(169a) Exploring Effective Design Strategies in Fine-Tuning the Electronic, Transport, and Photophysical Properties in Cofs

Covalent organic frameworks (COFs) have emerged as promising materials due to their highly tunable composition, structure, and physical properties, alongside their high porosity and large surface area. Despite their potential in gas separation, energy storage, catalysis, and optoelectronics, a unified understanding of the intricate relationship between composition, structure, intermolecular interactions, and electronic properties in COFs from an ab initio perspective remains elusive. Here, we present a systematic study that integrates multiple theoretical approaches, ranging from all-electron quantum chemistry to coarse-grained model Hamiltonians, specifically within the Density Functional Theory (DFT) and multi-particle Holstein formalism (MHF). Concretely, we find that functionalizing the linker with small functional groups in highly-symmetric lattices minimally alters the electronic structures, particularly when the backbone is dominant. Conversely, breaking symmetry in building blocks via functionalization, and if in turn leads to changes in lattice symmetry, proves to be an effective strategy for modulating electronic, transport, and photophysical properties. Our results provide physical insights as well as guiding principles for application-driven experimental discovery of novel COFs with enhanced photo-catalytic prowess. Finally, our methodology is an effective tool that enables disentangling the structure-property relationships in reticular materials.