Singlet Triplet-Pair Production and Possible Singlet-Fission in Carotenoids.

ABSTRACT: Internal conversion from the photoexcited state to a correlated singlet triplet-pair state is believed to be the precursor of singlet fission in carotenoids. We present numerical simulations of this process using a π-electron model that fully accounts for electron-electron interactions and electron-nuclear coupling. The time-evolution of the electrons is determined rigorously using the time-dependent density matrix renormalization group method, while the nuclei are evolved via the Ehrenfest equations of motion. We apply this to zeaxanthin, a carotenoid chain with 18 fully conjugated carbon atoms. We show that the internal conversion of the primary photoexcited state, S₂, to the singlet triplet-pair state occurs adiabatically via an avoided crossing within ∼5

SUBMITTER: Manawadu D 

PROVIDER: S-EPMC9084603 | biostudies-literature | 2022 Feb

REPOSITORIES: biostudies-literature