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Proton transfer and secondary deuterium isotope effect in the 13C NMR spectra of ortho-aminomethyl phenols

✍ Scribed by M. Rospenk; A. Koll; L. Sobczyk

Publisher: Elsevier Science
Year: 1996
Tongue: English
Weight: 387 KB
Volume: 261
Category: Article
ISSN: 0009-2614
DOI: 10.1016/0009-2614(96)00956-6

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✦ Synopsis

The temperature dependence of the deuterium isotope effect on the t3c NMR signals for various positions in the phenyl ring of 2-(N,N-diethylaminomethyl) tetrachlorophenol was studied in the moderately polar solvent CH2C12. The critical temperature, T~ = 245 K, corresponds to the compensation of opposite effects for non-proton-transfer and proton-transfer (PT) forms existing in equilibrium. The UV spectra show that the contribution of the PT form at 245 K amounts to 20 5: 5%. Semi-empirical calculations taking into account the Onsager reaction field allowed us to discuss the role of permittivity and dimerization of polar PT forms in the charge separation.

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