Synthesis and Characterization of New Palladium(II) Complexes Containing N-Alkylamino-3,5-diphenylpyrazole Ligands. Crystal Structure of [PdCl(L2)](BF4) {L2=Bis[2-(3,5-diphenyl-1-pyrazolyl)ethyl]ethylamine}

In this paper, the synthesis of two new N,N', N ligands, bis[2-(3,5-diphenyl-1-pyrazolyl) ethyl] amine (L1) and bis[2-(3,5diphenyl-1-pyrazolyl) ethyl] ethylamine (L2) is reported. These ligands form complexes with the formula [PdCl(N,N',N)] Cl when reacting with [PdCl2(CH3CN)(2)] in a 1:1 metal-to-ligand molar ratio. Treatment of these ligands with [PdCl2(CH3CN)(2)] in a 1:1 metal-to-ligand molar ratio in the presence of AgBF4 or NaBF4 gave [PdCl(N,N',N)](BF4) complexes. These Pd-II complexes were characterized by elemental analyses, conductivity measurements, mass spectrometry, and IR, H-1, and C-13{H-1} NMR spectroscopies. The X-ray structure of the complex [PdCl(L2)](BF4) has been determined. The metal atom is coordinated by two azine nitrogen atoms and one amine nitrogen atom of the aminopyrazole ligand. The distorted square planar coordination is completed by one chlorine atom. In this complex, intermolecular pi-pi stacking interactions are present.