Two new polyoxometalate-based hybrids consisting of Keggin-type cluster modified by {Ag4} group

• Two Keggin-type polyoxometalates consisting of {Ag4} clusters through weak Ag…Ag interactions have been synthesized.
• There exist face-to-face and dot-to-face π…π interactions in {Ag-ligand}4 fragment.
• The fluorescence properties of {Ag4} modified POMs are also discussed.

Two new supramolecular polyoxometalate compounds [Ag2(mbpy)3][Ag(mbpy)2][PW12O40] (1) and [Ag2(mbpy)3]2[SiW12O40] (2) (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 1–2 is in the cationic moiety of a tetra-core {Ag4} cluster through weak Ag…Ag interactions. The silver(I) centers show three-, four- and five-coordinated geometries. In 1 the tetrameric silver atoms in {[Ag2(mbpy)3]2}4+ covalently bind to [PW12O40]3− anion via Ag3O bonds, while there is only intermolecular hydrogen bonding between {[Ag2(mbpy)3]2}4+ and [SiW12O40]4− in 2. 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 1 and 2 also have been discussed.

New polyoxometalate-based hybrids consisting of Keggin-type clusters modified by {Ag4} groups had been synthesized and characterized, and their photoluminescence properties were also discussed. Figure optionsDownload as PowerPoint slide