Hydrothermal synthesis and structure characterization of a novel [Cu1(dpq)2]+ complex cations modified arsenic-vanadium polyoxometalate [Cu(dpq)2]4[As8V14O42(H2O)] • 2H2O

A novel inorganic -organic hybrid compound [Cu(dpq)(2)](4)[As8V14O12(H2O)] center dot 2H(2)O(dpq = dipyrido[3,2-d:2',3'-f]quinoxaline) was synthesized under the hydrothermal condition and its structure was characterized via single-crystal X-ray diffraction, elemental analysis, IR and XPS spectra. The title compound crystallizes in a monoclinic crystal system, space group P2(1)/c with crystal parameters a = 1. 8973 ( 3) nm, b = 2.5816(2) nm, c = 2.8941(2) nm, beta = 106.61(2)degrees, V = 13.5846(12) nm(3), Z =4, R-1 =0. 0674, wR(2) = 0.1750. It possesses a spherical [As8V14O42 (H2O)](4-) cluster anion, four [ Cu-1 ( dpq)(2)](+) counter cations and two lattice water molecules. The cationic complexes form ca. 0.8 nm x 0.8 nm stellate channels along the c axis through strong pi center dot center dot center dot pi stacking interactions due to the multiple aryls in the dpq ligands. The polyoxoanions are embedded in the channels through extensive C-H center dot center dot center dot O short contact interactions.