Journal of the American Chemical Society, Vol.123, No.33, 7978-7984, 2001
Self-assembly of folded m-phenylene ethynylene oligomers into helical columns
Circular dichroism spectroscopy has been used to study the self-assembly of two series of m-phenyleric ethynylene oligomers in highly polar solvents. The helical conformation of shorter oligomer lengths was found to be stabilized in aqueous acetonitrile solutions, while longer oligomers began to interact intermolecularly. The intermolecular aggregation of the oligomers in aqueous solutions revealed a chain length dependent association that required the presence of a stable helical conformation. Evidence for intermolecular interaction, is provided by Sergeants and Soldiers experiments in which the twist sense bias of a chiral oligomer is transferred to an achiral oligomer.