Synthesis and two-dimensional correlation infrared spectroscopy study of an organic-inorganic hybrid compound constructed by [Mo5P2O23] and Cu-imidazole components

A novel compound, (Himi)(H3O) [Cu(imi)(2)](2) [P2Mo5O23](H2O)-H-. 1 (imi = imidazole), was synthesized by hydrothermal method and characterized by X-ray single analysis, ESR spectrum, one-dimensional (1D) infrared spectroscopy and two-dimensional (2D) correlation infrared spectroscopy under thermal and magnetism perturbation. Crystal data for the compound 1: orthorhombic system, space group Pnma, a = 14.580(3) angstrom, b = 21.073(4) angstrom, c = 16.664(3) angstrom, Z = 4. It consists of the Mo-Cu building-blocks [Cu(imi)(4)](2)[P2Mo5O23](2-), protonated imidazole cations and water molecules. In the Mo-Cu building-blocks, [Mo5P2O23](6-) clusters are linked by {Cu(imi)(4)}(2+) group to form a two-dimension parallelogram griddling structure. From the 2D IR correlation spectroscopy analyses, it is discovered that the intensity changes of Mo = O and P-O band are sensitive to the temperature variation, whereas the Mo-O bond linking to Cu2+. can be remarkably affected by the magnetism variation. Furthermore, the intensity changes of P-O bands occur prior to that of the Mo = O band during the temperature elevation. (c) 2005 Elsevier B.V. All rights reserved.