Synthesis and structural characterization of binuclear palladium(II) complexes of salicylaldimine dithiosemicarbazones

Binuclear Pd(II) salicylaldiminato dithiosemicarbazone complexes were synthesized and characterized. The Pd complexes were obtained by the reaction of various ethylene- and phenylene-bridged dithiosemicarbazones with Pd(PPh3)2Cl2. The free salicylaldimine ligands and their Pd complexes were characterized by NMR and IR spectroscopies, ESI-mass spectrometry, elemental analyses and for two representative complexes also by x-ray diffraction. In both metal complexes, the solid-state structures show the two Pd centers to be coordinated in a slightly distorted square-planar geometry, which gives rise in each case to five- and six-membered chelate rings. The salicylaldimine thiosemicarbazone ligands coordinate to Pd in a tridentate manner, through the phenolic O, imine N and thiolate S atoms. [on SciFinder(R)]