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Determination of Δ H ≠ and Δ S ≠ by simultaneous 1 H and 13 C dynamic n.m.r. studies: Importance of the accuracy of temperature measurement
Author(s) -
PiccinniLeopardi C.,
Fabre O.,
Reisse J.
Publication year - 1976
Publication title -
organic magnetic resonance
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.483
H-Index - 72
eISSN - 1097-458X
pISSN - 0030-4921
DOI - 10.1002/mrc.1270080503
Subject(s) - analytical chemistry (journal) , physics , resonance (particle physics) , chemistry , atomic physics , nuclear physics , nuclear magnetic resonance , chromatography
From Δ G Tc ≠ values obtained by 1 H and 13 C dynamic nuclear magnetic resonance studies of the same dynamic process, it is possible to estimate Δ H ≠ and Δ S ≠ . Nevertheless, the accuracy of the temperature measurement is a factor which limits the applicability of this method. A very simple procedure for calibrating the usual temperature sensors is described, which can be applied to all types of n.m.r. probes. By the use of this procedure it is possible to measure coalescence temperatures in 1 H and 13 C n.m.r. with such an accuracy that Δ S ≠ can be effectively determined from the difference between Δ G Tc ≠ values.