyes under ultraviolet light irradiation and bifunctional electrocatalytic activity for reducing hydrogen peroxide and oxidizing ascorbic acid.