Lamellar Alignment of Helical Polymers

Significance

Biological macromolecules and supramolecular assemblies such as polypeptides, DNA, and viruses suggest that rod-like helical polymers with well-defined structure are useful building blocks for self-assembled materials and nanoscale structures. Some monodisperse poly­peptides and viruses are known to form smectic liquid crystalline (LC) phases, but artificial helical polymers are generally too polydisperse to form highly ordered assemblies such as smectic (LC) phases. In this article, living polymerization of isocyanide L-1 with 2 as the initiator produced dia­stereomeric left- and right-handed helices with different molecular weights. The diastereomeric helices were separated by solvent fractionation with acetone, and narrow molecular weight distributions were found for each helical poly L-1. These polymers exhibit a lyotropic smectic LC phase in solution and form 2D smectic arrangements when cast from benzene solution onto highly oriented pyrolytic graphite by solvent evaporation.