Synthesis, X-ray crystal structure and NMR characterisation of mononuclear Pd(II) and Pt(II) complexes of didentate ligands with NN′-donor set

Two new 3,5-dimethylpyrazolic derived ligands that are N1-substituted by diamine chains, 1-[2-(diethylamino)ethyl]-3,5-dimethylpyrazole (L1) and 1-[ 2-(dioctylamino)ethyl]-3,5-dimethylpyrazole (L2) were synthesised. Reaction of the ligands, L1 and L2, with [MCl(2)(CH(3)CN)(2)] yielded [MCl(2)(L)] (M = Pd(II), Pt(II)) complexes. These complexes were characterised by elemental analyses, conductivity measurements, IR, (1)H, (13)C{(1)H} and (195)Pt{(1)H} NMR spectroscopies. The crystal structure of [PdCl(2)(L1)] was determined by single crystal X-ray diffraction methods. The structure consists of mononuclear units. The Pd( II) atom is coordinated by a pyrazolic nitrogen, an amine nitrogen and two chlorine atoms in a cis disposition. In this structure, C-H center dot center dot center dot Cl, C-H center dot center dot center dot H-C and C-H center dot center dot center dot C-H intermolecular interactions have been identified. (C) 2009 Elsevier B.V. All rights reserved.