Time Differential Perturbed Angular γγ-Correlation Studies of Diethylenetriaminepentaacetic Acid Complexes with $\text{}^{111}$In and $\text{}^{111m}$Cd

Static and dynamic electric quadrupole interactions of $\text{}^{111}$Cd in complexes with diethylenetriaminepentaacetic acid were studied by the time differential perturbed angular γγ-correlation technique using two parent isotopes, $\text{}^{111}$In(EC)$\text{}^{111}$Cd and $\text{}^{111 m}$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 $\text{}^{111}$Cd-diethylenetriaminepentaacetic-acid-complex in aqueous solutions at pH = 7.0 is characterised by the re-orientational correlation time of 7.7×10$\text{}^{-11}$ s and an electric field gradient V$\text{}_{zz}$=6.7(2)×10$\text{}^{21}$ V/m$\text{}^{2}$ with an asymmetry parameter η=0.75(5). A direct comparison of the electric quadrupole interaction parameters for diethylenetriaminepentaacetic- acid-complexes with $\text{}^{111}$In and $\text{}^{111m}$Cd confirmed the proposal about the fragmentation of the complexes caused by the after-effects of electron capture in $\text{}^{111}$In. An observed difference in the electric quadrupole interaction parameters obtained for the solutions with $\text{}^{111}$In and $\text{}^{111m}$Cd complexes reflects a process of a chemical rearrangement of the complex structure after the In decay into Cd