Abstract: Reported here arc intramolecular process DNMR spectra of some diamagnctic complexes which were synthesized by the reaction of Cd、Hg、Pb and La with DTPA (dicthylcnelriamine pentaacetate), respectively. The rate constants and other thermodynamic parameters were obtained by complete line shape analysis. The intra molecular exchange process is also discussed in this paper, it was found that the activation energies of Cd、Hg and Pb-DTPA complexes are related to the size of the metal ions. The NMR spectrum of La-DTPA shows a double AB type in room temperature, but a single coalescent AB type as the temperature increases. it indicates that the △⇌Λ conversion and the N atom inversion are slow processes within the NMR lime scale.

Key words: DNMR, DTPA, Intramolecular processes