Synthesis, Characterization And Catalytic Activity Towards Ring-Openging Polymerization Of ε-Caprolactone Of Dimethyl Aluminum Complexes Bearing Tetradentate Pyrrole Containing Ligands

Condensation of 5-tert-butylpyrrole-2-carbaldehyde with varied diamines ( o-phenylenediamine, propylenediamine, ethylenediamine ) led to the formation of R[N = CH-2-(5-t-Bu-Pyrrole)]2( R = o-C6H4, H2L1, 1; 1,3-(CH2) 3, H2L2, 2; 1,2-(CH2) , H2L,3 3, respectively ). Treatment of HL , HL and HL with 3 equiv of AlMe3(excess) generated bimetallic dimethylaluminum complexes ( L1(AlMe2) 2,4; L(AlMe2) 2, 5; L3AlMe2 2, 6 ) respectively. Compounds 1-6 were characterized by 1HNMR and their uv-vis spectroscopy. The molecular structure of 4 was determined by X-ray single crystal diffraction analysis. Compounds 4 and 6 are initiators for ring-opening polymerization of s-caprolactone.