Abstract: The dynamic NMR investigation of Zn, Mg, Pb and Hg binuclear complexes with TTHA(triethylene-tetraaminhexaacetic acid) is reported in this paper,The intramolecular rearrangement of Zn₂TTHA is observed in the range of the temperature studied and the rate constants of the rearrangement process are calculated by the simulating to the experimental spectra.It is suggested that the structural units of Zn₂TTHA are two octahedral units but not two tetrahedral ones; the activation energies E_aof the binuclear complexes of Mg, Pb and Hg with TTHA are estimated by the Bloch equation of the two sites exchange; and the order of E_ais linearly related to the ion potential of the metal ions.

Key words: Zn₂TTHA, Dynamic NMR, Intramolecular rearrangement