Chiral helical disubstituted polyacetylenes form optically active particles through precipitation polymerization†
Substantial progress has been made in preparing and applying particles constructed from monosubstituted polyacetylenes. For disubstituted acetylenes, however, it still remains a big academic challenge on how to prepare polymer particles from monomers, majorly due to the relevant polymerizations requiring water-sensitive metal catalysts. This article establishes the first protocol for preparing regular particles constructed from disubstituted polyacetylenes through precipitation polymerization. Two disubstituted acetylenic monomers underwent precipitation polymerization and the corresponding polymer particles with narrow size distribution were obtained smoothly. CD and UV-vis absorption spectra demonstrated that the disubstituted polyacetylenes forming optically active particles adopted chiral helical conformations. Effects of solvent composition and catalyst amount on the particles were studied in detail. A mechanism was then proposed for understanding the formation of particles. The study provides a universal, facile and straightforward way to prepare polymer particles from disubstituted polyacetylenes.