Synthesis of new palladium(II) compounds with several bidentate nitrogen-donor ligands: Structural analyses by 1H and 13C{ 1H} NMR spectroscopy and crystal structures

Abstract

The reaction of [PdCl 2(CH 3CN) 2] with N-alkylaminopyrazole ( NN′) ligands, 1-[2-(ethylamino)ethyl]-3,5-dimethylpyrazole ( deae), 1-[2-( i propylamino)ethyl]-3,5-dimethylpyrazole ( deai), and 1-[2-( t butylamino)ethyl]-3,5-dimethylpyrazole ( deat), affords a series of square planar Pd(II) complexes [PdCl 2( NN′)] ( NN′ = deae ( 1), deai ( 2) and deat ( 3)). The solid-state structures of complexes 1 and 3 were determined by single crystal X-ray diffraction studies. The NN′ ligands are coordinated through the N pz and N amine atoms to the metal atom, which completes its coordination with two chlorine atoms in a cis disposition. These palladium(II) compounds were characterised by elemental analyses, conductivity measurements, IR, 1H and 13C{ 1H} NMR spectroscopies. The NMR studies of the complexes prove the rigid conformation of the ligands when they are complexed.