Two novel polyoxotantalates formed by Lindqvist-type hexatantalate and Copper-amine complexes

Two novel polyoxotantalate derivatives, {[Cu(1,3-dap)(2)](2)[Cu(1,3-dap)(H2O)](2)[Ta6O19]}center dot 8H(2)O (1) and [Cu(en)(2)](4)[Ta(6)O19]center dot 14H(2)O (2) (1,3-dap= 1,3-diaminopropane, and en= ethylenediamine), which are constructed from the Lindqvist-type [Ta6O19](8-) anion and copper-amine complexes, have been synthesized and characterized by elemental analyses, IR, XPS, TGA and single-crystal X-ray diffraction. In compound 1, each [Ta6O19](8-) anion is bound to four copper fragments via the surface bridging oxygen atoms to form a neutral tetrasupported Lindqvist structure, which is further connected by water trimer via hydrogen-bonds to yield a one-dimensional (1D) supramolecular chain. In compound 2, the Ta6O19](8-) anions are linked together via the hydrogen bonds and Cu...O weak interaction to form an infinite 1D supramolecular chain, which is further connected to each other via hydrogen bonds with the cyclic water tetramer to yield a two-dimensional (2D) supramolecular network. (C) 2011 Elsevier B.V. All rights reserved.