| The &agr;-Diimines (or) 1,4-diaza-1,3-butadienes (DAB) are neutral bidentate ligands which exhibit versatile coordination behavior with various transition and main group metals. These &agr;-diimine ligands can be conveniently prepared by condensation reactions involving glyoxals, &agr;-ketoaldehydes or diketones with primary alkyl or aryl amines (RNH2). The group 10 complexes of &agr;-diimine have attracted considerable interest in recent years as potential catalyst for polymerization reactions. Several transitional metal complexes of symmetrical &agr;-diimine have been prepared with general formula [ArN=C(R)C(R)=NAr] where ( R = H, alkyl, aryl, Ar = aryl). The catalytic activities of &agr;-diimine complexes depends on both substituents on nitrogen (Ar) and back-bone (R). However, &agr;-diimine ligands with unsymmetrical substituents are scarce, and could act as potential catalysts for olefin polymerization reactions. In present work, following unsymmetrical &agr;-diimine ligands [ArN=C(Et)C(Me)=NAr] (Ar = 2,6-( iPr)2C6H3), [ArN=C(Et)C(Me)=O] (Ar = 2,6-(iPr)2C6H 3), [Ar1N=C(Et)C(Me)=NAr2] (Ar1 = 2,6-( iPr)2C6H3), (Ar2 = 2,6 (CH3)2 C6H3) were synthesized by step by step condensation reactions. The coordination chemistry of these unsymmetrical &agr;-diimine ligands with group 10 metals like Ni, Pd and Pt were investigated in 1:1 reaction stoichiometry. |
