Reactions of cadmium(II) acetate with acetoacetanilide and methylacetoacetate thiosemicarbazones: A cyclization process leading to a pyrazolone - Themolecular and crystal structures of the free ligands and the complex [CdL2Py] (HL=2-[amino(thioxo)methyl]-5-methyl-2,3-dihydro-1H-3-pyrazolone, Py = pyridine)

Acetoacetanilide- and methylacetoacetate thiosemicarbazones (HTSC1 and HTSC 2, respectively) react with cadmium(II) acetate in methanol, giving complex es containing the ligand 2-[amino(thioxo)methyl]-5-methyl-2,3-dihydro-1H-3- pyrazolonate (L-). An X-ray diffraction study of the structures of HTSC1, H TSC2, HL, and [CdL2Py], identified the main structural changes in the cycli zation process. Additionally, the coordination of the metal in the complexe s [CdL(AcO)] . 2 MeOH and [CdL2] . 3 H2O was analyzed using IR spectroscopy in the solid state and H-1-, C-13- and Cd-113-NMR spectroscopy in solution . On reaction with aqueous trifluoroacetic acid, both complexes releases th e free pyrazolone, which can be easily isolated.