Influence of Position Isomerism on the Chiral Properties in Sequence-Defined Conjugated Macromolecules

The chiral expression in conjugated polymers (CPs) has garnered significant attention, particularly due to its dependence on the aggregation process. Many variables that influence the chiral response have been investigated; however, achieving absolute control over the primary structure remains challenging. In this study, an orthogonal approach is used to develop sequence-defined conjugated macromolecules with precise control over monomer sequence and primary structure. The influence of position isomers is investigated by synthesizing four enantiomeric co-oligomers, composed of two chiral monomers out of nine. Solvatochromism experiments, using ultraviolet-visible (UV-vis) and circular dichroism (CD) experiments, are conducted to examine the chiroptical response. This study investigates not only the monomer position but also the role of (a)symmetry along with the concentration dependence to determine whether an inter- or intramolecular process occurs. These findings provide valuable insights into controlling the chiroptical properties of CPs, paving the way for improved materials design for optoelectronic applications.