1-Phenyl-3-methylpyrazol-2-in-5-thione, crystallised from methanol, was shown to exist in the tautomeric NH-form, stabilised by intermolecular NH···S hydrogen bonds. In solutions, however, the molecule is found predominantly ...

© 2001 Elsevier Science B.V. All rights reserved. It is shown that 1-phenyl-3-methyl-4-benzoylpyrazol-2-in-5-selenone exists in a SeH-tautomeric form in the solid phase. Crystal and molecular structure of bis(1-phenyl-3- ...