Analytical Chemistry and Spectroscopy
Wiley InterScience Backfile Collection 1832-2000
Chemistry and Pharmacology
1H and 133Cs NMR self-diffusion measurements were performed by means of the pulsed gradient spin-echo method (PGSE) to evaluate the complex formation constants of Cs and 18-crown-6 and those of Cs and some ethylene glycols in D2O. The calculated complex formation constants were checked as far as possible by using similar calculations based on relaxation data. Chemical shift measurements do not allow the evaluation of complex formation constants in these systems. A cross-check was introduced to verify the calculations based on the diffusion data. Similar investigations were performed on Na, K, Cs complexes and N-phenylaza-15-crown-5 in methanol. In this case, analysis of the diffusion data and as the relaxation rate and chemical shift data led to complex formation constants for 1:1 complexes, which is in contrast to a previous report suggesting the formation of 2:1 complexes.
Type of Medium: