Benzopyrano‐Fused Phenanthridine‐Based Columnar Mesogens: Synthesis, Self‐organization and Charge‐Transport Properties

Abstract

Columnar mesogens constitute a fascinating class of supramolecular nano‐architectures owing to the exceptional properties induced by their self‐assembling behavior. Extending the π‐conjugated core in such systems by incorporating heteroatoms extensively influences their mesomorphic, photophysical properties, etc., presenting them as potential candidates for optoelectronic applications. In the present work, a series of novel nitrogen and oxygen‐incorporated chromenonaphthophenanthridine‐based elliptical dimers have been synthesized through tandem Pictet‐Spengler cyclization followed by ipso‐aromatic substitution in one‐pot. Mesophase characterization has been carried out by employing POM, DSC, and X‐ray diffraction studies. Photophysical properties were investigated using UV‐vis and emission spectroscopy. Furthermore, the charge transport properties were analyzed by time‐of‐flight measurements, and the observed ambipolar mobilities were found to be of the order of 10−3 cm2 V−1 s−1. The high solubility, excellent thermal stability, self‐organizing properties, and ambipolar charge transport characteristics make them promising candidates for applications in organic electronics.