Synthesis and structural characterization of zinc complexes supported by amino-benzotriazole phenoxide ligands: Efficient catalysts for ring-opening polymerization of e-caprolactone and β-butyrolactone

摘要

Two amino-benzotriazole phenol ligands, 2-(2H-benzotriazol-2-yl)-6-((diethylamino)methyl)-4-alkyl-phenol (alkyl = CH3, ~(C1DEA)BTP-H, and alkyl = C8H_(17), ~(C8DEA)BTP-H) were prepared through the Mannich condensation of 4-alkyl-2-(2H-benzotriazol-2-yl)phenol with the mixtures of excess paraformaldehyde and diethylamine under reflux conditions. Zinc complexes supported by amino-benzotriazole phenoxide ligands (~(C1DEA)BTP~- and ~(C8DEA)BTP") were synthesized and fully characterized. The reaction of ZnEt2 with ~(DEA)BTP-H (1 equiv.) produces the tetra-coordinated dimeric zinc complexes [(μ-~(C1DEA)BTP)ZnEt]2 (1) and [(μ-~(C8DEA)BTP)ZnEt]2 (2). Experimental results indicate that complex 1 catalyzes the ring-opening polymerization of e-caprolactone and β-butyrolactone with good catalytic activities in a controlled character.