Measurement of T2 spin-lattice relaxation times of 4-aminobenzo-15-crown-5 crown ether derivative doped with different ions, depending on temperature and concentration

In this study, the T2 relaxation times of the complexes obtained by doping with sodiumperchlorate (NaClO4) and lithiumperclorate (LiClO4) salts are measured by using a 400 MHz BRUKER NMR spectrometer.By taking into account of these measurement the binding constants ( ) are calculated according to the modified Benesi-Hildebrand equation and the chemical shift-method, respectively. Also, T2 spinSpin relaxation time of the crown ether solution held in fixed concentration and solved in aceton-d6 medium is measured depending on the temperature. It is observed that the T2 spin-Spin relaxaton time decreased linearly wiht respect to 1/T .When the result of binding constants obtained by Benesi-Hildebrand and the chemical shift_method are compared it is found that they are well-matched. The binding constants found here show that the crown ether which we used is complexed beter with the (NaClO4)ion, better.Furthermore the activation enerjies, Ea, and the affinity times and are calculated by evaluation of the plot of lnT2 versus 1/T. According to the results of these calculations, we can say that this mechanism comes from the rotational motion of the molecule.