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Raman, infrared and 13 C NMR studies on betaine–sulfamic acid (2:1) crystal and its hydrogen bonds
Author(s) -
Ilczyszyn Maria M.,
Ilczyszyn Marek
Publication year - 2003
Publication title -
journal of raman spectroscopy
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.748
H-Index - 110
eISSN - 1097-4555
pISSN - 0377-0486
DOI - 10.1002/jrs.1028
Subject(s) - betaine , raman spectroscopy , chemistry , hydrogen bond , carboxylate , magic angle spinning , infrared , sulfamic acid , crystallography , molecule , stereochemistry , nuclear magnetic resonance spectroscopy , organic chemistry , physics , optics
The betaine–sulfamic acid (2:1) crystal complex has been investigated by infrared and Raman experiments in polarized light and by cross‐polarization magic angle spinning 13 C NMR. Very short and symmetric hydrogen bonds formed by acidic protons and betaine carboxylate groups (—COO—H—OOC—) + are characterized by the Raman tensor α′(R) available from Raman symmetric stretching vibrations of the carboxylic groups and by the 13 C shielding tensor σ of these groups. The principal components of the both tensors were found as to be strongly related: σ ii = 93.12 + 0.125α′(R) ii . The sulfamate NH 2 group reorientation was characterized by Raman bandshape analysis at different temperatures. The energy of very weak O· · ·H—N—H· · ·O hydrogen bonds between the sulfamate and betaine moieties was characterized in this way. Copyright © 2003 John Wiley & Sons, Ltd.