ALEXANDRINA FODOR, ANDA IOANA GRATIELA PETREHELE, SANDA RODICA BOTA, SIMONA BUNGAU HYDROTHERMAL SYNTHESIS AND COMPARATIVE STUDY OF TWO SILICIUM MONOLACUNAR POLYOXOMETALATES ZN COMPLEXES K7 . NH2O; (M=MO,W)
Two new monolacunar polyoxometalates Zn complex: K7 . nH2O; (M=Mo,W) were obtained by hydrothermal synthesis. The combination rate between ZnCl2 and heteropolyoxometalate ligand 9- and the optimal conditions for synthesis were determined by spectrophotometric and conduct metric methods. Elemental analyses, TG/DTA, IR, UV-VIS spectroscopy and X-ray diffraction methods were carried out. The IR and UV spectrophotometric methods reveal the conservation of the Keggin framework in the new monolacunar heteropolyoxometalate complexes. The thermo gravimetric and thermo differential curves confirmed that those two compounds are Keggin type. X-ray diffraction method shows that the monolacunar Keggin structure is isomorphic with other monolacunar Keggin heteropolyanions containing P as central atom and reveals an orthorhombic structure.