Metal complexes of pyrimidine-derived ligands. VII. Palladium(II), platinum(II) and rhodium(III) complexes with 3,5-dimethyl-1 -(4′, 6′-dimethyl-2′-pyrimidyl)pyrazole, a potential anti-cancer agent

Abstract Using 3,5-dimethyl-1-(4′,6′-dimethyl-2′-pyrimidyl)pyrazole (DPymPz) as a coordinating ligand, palladium(II), platinum(II) and rhodium(III) complexes of the type [M(DPymPz)X 2 ] (M = Pd(II), X = Cl, Br, I, SCN, ClO 4 , NO 2 , NO 3 ; M = Pt(II), X = Cl, Br, SCN, NO 2 ) and [Rh(DPymPz) 2 X 3 ] (X = Cl, Br, I) habe been isolated in the solid state and characterized on the basis of analytical, magnetic and spectral (diffuse reflectance, UV-Vis, IR and 1 H NMR) properties, together with powder X-ray diffraction studies. The Pd(II) and Pt(II)complexes are square-planar as expected and the Rh(III) species have pseudo-octahedral geometry. The calculated ligand field parameters are in favour of the proposed stereochemistry of the complexes. IR data point out the pyrazolyl nitrogen (tertiary) and one of the pyrimidyl nitrogens of DPymPz as bonding sites in forming these complexes.