Synthesis and Spectroscopic Characterization of Two New Dawson Sandwich Complexes: Na18[(NaOH)2(VO)2(P2W15O56)2].40H2O and Na18[(NaOH)2(VO)2(As2W15O56)2].27H2O
Reaction of the three vacant complex of a-[P2W15O56]12- and a-[As2W15O56]12- with divalent cation of VO2+ in 1:1 mole ratio yields a previously unknown sandwich-type Wells-Dawson complex; Na18[(NaOH)2(VO)2(P2W15O56)2].40H2O (represented as Na2(VO)2P4W30) and Na18[(NaOH)2(VO)2(As2W15O56)2].27H2O (represented as Na2(VO)2As4W30). These complexes contain anions in which two divalent VO2+ cations with two Na+ ions are symmetrically sandwiched between two α-[P2W15O56]12- or α-[As2W15O56]12- groups leading to a “lacunary” sandwich complex. The anion complexes are isolated as sodium salts and characterized by elemental analysis, TGA, IR, 31P NMR and UV-Vis spectroscopy.
Copyright © 2012 Hindawi Publishing Corporation. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.