Furan‐Extended Helical Rylenes with Fjord Edge Topology and Tunable Optoelectronic Properties

Abstract

Lateral furan-expansion of polycyclic aromatics, which enables multiple O-doping and peripheral edge evolution of rylenes, is developed for the first time. Tetrafuranylperylene TPF-4CN and octafuranylquaterrylene OFQ-8CN were prepared as model compounds bearing unique fjord edge topology and helical conformations. Compared to TPF-4CN, the higher congener OFQ-8CN displays a largely red-shifted ( � 333 nm) and intensified absorption band (λ max = 829 nm) as well as a narrowed electrochemical band gap ( � 1.08 eV) due to its pronounced π-delocalization and emerging of open-shell diradicaloid upon the increase of fjord edge length. Moreover, strong circular dichroism signals in a broad range until 900 nm are observed for open-shell chiral OFQ-8CN, owing to the excellent conformational stability of its central bis(tetraoxa[5]helicene) fragments. Our studies provide insights into the relationships between edge topologies and (chir)optoelectronic properties for this novel type of O-doped PAHs.

Hetero-Polycyclic Aromatic Systems: A Data-Driven Investigation of Structure-Property Relationships

“…The incorporation of different atoms is a well-known strategy for modulating the frontier molecular orbitals of π-conjugated systems. For example, it has been empirically observed, and can also be rationalized with molecular orbitals-based considerations, that lone-pair bearing heteroatoms such as oxygen raise the HOMO level, 37,38 while boron lowers the LUMO level. 39 COMPAS-2 provides, for the first time, the possibility to substantiate these observations in a data-driven manner and, perhaps, to extract quantitative assessments of these effects.…”