In situ formation of Sm(III) initiator from SmI2/MMA for ring opening polymerization of cyclic esters

Sm(III) complex was generated in situ by one-electron transfer reaction of SmI2 with MMA. The resulting Sm(III) complex was tried as ring opening polymerization (ROP) initiator for cyclic esters like ε-caprolactone (CL). The polymers were obtained in high yield with low polydispersity index (1.1–1.2). The system was also used for the synthesis of block copolymers. Structural characterization of the resulting polymers was done using 1D (1H, 13C, 19F) and 2D (1H–13C heteronuclear multiple quantum correlation (HMQC) and heteronuclear multiple-bond correlation (HMBC)) NMR spectroscopic techniques.