Abstract
The X-ray structure and the solid-state NMR measurements, mainly 15N CPMAS of the labelled compound, allow to determine the static and dynamic properties of 3(5)-ethyl-5(3)-phenyl-1H-pyrazole. The compound is a tetramer formed by three 5-ethyl-3-phenyl-1H-pyrazole and one 3-ethyl-5-phenyl-1H-pyrazole tautomers in dynamic equilibrium with the complementary situation.
Acknowledgements
We are indebted to the DGI/MCyT of Spain (Project no. BQU2003-00976) for financial support. This article is dedicated to our friend Professor Joaquin Plumet on his 60th anniversary.