Synthesis and characterization of two new inorganic–organic hybrid cobalt molybdenum(V) phosphates

Two new inorganic–organic hybrid cobalt phosphomolybdates (Hdien)2[Co(dien)]2[Co(dien)(H2O)]2[CoMo12O24(HPO4)2(H2PO4)2(PO4)4(OH)6] ··· 5H2O (1) and (H2dien)2[Co(dien)]2[Co(H2O)2]2[CoMo12O24(HPO4)4(PO4)4(OH)6] ··· 7H2O (2) (dien = diethylenetriamine), involving molybdenum in the V oxidation state and covalently bonded transition metal complexes, have been prepared under mild hydrothermal conditions and structurally characterized by elemental analyses, IR spectra, TG analyses, and single-crystal X-ray diffraction. Compound 1 exhibits a one-dimensional (1D) chain framework, in which dien molecules adopt two kinds of coordination modes. Compound 2 shows a two-dimensional (2D) layer framework with three types of unusual tunnels. To the best of our knowledge, it is the first time [Co(dien)] units are directly incorporated into 1D and 2D skeletons of reduced molybdenum phosphates. The electrochemical properties of the two compounds were studied via the method of bulk-modified carbon paste electrodes. Furthermore...