Two dumbbell-like polyoxometalates constructed from capped molybdovanadate and transition metal complexes

Self assembly of NaVO3, Na2MoO4 center dot 2H(2)O and NiCl2 center dot 6H(2)O with the assistance of organic liginds under hydrothermal conditions results in two molybdovanadates [Ni(enMe)(2)](4){[Ni(enMe)(2)(H2O)](2)[Ni(enMe)(2)][((VMo8V4)-Mo-V-V-VI O-IV(40))((VO)-O-IV)(2)](2)}center dot 10H(2)O (1) and [Ni(enMe)(2)](5){[Ni(enMe)(2)](2)[((VVMo4Mo4V4)-Mo-VI-V-V O-IV(40))((VO)-O-IV)(4)](2)}center dot 2H(2)O (2), (enMe = 1,2-diaminopropane), which have been characterized by single crystal X-ray diffraction analysis, IR spectroscopy, and elemental analysis. Both of the two compounds exhibit dumbbell-like structures constructed from capped polyoxomolybdovanadates and [Ni(enMe)(2)](2+) complexes. Polyoxoxanion 1 is composed of two bicapped Keggin-type anions [((VMo8V4O40)-Mo-V-O-IV)((VO)-O-IV)(2)](7), one [Ni(enMe)(2)](2+) bridging fragment and two decorated nickel(II) complexes. Polyxoxanion 2 consists of two tetracapped molybdenum-vanadium polyoxoanions [((VMo4Mo4V4)-Mo-V-Mo-VI-V-V O-IV(40))((VO)-O-IV)(4)](7), one [Ni(enMe)(2)](2+) bridging fragment and a nickel(II) decorated fragment. Polyxoxanions 1 and 2 are further linked to form three-dimensional supramolecular networks through extensive hydrogen bonding interactions. In addition, photocatalysis properties of these two compounds have been investigated. Crown Copyright (C) 2010 Published by Elsevier B.V. All rights reserved.