Synthesis and crystal structure of two polyoxometalate complexes NaH3SiW12O40 center dot 17H(2)O and [Mn(H2O)(4)](2)(H2SiW12O40)(2)center dot 13H(2)O

Two polyoxometalate-based complexes, NaH3SiW12O40 center dot 17H(2)O (1) and [Mn(H2O)(4)](2)(H2SiW12O40)(2)center dot 13H(2)O (2), have been hydrothermally synthesized and characterized by IR spectra, thermal analysis, and X-ray single crystal diffraction. The results reveal that the Na(I) in 1 is in a distorted octahedral geometry with two coordinated waters and four O-t from four alpha-[H3SiW12O40](-) anions, while each alpha-[H3SiW12O40](-) is connected with four Na(I) by four Ot. The Na-O and hydrogen bonds connect 1 into a 3-D framework. Complex 2 consists of two alpha-[H2SiW12O40](2-) anions and two [Mn(H2O)(4)](2+) cations, each Mn(II) is coordinated by four waters and two Ot from two alpha-[H2SiW12O40](2-) anions; the clusters are assembled into a 3-D supramolecular network by hydrogen bonds.