REACTION AND KINETICS IN SYSTEM OF RARE-EARTHS WITH P-HIPPUROCHLOROPHOSPHONAZO

The beta-type reactions, in which rare earth ions react with chloropho sphonazo reagents, are extremely sensitive and have been applied widel y to determination of rare earths. The reactions and kinetic behavior of the beta-type homo- and iso-nuclear chelates of rare earth with p-h ippurochlorophosphonazo (CPA-pHA) have been investigated by a spectrop hotometric method. Some kinetic parameters, such as the reaction rate constants, the half lives and the activation energies, were measured. The competing reactions between lanthanoid ions forming and non-formin g beta-type chelates were also studied. The effects and trends of diff erent organic solvents on the beta-type chelates have been discussed. A reaction mechanism of beta-type chelates has been proposed.