Aluminium complexes as catalysts for ring-opening polymerization of ϵ-caprolactone bearing Schiff base ligands derived from 4,4′-Methylenebis (2,6-diisopropylaniline)

Abstract

The mono and binuclear compounds, [4,4' methylene bis (2,6-diisopropylaniline) (3,5-di-Tert-butylsalicylaldehyde) AlEt2] (1), (2,6-diisopropylaniline) bis-(3,5-TBu2C6H2-O-2) AlEt2], obtained by reacting between triethyl-Aluminium and Schiff base derived from reaction of 4,4' methylene bis (2,6-diisopropylaniline with one and two equivalent of 3,5-Di-Tert-butylsalicylaldehyde to form L1H and L2H2 respectively. The reaction of L1H with triethyl aluminium lead to form monometallic complex, while L2H reacted with two equivalent of triethyl aluminium formed bimetallic complex (2). Both ligands and catalysts have been prepared and characterized by IR, 1HNMR and CHN analysis. The compounds 1 and 2 are investigated as catalysts for the polymerization of ϵ-caprolactone in the presence of benzyl alcohol. Both complexes showed moderate activity as pre-catalysts for ϵ-caprolactone polymerisation.