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Deuterium isotope effect on 13 C chemical shifts of tetrabutylammonium salts of Schiff bases amino acids
Author(s) -
Rozwadowski Z.
Publication year - 2006
Publication title -
magnetic resonance in chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.483
H-Index - 72
eISSN - 1097-458X
pISSN - 0749-1581
DOI - 10.1002/mrc.1852
Subject(s) - chemistry , deuterium , kinetic isotope effect , isotope , radiochemistry , deuterium nmr , organic chemistry , nuclear magnetic resonance spectroscopy , nuclear physics , physics
Deuterium isotope effects on 13 C chemical shift of tetrabutylammonium salts of Schiff bases, derivatives of amino acids (glycine, L ‐alanine, L ‐phenylalanine, L ‐valine, L ‐leucine, L ‐isoleucine and L ‐methionine) and various ortho‐hydroxyaldehydes in CDCl 3 have been measured. The results have shown that the tetrabutylammonium salts of the Schiff bases amino acids, being derivatives of 2‐hydroxynaphthaldehyde and 3,5‐dibromosalicylaldehyde, exist in the NH‐form, while in the derivatives of salicylaldehyde and 5‐bromosalicylaldehyde a proton transfer takes place. The interactions between COO − and NH groups stabilize the proton‐transferred form through a bifurcated intramolecular hydrogen bond. Copyright © 2006 John Wiley & Sons, Ltd.