Synthesis and structural characterization of Lindqvist type mixed-metal cluster anion [V < inf > 2 < /inf > W < inf > 4 < /inf > O < inf > 19 < /inf > ] < sup > 4- < /sup > in discrete and coordination polymer compounds

Abstract

Two vanadium substituted Lindqvist type tungsten heteropolyanion containing compounds with molecular formulae [HMTAH]2[H2V 2W4O19]·4H2O (1) and [Na 2(H2O)4]n[H2V 2W4O19]n·2nHMTA· 2nH2O (2) have been synthesized, where HMTA is hexamethylenetetramine. Compound 1 is a discrete compound, whereas, compound 2 is a coordination polymer. Compounds 1-2 are characterized by routine elemental analyses, FT-IR spectroscopy, electronic absorption spectral analyses, thermogravimetric studies and single crystal X-ray crystallography. The presence of vanadium in the cluster anion is confirmed by 51V NMR spectroscopy, EDS and ICP analyses. The crystal structures of compounds 1 and 2 are refined in orthorhombic space group Immm and monoclinic space group C2/c respectively. © 2014 Elsevier B.V. All rights reserved.