Reactions of Cadmium(II) Acetate with Acetoacetanilide and Methylacetoacetate Thiosemicarbazones: A Cyclization Process Leading to a Pyrazolone – The Molecular and Crystal Structures of the Free Ligands and the Complex [CdL2Py] (HL = 2-[Amino(thioxo)methyl]-5-methyl-2,3-dihydro-1H-3-pyrazolone, P... (original) (raw)

2000, European Journal of Inorganic Chemistry

Keywords: Cadmium(II) pyrazolonates / Thiosemicarbazones / Cyclizations / 2-[Amino(thioxo)methyl]-3-pyrazolone / 1 H-, 13 C-, 113 Cd-NMR spectra Acetoacetanilide-and methylacetoacetate thiosemi-process. Additionally, the coordination of the metal in the complexes [CdL(AcO)] · 2 MeOH and [CdL 2 ] · 3 H 2 O was carbazones (HTSC 1 and HTSC 2 , respectively) react with cadmium(II) acetate in methanol, giving complexes analyzed using IR spectroscopy in the solid state and 1 H-, 13 C-, and 113 Cd-NMR spectroscopy in solution. On reaction containing the ligand 2-[amino(thioxo)methyl]-5-methyl-2,3dihydro-1H-3-pyrazolonate (L -). An X-ray diffraction study with aqueous trifluoroacetic acid, both complexes releases the free pyrazolone, which can be easily isolated. of the structures of HTSC 1 , HTSC 2 , HL, and [CdL 2 Py], identified the main structural changes in the cyclization Cadmium is an environmental pollutant of worldwide tained new Cd II compounds containing, in deprotonated form, the ligand 2-[amino(thioxo)methyl]-5-methyl-2,3-di-concern. In most studies of its interaction with natural or man-made chelating agents, the products, complexes with a hydro-1H-3-pyrazolone (HL, II). wide range of coordination spheres [1] and stabilities, have shown no regiochemical modification of the ligand. We report here two cases of complexation involving cyclization of the ligand.