Synthesis of a bis(diketiminate)bromosamarium(III) complex and its activity in the polymerization of methyl methacrylate

A bis(diketiminate)bromosamarium(III) complex was successfully synthesized and, after the activation with butyl lithium, was shown to be active in methyl methacrylate (MMA) polymerization. The effects of temperature, polymerization time and catalyst concentration were studied. Activities of ca. 16,000 g of poly(methyl methacrylate) (PMMA) per mol of samarium and per hour were obtained under optimum conditions (0 °C and a MMA/catalyst molar ratio of 90/1), providing a polymer with a molar mass Mn > 23.0 kg mol−1 and a molar mass distribution (Mw/Mn) < 1.4. After 1 h of polymerization, conversions of MMA as high as 90% were observed.

Graphical abstractBis(diketiminate)bromosamarium(III) was synthesized and shown to be active in the polymerization of methyl methacrylate. The catalyst shows in the first 30 min an activity of 20.2 kg PMMA (mol Sm)−1 h−1, giving a polymer with a molar mass Mn > 23.0 kg mol−1 and molar mass distribution (Mw/Mn) < 1.4. Figure optionsDownload full-size imageDownload as PowerPoint slide