Influence of Heterogeneity on the Chiral Expression of Star-Shaped Conjugated Polymers

In this report, the influence of heterogeneity on the chiral expression of star-shaped conjugated polymers is investigated. For this purpose, two heterogeneous star-shaped conjugated polymers, i.e., one with two chiral arms and one achiral arm and the other one with one chiral arm and two achiral arms, are synthesized by combining Kumada catalyst transfer condensative polymerization, efficient post-polymerization reactions, and a two-step click reaction. The supramolecular organization and chiral expression of these systems are investigated by combining UV–vis, circular dichroism, differential scanning calorimetry, and atomic force microscopy. Three different hypotheses concerning the (chiral) supramolecular organization are postulated, i.e. the sergeants-and-soldiers-like principle, the “defect effect”, and hampered organization. The results of the measurements exclude the first two hypotheses as a much lower chiral expression is obtained compared to the C3-symmetric chiral star-shaped polymer and revealed that replacing one chiral arm with one achiral arm was a too-large defect, resulting in a hampered organization.