title: Design of Small Intramolecular Singlet Fission Chromophores: An Azaborine Candidate and General Small Size Effects.
abstract: We report the first attempt to design small intramolecular singlet fission chromophores, with the aid of quantum chemistry and explicitly simulating the time evolution of state populations using quantum dynamics method. We start with three previously proposed azaborine-substituted intermolecular singlet fission chromophores. Through analyzing their frontier orbital amplitudes, we select a BN-substituted azulene as the building block. Covalently connecting two such monomers and tuning their relative configuration, we examine three dimers. One dimer is found to be an eminent candidate: the triplet-pair state is quickly formed within 1 ps, and the two triplets are ready to be disentangled. We elucidate the general small size effects in intramolecular singlet fission and focus on specific aspects which should be taken care of when manipulating the fission rate through steric hindrance.
authors.affiliation: Department of Chemistry, Carleton University , Ottawa, Ontario K1S5B6, Canada.
authors.forename: Tao
authors.initials: T
authors.lastname: Zeng
authors.affiliation: Department of Chemistry, University of Waterloo , Waterloo, Ontario N2L3G1, Canada.
authors.forename: Prateek
authors.initials: P
authors.lastname: Goel