Molecular Tools to Tune Structure–Function Properties of π-Conjugated Organic Materials That Feature Perylene Diimide Units

Regulation of the structure–function relationships of π-conjugated supramolecular materials is of great importance to engineer organic optoelectronics equipped with remarkable excitonic and electronic properties. PDI is one of the keystone n-type building blocks with which to design diverse supramolecular polymers due to its excellent photophysical and redox properties. Only a handful of studies that allow modulation of structure–function relationships of PDI-based π-conjugated organic materials via redox stimulation, particularly in aqueous media, are known to date.

Chapter 1 provides an overview of the literatures on case studies based on supramolecular self-assembly of PDI-derived π-conjugated systems. 

In Chapter 2, we demonstrate that redox-assisted self-assembly is a promising approach to modulate the photophysical, redox, and morphological properties of PDI-based π-conjugated supramolecular polymers in aqueous media by tuning intermolecular electrostatic interactions. This strategy can offer new access to construct well-defined supramolecular architectures at kinetically trapped states with exceptional optoelectronic properties. 

In Chapter 3, we show that the photophysical, redox, and morphological properties of the redox-treated PDI-derived supramolecular polymers can be precisely tuned by varying the functional nature of the side chains.

In Chapter 4, by comparing different redox-assisted self-assembly processes, we demonstrate that in addition to the formation of n-doped PDI intermediates, the nature of sacrificial chemical reductants  can influence the structure–function properties of redox-treated assemblies of diverse PDI-based π-conjugated building blocks.

In Chapter 5, we describe our results on the investigation of ground-state electronic absorption, potentiometric and spectroelectrochemical properties of a novel PDI-based dimeric system. It provides fundamental insights to better understand how through-space electronic interaction may influence structural properties of neutral and n-doped states of PDI-dimer.