文摘
Two new supramolecular polyoxometalate compounds [Ag2(mbpy)3][Ag(mbpy)2][PW12O40] (rong class="boldFont">1rong>) and [Ag2(mbpy)3]2[SiW12O40] (rong class="boldFont">2rong>) (mbpy=4,4'-dimethyl-2,2'-dipyridyl), have been hydrothermally synthesized and characterized by IR, TG, and single-crystal X-ray diffraction techniques. The structural feature of rong class="boldFont">1-2rong> is in the cationic moiety of a tetra-core {Ag4} cluster through weak Ag鈥g interactions. The silver(I) centers show three-, four- and five-coordinated geometries. In rong class="boldFont">1rong> the tetrameric silver atoms in {[Ag2(mbpy)3]2}4+ covalently bind to [PW12O40]3鈭?/sup> anion via Ag3O bonds, while there is only intermolecular hydrogen bonding between {[Ag2(mbpy)3]2}4+ and [SiW12O40]4鈭?/sup> in rong class="boldFont">2rong>. The coordination environments of the tetrameric silver cations have a great influence on the structure richness of the Keggin-based hybrids. The fluorescence properties of compounds rong class="boldFont">1rong> and rong class="boldFont">2rong> also have been discussed.
