Band topology is now considered to be as fundamental as band structure, underlying emergent quasiparticle phenomena such as robust edge states and spin-chain physics in organic systems (e.g. graphene nanoribbons), but the impact of topological band structures on the physics of excitons (i.e. a correlated electron-hole photo-excited state bound by Coulomb interaction) has only recently begun to attract widespread attention. Understanding and controlling the effects of topological phase transitions on the electronic and optical responses of materials could become a powerful tool for the design of novel optoelectronic devices and future quantum technologies, and this project will explore topological effects in an exciting new class of organic 1D materials using state-of-the-art theoretical simulation methods.