THEORETICAL STUDY OF THE EXCHANGE ON TRANSITION METAL IONS CATALYZED LABELING OF O-IODOHIPPURIC ACID

The isotope exchange reaction of o-iodohippuric acid (OIHA) or o-iodo-benzoic acid (OIBA) with 125I,by using different metal ions (Cu2 * ,Ni2+,Co2 + , Fe2+) as catalyzed agents, is discussed theoretically by means of a quantum chemical method (SCF-MO, CNDO/2). The calculated saqueticc of stability of the complex compounds formed between the OIHA or OIBA with different metal ions is as follows. Cu2t>Ni2+ >Co2+ >Fe2+ .It is in agreement with that obtained by experimental method published before. The nature of the interaction of OIHA or OIBA with these matal ions is analyssd in the light of frontier orbital theory and double-atom energy(Ec-1).