Functionalization of Coordination Nanochannels for Controlling Tacticity in Radical Vinyl Polymerization

摘要

Systematic functionalization of porous coordination polymers (PCPs), [Cu2(L)2(ted)]n (wherenL ) dicarboxylates and ted ) triethylenediamine), by introducing various substituents onto the componentnorganic ligand, L, was performed to regulate the radical polymerization of methyl methacrylate (MMA) innthe nanochannels. The effect of the substituent groups on stereoregularity of the resulting poly(methylnmethacrylate) (PMMA) was observed, where the tacticity of the PMMA strongly depended on the numbernand position of the substituent. In particular, polymerization of MMA in [Cu2(2,5-ndimethoxyterephthalate)2(ted)]n gave PMMA with high isotactic and heterotactic triad fractions, which isnone of the most effective systems for changing the tacticity of PMMA in radical polymerization. To understandnthe mechanism of this drastic stereoregularity change, a variety of experimental and theoretical analyses,nsuch as IR, N2 adsorption, a statics study, and molecular dynamics (MD) calculations, were performed.nAccurate MD calculations were helpful to determine the most plausible structures of [Cu2(L)2(ted)]n andnrevealed that the specific channel shape of [Cu2(2,5-dimethoxyterephthalate)2(ted)]n induces the large tacticitynchange of the resulting PMMA.