ISSN:
0947-6539
Keywords:
crystal structure
;
NMR spectroscopy
;
proton transfer
;
pyrazoles
;
tautomerism
;
Chemistry
;
General Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
The crystal structure of the title compound was determined by X-ray analysis at 200 K. Three independent molecules form a trimer joined by strong and linear N-H … N hydrogen bonds. There is another centrosymmetrically related trimer in the unit cell. Both tautomers (1H and 2H) are present in each trimer. Disorder of the NH protons involved in the N-H … N hydrogen bonds has been observed. Solid-state 13C CPMAS NMR was used to establish the dynamic nature of the NH-proton disorder, the title compound being the first example of proton transfer in a tautomeric mixture of pyrazoles with an equilibrium constant other than 1.
Additional Material:
5 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/chem.19970030119
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