CRYSTAL STRUCTURE AND VIBRATIONAL SPECTRA OF M[VO2(SeO4)(H2O)2]•H2O (M = K, Rb, NH4)

By the hydration of MVO(SeO4)(2) with saturated water vapors at room temperature a series of isostructural complex compounds of vanadium(V) of the composition M[VO2(SeO4)(H2O)(2)]center dot H2O (K, Rb, NH4) are synthesized and their physicochemical properties are studied. Based on the X-ray and neutron diffraction data, it is found that their crystal structure is composed of VO6 octahedra linked in infinite chains by bridging SeO4 tetrahedra. Each of the VO6 octahedra has two short terminal V-O bonds forming a bent dioxovanadium group VO2+. Two water molecules are coordinated by vanadium and one molecule is out of the first coordination sphere in the interchain space. The vibrational spectra of the studied compounds are completely consistent with their structural features.