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Isotope effects on the O-17, H-1 coupling constant and the O-17-{H-1} nuclear Overhauser effect in waterстатья
Информация о цитировании статьи получена из
Web of Science,
Scopus
Статья опубликована в журнале из списка Web of Science и/или Scopus
Дата последнего поиска статьи во внешних источниках: 19 июля 2013 г.
- Авторы: Sergeyev N.M., Sergeyeva N.D., Raynes W.T.
- Журнал: Journal of Magnetic Resonance
- Том: 137
- Номер: 2
- Год издания: 1999
- Издательство: Academic Press
- Местоположение издательства: United States
- Первая страница: 311
- Последняя страница: 315
- DOI: 10.1006/jmre.1998.1682
- Аннотация: The NMR spectra of solutions of 30% O-17-enriched H2O and D2O in nitromethane display the resonances of the three isotopomers H2O, HDO, and D2O. All O-17, H-1 and O-17, H-2 coupling constants and the primary and secondary isotope effects on J(O-17, H-1) have been determined. The primary effect is -1.0 +/- 0.2 Hz and the secondary effect is -0.07 +/- 0.04 Hz. Using integrated intensities in the O-17 NMR spectra, the equilibrium constant for the reaction H2O + D2O reversible arrow 2HDO is found to be 3.68 +/- 0.2 at 343 K. From the relative integrated intensities of proton-coupled and -decoupled spectra the O-17-{H-1} NOE is estimated for the first time, resulting in values of 0.908 and 0.945 for H2O and HDO, respectively. This means that dipole-dipole interactions contribute about 2.5% to the overall O-17 relaxation rate in H2O dissolved in nitromethane. (C) 1999 Academic Press.
- Добавил в систему: Сергеев Николай Михайлович