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

Columnar mesogens constitute a fascinating class of supramolecular nano-architectures owing to the exceptional properties induced by their self-assembling behavior. Extending the pi-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) cm(2) 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.

Automated summary

In this study, a series of novel nitrogen and oxygen-incorporated chromenonaphthophenanthridine-based elliptical dimers were synthesized through tandem Pictet-Spengler cyclization followed by ipso-aromatic substitution in one-pot. Their mesophase characteristics were characterized by optical microscopy, differential scanning calorimetry, and X-ray diffraction studies. The photophysical properties were investigated using UV-vis and emission spectroscopy, and the charge transport properties were analyzed by time-of-flight measurements, with observed ambipolar mobilities of the order of 10(-3) cm(2) V-1 s(-1). These materials show promising potential for applications in organic electronics due to their high solubility, excellent thermal stability, self-organizing properties, and ambipolar charge transport characteristics.