Double helix formation of poly(m-phenylene)s bearing achiral oligo(ethylene oxide) pendants and transformation into an excess of one-handed single helix through cholate binding in water.

A water-soluble poly(m-phenylene) bearing an achiral oligo(ethylene oxide) chain at the 5-position was synthesized by the Ni(0)-mediated homo-coupling polycondensation of a 3,5-dibromophenol monomer. The poly(m-phenylene) adopted a single helical conformation in protic media and self-assembled into a double helix in water through aromatic interaction, while it took a random-coil conformation in chloroform. Upon the addition of sodium cholate in water, the double helical poly(m-phenylene) was transformed into single strands, which bound the cholate molecules to form an excess of one-handed single helix.