A DFT study on ring-opening polymerization of ε-caprolactone initiated by Mg and Al complexes

The ring-opening polymerization (ROP) of ε-caprolactone (CL) initiated by the Mg and Al complexes was studied using density functional theory (DFT) calculation. The calculated results indicate that the Al complexes tend to activate the CO double bond of CL firstly, and that the Mg complexes tend to activate the CO single bond of CL instead. The Al complexes with PhCH2O− (OBn) group are more reactive than that with Me group in the chain initiation reaction of ROP of CL. For the Mg complexes, the addition of BnOH has no effect on the activity of the Mg complexes, which is in good agreement with experimental results.