Synthesis and two-dimensional correlation infrared spectroscopy study of an organic-inorganic hybrid compound constructed by [Mo(5)P(2)O(23)] and Cu-imidazole components.

A novel compound, (Himi)(H(3)O) Cu(imi)(2)[P(2)Mo(5)O(23)].H(2)O 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)A, b = 21.073(4)A, c = 16.664(3)A, Z = 4. It consists of the Mo-Cu building-blocks Cu(imi)(4)P(2)Mo(5)O(23), protonated imidazole cations and water molecules. In the Mo-Cu building-blocks, Mo(5)P(2)O(23) 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 Cu(2+) 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.