Microspheres Consisting of Optically Active Helical Substituted Polyacetylenes: Preparation via Suspension Polymerization and Their Chiral Recognition/Release Properties

Abstract

Cross-linked microspheres consisting of optically active helical substituted polyacetylenes are reported. For preparing the microspheres, substituted polyacetylene copolymers with pendent polymerizable CC bonds are first prepared and then used as macromonomers to copolymerize with acrylates via suspension polymerization, providing cross-linked microspheres. The helical polymer segments render the microspheres with optical activity, whereas the acrylate-based polymers afford the swelling property. CD and UV-vis spectra demonstrate the optical activity of the microspheres. The microspheres preferably adsorb (R)-(+)-1-phenylethylamine, (R)-(+)-N-benzyl-1-phenylethylamine, and Boc-D-alanine, whereas released Boc-L-alanine rather more rapidly than its enantiomer.

The First Suspension Polymerization for Preparing Optically Active Microparticles Purely Constructed from Chirally Helical Substituted Polyacetylenes

“…According to the strategy shown in Scheme , four kinds of MPs were prepared, namely non‐crosslinked and crosslinked MPs fabricated from poly1 (the polymer of M1) and poly2 (the polymer of M2), respectively. All of these MPs exhibited a yellow color, which is in accordance with earlier reports and originates from the helical substituted polyacetylenes …”

“…The crosslinked poly1‐MPs were also expected to exhibit optical activity. In this case, the CD and UV‐vis spectra were measured as follows . A certain amount of the MPs were immersed in chloroform (or THF) for a given time to remove the soluble part, if any.…”

“…Based on our earlier studies concerning optically active particles derived from helical substituted polyacetylenes, in the present study we prepared, for the first time via suspension polymerization, a new class of OAMPs (of μm size) solely constructed from helical substituted polyacetylenes. Compared to the nanoscaled ones previously prepared via emulsion and precipitation polymerizations, the microscaled particles demonstrated some advantages, in particular relating to preparation and ease of separation.…”

“…Among the abundance of conjugated polymers, polyfluorenes, polypyrroles, polycarbazoles, polythiophenes, and polyanilines have been successfully prepared in the form of MPs, while substituted acetylenes have regrettably been left behind, although they are widely recognized as typical conjugated polymers with a relatively long history. Moreover, even the previously prepared MPs consisting of substituted polyacetylenes from our group were all composite ones (vinyl polymers were present) rather than pure microspheric architectures solely constructed from polyacetylene chains. It is therefore still an essential challenge to prepare particles exclusively constructed from polyacetylene and its derivatives on the microscale.…”

Chiral, pH-sensitive polyacrylamide hydrogels: Preparation and enantio-differentiating release ability

“…We prepared chiral polymer microspheres [20,21] and chiral polymer amphiphilic networks [22] in our previous studies, and all these materials with optical activity showed chiral recognition and enantioselective release ability. Based on these studies, we in the present study designed and prepared a new kind of chiral hydrogels by copolymerization of chiral hydrophilic monomer N-acryloyl-Lalanine (NAA) and hydrophobic monomer octadecyl acrylate (C18), with N,N 0 -methylenebisacrylamide (BIS) as crosslinking agent.…”