Supramolecular and structural modification on conformational by mixed ligand

A novel series of platinum(II) and palladium(II) complexes have been synthesized by template condensation of 4-methoxybenzaldehyde, benzaldehyde, 4-chlorobenzaldehyde and 4-nitrobenzaldehyde, with appropriate 4-aminoantipyrine (4-AAP) in the presence of K2PtCl4/PdCl2 to form complexes of the type [M(Ln)Cl2](where M = Pt(II) or Pd(II)). The corresponding Schiff base complexes mixed ligand were prepared by condensation of [M(Ln)Cl2] with ethanolamine (LH). The complexes have been characterized with the help of elemental analysis, IR, 1H and 13C NMR, electronic spectra, conductance measurements, magnetic susceptibilities and thermal analysis. On the basis of these studies, it is clear that ligands coordinated to metal atom in a mononuclear (NO) in (1–6), Schiff base complexes (NN*) in (7–9) and monobasic tridentate Schiff base complexes (NN*O) in (10–12). Thus, suitable square planar geometry for tetradentated state has been suggested for the metal complexes. Various ligand and nephelouxetic parameter have been calculated for the complexes. The thermal decomposition for complexes was studied.

The formation of [Pd(Ln)(L)Cl] shows that upon the addition of [Pd(Ln)Cl2] to a solution of LH, the ligand rearranges itself into the formation of an imine appended with Pd(II) and 4-derivatives benzaldehyde-4-aminoantipyrine (Ln).Figure optionsDownload as PowerPoint slideHighlights
► On the basis of these studies a square planar geometry has been proposed.
► The infrared data indicate the bidentate nature of ligands in all complexes.
► Molar conductance measurements indicated the complexes to be electrolytes.
► Various ligand and nephelouxetic parameter have been calculated for the complexes.
► The thermal decomposition for complexes was studied.