Synthetic and spectroscopic aspects of tetraazamacrocyclic complexes of palladium(II)

Palladium(LI) complexes of the general composition [PdMacL]Cl-2 (MacL = macrocyclic ligand) containing 14-18 membered rings have been synthesized by the template condensation of the aliphatic diamines H2N(CH2)(n)NH2 (n = 2 or 3) with the dicarboxylic acids HOOC-(CH2)(m)-COOH (m = 1 or 2) in methanol. A square-planar environment of the ligand around the metal ion has been suggested on the basis of chemical analyses, infrared and H-1 NMR spectral studies, electronic spectra, molecular weight determinations and conductivity measurements. Spectroscopic studies confirm coordination of amide nitrogens to the central metal ion. The molar conductance values of the palladium(II) complexes show that they are 1:2 electrolytes.