Rare-earth metal complexes derived from the acids Ph2C(X)CO2H (X= OH, NH2): Structural and ring opening polymerization (ROP) studies

Treatment of Ln(NO3)3.6H2O (Ln = La, Ce) with an equimolar amount 2,2′-diphenylglycine (DpgH) in ethanol afforded the corresponding hexacoordinated complexes (DpgH±)3Ln(NO3)3.H2O (DpgH± zwitterionic 2,2′-diphenylglycine, Ln La (1), Ce (2)). The spectroscopic and structural features these compounds have been investigated. Similar reactions related benzilic acid (BenzH2) were unsuccessful. catalytic behaviour 1 2 homo- copolymerization ε-caprolactone (ε-CL) rac-lactide (r-LA) has investigated herein. In case ε-CL, two exhibited comparable activity, allowing for complete monomer conversion under aerobic solvent-free conditions at 150 °C 24 h. With respect to ROP r-LA, was found be completely inactive, while only 8% achieved presence 2. Liquid oligomers isolated during ε-CL/r-LA co-polymerization both complexes. activity pre-ligands DpgH BenzH2 (i.e. metal-free) also examined. Interestingly, active, although it required a higher catalyst loading benzyl alcohol as co-activator.