Helix-Sense-Selective Precipitation Polymerization of Achiral Monomer for Preparing Optically Active Helical Polymer Particles

Abstract

Optically active polymer particles constitute a unique type of polymer particle. However, nearly all the particles of this kind so far reported in the literature were prepared from chiral monomers. On the other hand, helix-sense-selective polymerization (HSSP) techniques were majorly applied in solution polymerization systems for preparing helical polymers adopting predominant one-handed helicity. In the present study, we report the first HSSP in precipitation polymerization systems, by which optically active helical polymer particles were constructed from an achiral monomer. Achiral acetylenic monomer with bulky adamantyl group smoothly underwent helix-sense-selective precipitation polymerization (HSSPP) with (nbd)Rh+B–(C6H5)4 as catalyst in the presence of Boc-l- or Boc-d-alanine as chiral additive. The HSSPPs provided optically active polymer particles consisting of helical polymer forming predominantly one-handed screw sense. SEM images show that the resulting polymer particles were obtained in high y...