Hydrothermal Synthesis, Crystal Structure and Fluorescent Property of a Keggin Polyoxometalate [Cu~I(2,2'-bipy)_2]_3[PW~(VI)_(12)O_(40)]

A Keggin-type tungstohosphate compound [CuI(2,2?-bipy)2]3[PWVI12O40] 1 (bipy = bipyridine) was prepared by the hydrothermal method for the first time. Single-crystal X-ray diffraction revealed that 1 (C60H48Cu3N12O40PW12) crystallizes in the monoclinic system, space group P21/c with a = 16.9837(10), b = 17.9732(13) c = 27.8701(13) ?, β = 96.1039(10)o, V = 8459.2(9) ?3, Mr = 4004.89, Z = 4, Dc = 3.145 g/cm3, μ = 17.089 mm-1, F(000) = 7208, S = 1.005, the final R = 0.0469 and wR = 0.0827 for 10807 observed reflections (I 2σ(I)). Compound 1 consists of one discrete normal Keggin polyanion [PWVI12O40]3? and three isolated coordinated cat- ions [CuI(2,2?-bipy)2]+. Significantly, there exist three crystallographically independent asymmetric reduced copper (I) centers in 1. Furthermore, the compound shows strong photoluminescence property in solid state at room temperature.