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Application of 1 H NMR bi‐selective relaxation times to conformational analysis in solution
Author(s) -
Sugiura Makiko,
Takao Narao,
Fujiwara Hideaki
Publication year - 1988
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.1260261204
Subject(s) - chemistry , relaxation (psychology) , proton , pulse sequence , dipole , crystallography , proton nmr , spin–lattice relaxation , magnetic relaxation , nuclear magnetic resonance , stereochemistry , physics , psychology , social psychology , organic chemistry , quantum mechanics , magnetization , magnetic field
The usefulness of 1 H bi‐selective relaxation times ( T 1 BS ) and selective relaxation times ( T 1 s ) for structure and conformation determination is emphasized. A pulse sequence has been devised which provides the apparent observed T 1 BS . The cross‐relaxations (σ ij ) or F ij values are derived from the observed T 1 BSand T 1 Svalues. The σ ij values can be correlated with the HH distances ( r ij ) and can be used for conformational analysis or structure determination. The F ij values, which indicate the fractional contribution to the dipolar relaxation of proton i via the interaction with proton j ( i ≠ j ), can be compared with the NOE values. 2‐Vinylpyridine was chosen as a model compound and three types of T 1 values were measured for its protons. Its conformation in CDCl 3 solution is discussed based on the correlation between the σ ij obtained and the r ij values. A conformational equilibrium is suggested.