COMPARATIVE-STUDY OF THE STRUCTURES OF SOME BASIC IRON(III) SULFATES

IR and EXAFS spectroscopies were used to study the products of the hyd rolysis of iron(lll) sulfate. A hypothesis for the structure of amorph ous basic iron sulfate is made from a comparison of its IR spectra and radial atomic distribution curves with the corresponding data for jar osite. Analysis of the interatomic distances and manifestations of the sulfate ion in the low- and high-temperature IR spectra shows that in the amorphous product of the hydrolysis, unlike in the jarosite, the sulfate ion is not involved in the first coordination sphere of the ir an atoms, but is held in the structure by hydrogen bonds. Reasons for the high catalyzing ability of the amorphous basic iron sulfate are su ggested.