Deuterium isotope effect on 13C chemical shifts of tetrabutylammonium salts of Schiff bases amino acids.
Deuterium isotope effects on 13C 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 CDCl3 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.
Rozwadowski
Z
Z
Institute of Chemistry and Environmental Protection, Szczecin University of Technology, Al. Piastów 42, 70-065 Szczecin, Poland. zroz@ps.pl
D000447:Aldehydes / Q000737:chemistry*; D000596:Amino Acids / Q000737:chemistry*; D001547:Benzaldehydes / Q000737:chemistry*; D002247:Carbon Isotopes / Q000032:analysis; D003903:Deuterium / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D009281:Naphthalenes / Q000737:chemistry*; D000644:Quaternary Ammonium Compounds / Q000737:chemistry*; D012492:Salts / Q000737:chemistry; D012545:Schiff Bases / Q000737:chemistry
C482304:2-hydroxynaphthaldehyde; D000447:Aldehydes; D000596:Amino Acids; D001547:Benzaldehydes; D002247:Carbon Isotopes; D009281:Naphthalenes; D000644:Quaternary Ammonium Compounds; D012492:Salts; D012545:Schiff Bases; C032892:3,5-dibromosalicylaldehyde; D003903:Deuterium; C009405:tetrabutylammonium