SYNTHESES AND CHARACTERIZATION OF THE NOBLE-METAL SUBSTITUTED HEPTADECATUNGSTODIARSENATES

Four Dawson type heteropolyoxotungstates substituted by noble metals w ith tile general formula (TBA)(n)[As2W17M(OH2)O-61], where M=Pd-II, Ru -III, Ir-IV and Pt-IV are prepared by filling thp meant site of thp la cunary percursor alpha(2)-K10As2W17O61. UV-vis and IR spectra are simi lar to the other transition metal substituted Dawson type tungstodiars enates. EPR result provides direct evidence to identify the presence o f noble metal cation. Electrochemical behavior investigated bg cyclic voltammetry irt acetonitrile displays four reversible one-electron red ox couples attributed to the W(VI-->V) process of tungsten-oxo framewo rk.