ISSN:
0030-4921
Keywords:
Chemistry
;
Analytical Chemistry and Spectroscopy
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
Temperature dependences of the paramagnetic shifts induced by Eu(fod)3 in 1H NMR spectra of ethylene oxide in carbon disulphide solution are obtained in the temperature range from +40 to - 100°C at 100 MHz and from +30 to -60°C at 60 MHz. The influence of chemical exchange leads to a decrease of the observed paramagnetic shifts with decreasing temperature. It is shown that a modified Swift and Connick equation can be used to describe the observed dependences. Upper limits of the mean lifetimes of the Eu(fod)3-ethylene oxide adduct are τp 〈 1·7 × 10-8 s at 14 °C and τp 〈 1 × 10-8 s at 20 °C, respectively. The corresponding activation energy is equal to Va = 13·7 kcal/mol.
Additional Material:
2 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/mrc.1270071002
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