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Association of p ‐toluyldimethylglycine in water
Author(s) -
Headley Allan D.,
Starnes Stephen D.
Publication year - 1999
Publication title -
journal of physical organic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.325
H-Index - 66
eISSN - 1099-1395
pISSN - 0894-3230
DOI - 10.1002/(sici)1099-1395(199904)12:4<290::aid-poc133>3.0.co;2-1
Subject(s) - chemistry , tautomer , hydrogen bond , aqueous solution , singlet state , proton nmr , molecule , computational chemistry , nmr spectra database , spectral line , medicinal chemistry , organic chemistry , physics , astronomy , nuclear physics , excited state
For an aqueous solution of p ‐toluyldimethylglycine [Me 2 NCH( p ‐CH 3 ‐C 6 H 4 )COOH], at low concentrations or high temperatures, where solute–solute interactions are minimal, inversion about the amino group and the rate of tautomerization are relatively fast on the NMR time‐scale. As a result, the dimethyl groups appear as a singlet in the NMR spectra. At high concentrations of the solute or low temperature, where there is an increase in solute–solute interactions via, more than likely, hydrogen bonds involving the acidic and basic functionalities, the rates of inversion and tautomerization are relatively slow. As a result, the two methyl groups are non‐equivalent on the NMR time‐scale. Copyright © 1999 John Wiley & Sons, Ltd.