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Title: Intermolecular triple proton and deuteron transfer in crystalline 3,5-dimethylpyrazole studied by NMR, NQR, and x-ray methods

Abstract

A combination of {sup 13}C, {sup 15}N magnetic resonance, {sup 14}N quadrupole double resonance, and x-ray studies of solid 3,5-dimethylpyrazole between 270 and 350 K has shown that the NH...N hydrogen bond units present in the crystal are dynamically disordered, so that each nitrogen atom is on average attached to half a hydrogen atom. The molecules form discrete hydrogen-bonded cyclic trimers, in which the hydrogen atoms move in a double minimum potential energy surface which is symmetrical, to within experimental error. The experimental evidence in this temperature range is consistent with disorder by means of correlated triple hydrogen jumps with an activation energy of 45 kJ mol{sup {minus}1}. There is a large kinetic hydrogen (HHH)/deuterium (DDD) isotope effort of >20 at 299 K and equal to 8 at 347 K.

Authors:
; ;  [1];  [2];  [3]; ;  [4]; ; ;  [5]
  1. Universitaet Freiburg (West Germany)
  2. Instituto Rocasaolano, Madrid (Spain)
  3. C.S.I.C., Madrid (Spain)
  4. Universite Aix-Marseille III (France)
  5. King's College, London (England)
Publication Date:
OSTI Identifier:
6724815
Resource Type:
Journal Article
Journal Name:
Journal of the American Chemical Society; (USA)
Additional Journal Information:
Journal Volume: 111:19; Journal ID: ISSN 0002-7863
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; PYRAZOLES; CRYSTAL STRUCTURE; HYDROGEN TRANSFER; CALCULATION METHODS; CHEMICAL BONDS; DATA ANALYSIS; DEUTERON PROBES; EXPERIMENTAL DATA; MEASURING INSTRUMENTS; MEASURING METHODS; AZOLES; DATA; HETEROCYCLIC COMPOUNDS; INFORMATION; NUMERICAL DATA; ORGANIC COMPOUNDS; ORGANIC NITROGEN COMPOUNDS; PROBES; 400201* - Chemical & Physicochemical Properties

Citation Formats

Wehrle, B, Aguilar-Parrilla, F, Limbach, H H, de la Concepcion Foces-Foces, M., Cano, F H, Elguero, J, Baldy, A, Pierrot, M, Khurshid, M M.T., Larcombe-McDouall, J B, and Smith, J A.S. Intermolecular triple proton and deuteron transfer in crystalline 3,5-dimethylpyrazole studied by NMR, NQR, and x-ray methods. United States: N. p., 1989. Web.
Wehrle, B, Aguilar-Parrilla, F, Limbach, H H, de la Concepcion Foces-Foces, M., Cano, F H, Elguero, J, Baldy, A, Pierrot, M, Khurshid, M M.T., Larcombe-McDouall, J B, & Smith, J A.S. Intermolecular triple proton and deuteron transfer in crystalline 3,5-dimethylpyrazole studied by NMR, NQR, and x-ray methods. United States.
Wehrle, B, Aguilar-Parrilla, F, Limbach, H H, de la Concepcion Foces-Foces, M., Cano, F H, Elguero, J, Baldy, A, Pierrot, M, Khurshid, M M.T., Larcombe-McDouall, J B, and Smith, J A.S. 1989. "Intermolecular triple proton and deuteron transfer in crystalline 3,5-dimethylpyrazole studied by NMR, NQR, and x-ray methods". United States.
@article{osti_6724815,
title = {Intermolecular triple proton and deuteron transfer in crystalline 3,5-dimethylpyrazole studied by NMR, NQR, and x-ray methods},
author = {Wehrle, B and Aguilar-Parrilla, F and Limbach, H H and de la Concepcion Foces-Foces, M. and Cano, F H and Elguero, J and Baldy, A and Pierrot, M and Khurshid, M M.T. and Larcombe-McDouall, J B and Smith, J A.S.},
abstractNote = {A combination of {sup 13}C, {sup 15}N magnetic resonance, {sup 14}N quadrupole double resonance, and x-ray studies of solid 3,5-dimethylpyrazole between 270 and 350 K has shown that the NH...N hydrogen bond units present in the crystal are dynamically disordered, so that each nitrogen atom is on average attached to half a hydrogen atom. The molecules form discrete hydrogen-bonded cyclic trimers, in which the hydrogen atoms move in a double minimum potential energy surface which is symmetrical, to within experimental error. The experimental evidence in this temperature range is consistent with disorder by means of correlated triple hydrogen jumps with an activation energy of 45 kJ mol{sup {minus}1}. There is a large kinetic hydrogen (HHH)/deuterium (DDD) isotope effort of >20 at 299 K and equal to 8 at 347 K.},
doi = {},
url = {https://www.osti.gov/biblio/6724815}, journal = {Journal of the American Chemical Society; (USA)},
issn = {0002-7863},
number = ,
volume = 111:19,
place = {United States},
year = {Wed Sep 13 00:00:00 EDT 1989},
month = {Wed Sep 13 00:00:00 EDT 1989}
}