Tyrosine Side-Chain Functionalities at Distinct Positions Determine the Chirooptical Properties and Supramolecular Structures of Pentameric Oligothiophenes.

Abstract

Control over the photophysical properties and molecular organization of π‐conjugated oligothiophenes is essential to their use in organic electronics. Herein we synthesized and characterized a variety of anionic pentameric oligothiophenes with different substitution patterns of L‐ or D‐tyrosine at distinct positions along the thiophene backbone. Spectroscopic, microscopic, and theoretical studies of L‐ or D‐tyrosine substituted pentameric oligothiophene conjugates revealed the formation of optically active π‐stacked self‐assembled aggregates under acid conditions. The distinct photophysical characteristics, as well as the supramolecular structures of the assemblies, were highly influenced by the positioning of the L‐ or D‐tyrosine moieties along the thiophene backbone. Overall, the obtained results clearly demonstrate how fundamental changes in the position of the enantiomeric side‐chain functionalities greatly affect the optical properties as well as the architecture of the self‐assembled supramolecular structures.