Hydrothermal Synthesis and Structural Characterization of Two Organic-Inorganic Hybrids Based on Sandwich-type Polyoxometalates

Two novel inorganic-organic hybrid sandwich-type phosphotungstates [H(2)en][Ni(en)(2)](2)[{(alpha-B-PW9O34)(2)Ni-4(H2O)(2)}{Ni(en)(2)(H2O)}(2)] center dot 5H(2)O (1) and [Ni(en)(2)] [Ni(en)(2)(H2O)(2)][{(alpha-B-PW9O34)(2)Ni-4(Hen)(2)}{Ni(en)(2)(H2O)}(2)] center dot 10H(2)O (2) (en = ethylenediamine) have been synthesized by the hydrothermal reactions of trivacant precursors Na-9[alpha-A-PW9O34] center dot 7H(2)O/Na-12[alpha-P2W15O56] center dot 18H(2)O with NiCl2 center dot 6H(2)O in the presence of en and structurally characterized by IR spectra, elemental analyses and thermogravimetric analyses. X-ray crystallographic analyses indicate that 1 is made up of inorganic polyoxoanions [Ni-4(H2O)(2)(alpha-B-PW9O34)(2)](10-) decorated by nickel-organoamine groups, while 2 is constructed from inorganic-organic hybrid polyoxoanions [(alpha-B-W9O34)(2)Ni-4(Hen)(2)](8-) decorated by nickel-organoamine groups.