Singlet triplet-pair production and possible singlet-fission in carotenoids
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–...
| Main Authors: | , , , |
|---|---|
| Format: | Journal article |
| Language: | English |
| Published: |
American Chemical Society
2022
|
| _version_ | 1826309281402585088 |
|---|---|
| author | Manawadu, D Valentine, D Marcus, M Barford, W |
| author_facet | Manawadu, D Valentine, D Marcus, M Barford, W |
| author_sort | Manawadu, D |
| collection | OXFORD |
| description | 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 ∼50 fs with a yield of ∼60%. We further discuss whether this singlet triplet-pair state will undergo exothermic versus endothermic intra- or interchain singlet fission.
|
| first_indexed | 2024-03-07T07:31:51Z |
| format | Journal article |
| id | oxford-uuid:66d73b6f-17a3-4e2f-9920-8baaf8fb8dd4 |
| institution | University of Oxford |
| language | English |
| last_indexed | 2024-03-07T07:31:51Z |
| publishDate | 2022 |
| publisher | American Chemical Society |
| record_format | dspace |
| spelling | oxford-uuid:66d73b6f-17a3-4e2f-9920-8baaf8fb8dd42023-02-02T08:27:43ZSinglet triplet-pair production and possible singlet-fission in carotenoidsJournal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:66d73b6f-17a3-4e2f-9920-8baaf8fb8dd4EnglishSymplectic ElementsAmerican Chemical Society2022Manawadu, DValentine, DMarcus, MBarford, WInternal 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 ∼50 fs with a yield of ∼60%. We further discuss whether this singlet triplet-pair state will undergo exothermic versus endothermic intra- or interchain singlet fission. |
| spellingShingle | Manawadu, D Valentine, D Marcus, M Barford, W Singlet triplet-pair production and possible singlet-fission in carotenoids |
| title | Singlet triplet-pair production and possible singlet-fission in carotenoids |
| title_full | Singlet triplet-pair production and possible singlet-fission in carotenoids |
| title_fullStr | Singlet triplet-pair production and possible singlet-fission in carotenoids |
| title_full_unstemmed | Singlet triplet-pair production and possible singlet-fission in carotenoids |
| title_short | Singlet triplet-pair production and possible singlet-fission in carotenoids |
| title_sort | singlet triplet pair production and possible singlet fission in carotenoids |
| work_keys_str_mv | AT manawadud singlettripletpairproductionandpossiblesingletfissionincarotenoids AT valentined singlettripletpairproductionandpossiblesingletfissionincarotenoids AT marcusm singlettripletpairproductionandpossiblesingletfissionincarotenoids AT barfordw singlettripletpairproductionandpossiblesingletfissionincarotenoids |