Complexes of non-lacunary Keggin- and Dawson-type polyoxometalates with Pb(ii): formation of 1D coordination polymers with different bonding modes

Abstract

A new coordination polymer based on Keggin-type [SiW12O40]4− and Pb2+ ions, {Pb2(μ2-DMF)2(DMF)8(SiW12O40)} (1a), was prepared by a reaction between H4[SiW12O40] and Pb(NO3)2 in N,N-dimethylformamide (DMF). Varying the crystallization conditions, a complex with a slightly different coordination mode of the {Pb2} unit and solvate composition, {Pb2(μ2-DMF)2(DMF)8(SiW12O40)}·DMF (1b), can be obtained. The complex containing Well–Dawson polyoxoanions, {(Pb(μ2-DMF)3(DMF)6)(Pb(DMF)5)(P2W18O62)}·0.5DMF·1.3H2O (2), was prepared by a similar strategy.