Synthesis of New Silicon‐linked Lanthanocene Complexes and Their High Catalytic Activity for Methyl Methacrylate Polymerization with Nanometric Sodium Hydride as Co‐catalyst

Abstract

AbstractThe synthesis and characterization of four new silicon‐linked lanthanocene complexes with pendant phenyl groups on cyclopentadiene were reported. Based on the data of elemental analyses, MS and IR, the complexes were presumed to be unsolvated and dimeric complexes [Me2Si(C5H3CMe2C6H5)2LnCl]2 [Ln=Er (1), Gd (2), Sm (3), Dy (4)]. In conjunction with AlEt3 or sodium hydride as the co‐catalyst, these complexes could efficiently catalyze the polymerization of methyl methacrylate (MMA). When the nanometric sodium hydride was used as a co‐catalyst, the complexes were highly effective for the polymerization of MMA. At low temperature and in short time, in [Me2Si(C5H3CMe2C6H5)2LnCl]2/NaH (nanometric) system, the polymer was obtained in more than 80% yield and the molecular weight was greater than 105. The activity reached that of organolanthanide hydride as a single‐component catalyst. In [Me2Si(C5H3CMe2C6H5)2ErCl]2/NaH (nanometric) system, the effects of the molar ratio of MMA/catalyst and catalyst/co‐catalyst, and the temperature on polymerization were studied.