A series of novel organic-inorganic hybrids based on α-[AlW12O40]5- polyoxoanions and transition-metal organoamine complexes

A series of novel organic-inorganic assemblies, {Ag-3(2,2'-bipy)(2)(4,4'-bipy)(2)}{Ag(2,2'-bipy)(2)} {Ag(2,2'-bipy)}[AlW12O40]center dot H2O (1), [Ag(phen)(2)](3)[Ag(phen)(3)][AlW12O40]center dot H5O2 (2) and {Co(2,2'-bipy)(3)}(3){Co(H2O)(2,2'-bipy)(2)[AlW12O40]}(2)center dot H2O (3) (2,2'-bipy = 2,2'-bipyridine, 4,4'-bipy = 4,4'-bipyridine, phen = 1,10-phenanthroline) constructed from Keggin-type [AlW12O40](5-) polyoxoanion and transition-metal organoamine subunits, have been hydrothermally synthesized and characterized by elemental analysis, IR spectroscopy, thermal gravimetric analysis (TGA), electrochemical properties and single-crystal X-ray diffraction. A remarkable aspect of compound 1 is that there exists four types of coordination configurations for the five crystallographically independent Ag centers, and this phenomenon has never been observed in polyoxometalate (POM) chemistry. The trimeric {[Ag(phen)(2)](3)}(3+) cluster in compound 2 is firstly extended into an interesting one-dimensional wave-like array and then is further extended into a three-dimensional supramolecular network with the [AlW12O40](5-) clusters residing in the interstices of this three-dimensional framework. The most striking structure feature of compound 3 is that three water molecules linearly arrange between the adjacent monosupporting {Co(H2O)(2,2'-bipy)(2)[AlW12O40]}(3-) anions, leading to the formation of the three-dimensional supramolecular network by weak interactions.