QUANTITATIVE EPR STUDIES OF TRANSITION-METAL IONS IN OXIDE, ALUMINOSILICATE AND POLYMER MATRICES

The importance of the proper choice of diamagnetic diluent used for pr eparation of standards for quantitative EPR measurements is shown by t he example of CuSO4 and VOSO4 standards. The results of determination of the stability of chemical composition of VOSO4-K2SO4 standards stor ed for various periods of time, performed by different analytical meth ods, are compared. The examples are given to illustrate application of quantitative EPR measurements in the studies of structure and propert ies of transition metal ions dispersed in various matrices. Changes in the coordination sphere of surface transition metal ions occurring up on adsorption of gas molecules, the degree of dispersion of these ions and the extent of M(n+)-M(n+) interactions derived from quantitative EPR measurements are described. The results of investigation of the me chanism of adsorption and catalytic reactions occurring on dispersed t ransition metal ions are presented.