The structures of six N-unsubstituted pyrazoles, three already known and three newly synthesized, have been studied by a combination of X-ray crystallography, multinuclear NMR (solution and solid state), and density functional theory (DFT) calculations. In those cases where crystal structure and CPMAS NMR were available, the agreement was almost perfect, allowing a prediction of the tautomer (with certitude) and the tetrameric structure ( ...
