One inorganic-organic hybrid derived from reduced molybdophosphate and trinuclear cadmium(II) fragment

One new polyoxometalate (POM)-based inorganic-organic hybrid [Cd-3(II)(HPO4)(HPO4)(H2O)(2)]{Cd-II[P-4-Mo6O28H3.5(OH)(3)](2)}center dot(H(4)tpb)center dot 7H(2)O (1) (bpp = 1,3-bis-(4-pyridyl)propane, tpb = 1,2,4,5-tetra(4-pyridyl)benzene) constructed from reduced molybdophosphate [P4Mo6O28H3.5(OH)(3)](5.5-) (P4Mo6), trinuclear Cd-II-phosphate-Hbpp fragment and protonated tpb has been hydrothermally synthesized and structurally characterized by IR, elemental analyses and single crystal X-ray diffraction. The complex 1 crystallizes in the monoclinic system with the space group P2(1)/c and cell parameters of = 15.672(12) angstrom, b = 23.839(19) angstrom, c = 27.654(2) angstrom, beta = 115.850(10)degrees, V = 9297.9(12) angstrom(3), Z = 4, R-1 = 0.0534 and wR(2) = 0.1135. In complex 1, the P4Mo6 units are bridged by Cd-II ions to form the classic sandwich-type [Cd(P4Mo6)(2)] dimers, which are further connected into a two dimensional network via the trinuclear Cd-II subunits. The tpb is synthesized in situ from the bpp ligands and connects the adjacent 20 layers into a 3D supramolecular framework through hydrogen bonding interactions. The electrochemical and fluorescent properties of complex 1 have been investigated. (C) 2013 Xiu-Li Wang. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved.