Substituent Effect on the Electronic Properties and Morphologies of Self‐Assembling Bisphenazine Derivatives

Abstract

Tuning electronic properties and morphologies: We report a unique design platform of n-type organic semiconductors based on asymmetrically substituted bisphenazines that enable tuning of both electronic properties and morphologies of 1D nanostructures (see figure) by using small substituents with various sizes and electronic demands.This paper reports the synthesis and characterization of novel self-assembling n-type organic semiconductors based on asymmetrically substituted bisphenazines with various functional groups of different size, electron-withdrawing ability, and conjugation length. The overarching objective of this research is to tune electronic properties and morphologies of self-assembled structures of this system simultaneously, which offers a potentially useful platform for future optoelectronic applications. The thermal, optical, and electrochemical properties associated with different substituents were studied by differential scanning calorimetry (DSC), UV-visible and fluorescence spectroscopy, and cyclic voltammetry (CV). Electronic properties were calculated using density functional theory, and results were compared to experimental HOMO, LUMO, and energy gaps. The one-dimensional (1D) self-assembly properties of these new n-type molecules are discussed in terms of the type of peripheral substituents, alkyl side group length, and assembly conditions. This study includes extensive investigations by scanning electron microscopy (SEM) and X-ray diffraction (XRD).