Optically Active Helical Polyacetylene@silica Hybrid Organic-inorganic Core/Shell Nanoparticles: Preparation and Application for Enantioselective Crystallization

This article reports on a novel category of hybrid nanoparticles (NPs) consisting of a unique organic core (composed of optically active helical polyacetylene) and an inorganic shell (composed of silica). The NPs were synthesized by combining in one system the aqueous catalytic microemulsion polymerization of substituted acetylene monomer to form the core and the sol gel approach of TEOS to form the shell. The substituted polyacetylene forming the core adopted helical conformations of predominant one handedness while the silica shell provided desirable protection for the core. The obtained emulsions exhibited high stability. The NPs possessed large optical activities, arising from the helical polymer chains constituting the core. The investigations are important in chemistry since two diverse research fields (organic helical polymers and inorganic materials) were combined for the first time in a specific system. The obtained hybrid core/shell NPs induced enantioselective crystallization of alanine enantiomers, attesting to the potential applications of the novel core/shell NPs.