On the solid state aggregation of chiral substituted poly(para-phenylene)s (PPPs)

We have investigated the chiroptical properties of a novel, chiral substituted PPP. The synthesis of poly(2,5-bis [2-(S)-methylbutoxy]-1,4-phenylene) (BMB-PPP) has been successfully achieved in a Suzuki-type aryl-aryl cross coupling. For our solid state CD studies we have investigated dropcasted and spincoated films. The films show high chiroptical anisotropies of the π-π* transition up to g=0.06 due to an intermolecular aggregation of single polymer chains. We have also succeeded in the generation of high-quality Langmuir-Blodgett (LB)-films. The LB-films with a preferred orientation in steeping direction do not display any CD activity.