Time Differential Perturbed Angularγγ-Correlation Studies of Diethylenetriaminepentaacetic Acid Complexes with ^{111}In and ^{111m}Cd

Static and dynamic electric quadrupole interactions of 1 1 1 Cd in complexes with diethylenetriaminepentaacetic acid were studied by the time differential perturbed angular γγ-correlation technique using two parent isotopes, 1 1 1 In(EC) 1 1 1 Cd and 1 1 1 m Cd. The measurements were carried out using neutral aqueous solutions of the diethylenetriaminepentaacetic-acid-complexes with initial isotopes at 293 K and 77 K. It was shown that the 1 1 1 Cd-diethylenetriaminepentaacetic-acid-complex in aqueous solutions at pH = 7.0 is characterised by the re-orientational correlation time of 7.7 x 10 - 1 1 s and an electric field gradient V z z = 6.7(2) × 10 2 1 V/m 2 with an asymmetry parameter η = 0.75(5). A direct comparison of the electric quadrupole interaction parameters for diethylenetriaminepentaacetic- acid-complexes with 1 1 1 In and 1 1 1 m Cd confirmed the proposal about the fragmentation of the complexes caused by the after-effects of electron capture in 1 1 1 In. An observed difference in the electric quadrupole interaction parameters obtained for the solutions with 1 1 1 In and 1 1 1 m Cd complexes reflects a process of a chemical rearrangement of the complex structure after the In decay into Cd.