AN IMPROVED PREPARATION AND CHARACTERIZATION OF TETRAHEDRAL CO-II AND CO-III COMPLEXES WITH DODECATUNGSTATE AS THE TETRAHEDRAL LIGAND

Tetrabutylammonium salt of the 12-tungstoheteropolyanion with central Co**I**I as the heteroatom in a tetrahedral oxygen environment, left bracket Co**I**IW//1//2O//4//0 right bracket **6** minus , has been prepared by an improved manner. This manner remarkably shortens the total time needed for preparation, especially the time for purification, and gives a compound of a high purity. The corresponding Co**I**I**I compound has been obtained by oxidation with potassium peroxodisulfate from the potassium salt of the Co**I**I compound; its spectroscopic data (IR, near-infrared, UV-vis, and MCD) are presented.