Highly Syndiotactic Coordination (Co)polymerization of para-Methylselenostyrene

Abstract

Synthesis of selenium-containing syndiotactic polystyrene through coordination polymerization is difficult to achieve since selenium atoms usually poison the applied catalysts. Herein, we report the coordination polymerization of para-methylselenostyrene (pMSS) and its copolymerization with styrene (St) using pyridyl-methylene-fluorenyl-supported complexes [(Py–CH₂–Flu)Ln(CH₂SiMe₃)₂(THF)ₙ (Ln = Y (1), n = 1; Ln = Sc (2), n = 0)]. Complex 1 was completely inert, while complex 2 was highly active and exhibited >99% syndioselectivity to yield poly(pMSS) as the rare crystalline polymer-containing selenium atoms in side chains. In addition, the copolymerization of polar pMSS with nonpolar St under various pMSS-to-St ratios proceeded smoothly. The excellent syndiotacticity was maintained in the copolymerization, and the obtained copolymers have random sequence distributions confirmed by ¹³C NMR spectrum analysis and kinetics study. The optical performances of the copolymers with different incorporations of selenium were studied.