Pyrazoles as molecular probes to study the properties of co-crystals by solid state NMR spectroscopy

摘要

Equimolar mixtures of 3,5-dimethylpyrazole (1) with four NH-imidazoles (2 - 5) have been studied by13 C and15 N CPMAS NMR and by DSC. In three cases, the solid mixture behaves as the sum of the individual components [imidazole (2), 2-methylimidazole (3) and 2,4(5)-dimethylimidazole (5)]. In one case [4,5-dimethylimidazole (4)], the mixture corresponds to a new species in which the dynamic behavior of 1 no longer exists.