Organodipalladium(II) cyclometallates of the schiff base N,N'-diethyl-2,6-dialdiminobenzene

Abstract

Syntheses and reactions of dipalladiobenzene derivatives have been reported. Li₂[PdCl₄] reacts with N,N'-diethyl-2,6- dialdiminobenzene (H₂L) to form the cyclometallated compound, [Pd₄L₂Cl₄], in which metallation occurs at the 3,5-carbon atoms of the aromatic ring. The tetrachloro compound can be converted to a dinuclear precursor complex, [Pd₂L(MeCN)₂(ClO₄)₂], which reacts with pyridine, 4-methylpyridine, pyrazole and imidazole (B) to produce complexes of the type [Pd₂L(B)₄](ClO₄)₂, and with 2,2'- bipyridine to produce [Pd₂L(bpy)₂](ClO₄)₂. A tetranuclear neutral complex [Pd₄L₂(pz)₄] is formed when the precursor complex interacts with pyrazole and triethylamine. A series of neutral chelate compounds [Pd₂L(AB)₂] has been obtained by reacting the precursor with sodium salts of acetylacetone, ethylacetoacetate, N-methylsalicylaldimine (HAB) and N,N'- dimethyldithiocarbamic acid (HAB). The compounds have been characterized from their ¹H NMR spectra.