ISSN:
0749-1581
Keywords:
NMR
;
17O
;
Nd3+
;
Pr3+
;
Water exchange
;
Chemistry
;
Analytical Chemistry and Spectroscopy
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
17O NMR relaxation rate measurements were made on aqueous perchlorate solutions of the light lanthanide ions Nd3+ and Pr3+, with the aim of measuring the kinetics of water exchange on these ennea aqua ions. Variable-temperature results at three magnetic fields show that the ‘kinetic’ effect is not the only contribution to the difference between the transverse and longitudinal relaxation rates. The results at high magnetic field allow lower limits, kex298 ≥ 5 × 108 S-1 and kex298 ≥ 4 × 108 s-1, to be determined for water exchange rates at 298.15 K on [Nd(H2O)9]3+ and [Pr(H2O)9]3+, respectively. These limits are consistent with our current understanding of water exchange on the lanthanide aqua ions, based on the change of relative stability of the ennea and octa aqua ions across the series.
Additional Material:
5 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/mrc.1260321207
Permalink
