NEW HETEROPOLYOXOTUNGSTATE CONTAINING RH(III) AND NI(II) .2. CHARACTERIZATION BY STUDIES IN SOLUTION

The present paper reports the results of the interpretation of UV and visible absorption spectra of the anion [Ni(H2O)RhW11O39](7-) and the behavior of this heteropolyoxotungstate towards the Amberlite IR-120 i n the H+ form, The interpretation of the visible absorption spectra re vealed that Ni(II) is octahedrally coordinated From the UV and visible absorption spectra and from the behavior of the heteropolyanion in ac idic medium indirect evidence has been obtained for the tetrahedral co ordination of Rh(III) and for the formulation of the anion with Rh(III ) as central atom, respectively. By treatment with a H+ form ion excha nger the acid H-5[RhW12O40] has been obtained.