Consecutive conformational transitions and deaggregation of multiple-helical poly(diacetylene)s

The polymerization of diacetylene macromonomers based on oligopeptide-polymer conjugates yields conjugated polymers with multiple-helical quaternary structures. These polymers exhibit a rich dynamic folding behavior upon the addition of protic cosolvents. Thus, a helix-helix transition under helix-sense inversion was followed by a reversible helix-coil transition. Both transitions involved changes in the aggregation state of the multiple-helical superstructures. The resemblance of the observed consecutive and cooperative conformational transitions to those of biopolymers underlines the importance of supramolecular self-assembly as a pathway toward biofunctional materials with optoelectronic activity.