Assembly of hexad-track Ag–N coordination polymeric chain-modified Keggin polyoxometalates

Two new organic–inorganic hybrid compounds based on the Keggin POMs modified by hexad-track Ag–N coordination polymeric chains, {[Ag(bipy)]3[HXW12O40]}[bipy] (X = Si 1, Ge 2) (bipy = 4,4′-bipyridine), have been hydrothermally synthesized and structurally characterized. Crystal data for compound 1: C40H33Ag3N8O40SiW12, triclinic, space group P-1, a = 11.369, b = 12.087, c = 13.110, α = 112.88, β = 94.43, γ = 99.49, V = 1617.2; for compound 2: C40H33Ag3N8O40SiW12, triclinic, space group P-1, a = 11.383, b = 12.119, c = 13.136, α = 112.95, β = 94.35, γ = 99.51, V = 1626.0. They represent important examples of the POM family which are modified by Ag complexes. By changing POMs, compound 3 (H2bipy)2[SiMo12O40] has been obtained, which exhibits a supramolecular structure. Their structural differences reveal that the abilities of oxidation of POMs play a major role in their modification of POMs by the transition metal Ag.

Graphical abstractBased on the Keggin POMs and Ag salt, three new compounds were obtained. Compounds 1 and 2 exhibit two novel 3D organic–inorganic hybrids with (4,6)-connected (41·64·81)(42·63·810) topology and compound 3 shows one supramolecular structure. Their successful isolation gives a good example for understanding the inter-relation between the POM chemistry and metal chemistry.Figure optionsDownload full-size imageDownload as PowerPoint slide