Journal article 364 views 36 downloads
Twisted Carotenoids Do Not Support Efficient Intramolecular Singlet Fission in the Orange Carotenoid Protein
,
James P. Pidgeon ,
Harrison Lee,
Matthew S. Proctor,
Andrew Hitchcock ,
Shuangqing Wang,
Dimitri Chekulaev,
Wing Chung Tsoi ,
Matthew P. Johnson,
C. Neil Hunter ,
Jenny Clark
The Journal of Physical Chemistry Letters, Volume: 14, Issue: 26, Pages: 6135 - 6142
Swansea University Authors:
Harrison Lee, Wing Chung Tsoi
-
PDF | Version of Record
© 2023, The Author(s). Published by American Chemical Society. Distributed under the terms of a Creative Commons Attribution 4.0 License (CC BY 4.0).
Download (2.22MB)
DOI (Published version): 10.1021/acs.jpclett.3c01139
Abstract
Singlet exciton fission is the spin-allowed generation of two triplet electronic excited states from a singlet state. Intramolecular singlet fission has been suggested to occur on individual carotenoid molecules within protein complexes provided that the conjugated backbone is twisted out of plane....
| Published in: | The Journal of Physical Chemistry Letters |
|---|---|
| ISSN: | 1948-7185 1948-7185 |
| Published: |
American Chemical Society (ACS)
2023
|
| Online Access: |
Check full text
|
| URI: | https://cronfa.swan.ac.uk/Record/cronfa63765 |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| Abstract: |
Singlet exciton fission is the spin-allowed generation of two triplet electronic excited states from a singlet state. Intramolecular singlet fission has been suggested to occur on individual carotenoid molecules within protein complexes provided that the conjugated backbone is twisted out of plane. However, this hypothesis has been forwarded only in protein complexes containing multiple carotenoids and bacteriochlorophylls in close contact. To test the hypothesis on twisted carotenoids in a “minimal” one-carotenoid system, we study the orange carotenoid protein (OCP). OCP exists in two forms: in its orange form (OCPo), the single bound carotenoid is twisted, whereas in its red form (OCPr), the carotenoid is planar. To enable room-temperature spectroscopy on canthaxanthin-binding OCPo and OCPr without laser-induced photoconversion, we trap them in a trehalose glass. Using transient absorption spectroscopy, we show that there is no evidence of long-lived triplet generation through intramolecular singlet fission despite the canthaxanthin twist in OCPo. |
|---|---|
| Keywords: |
Carotenoids, orange carotenoid protein, OCP, OCPo, OCPr, intramolecular singlet fission |
| College: |
Faculty of Science and Engineering |
| Funders: |
G.A.S. and C.N.H. acknowledge ERC Synergy Grant 854126. J.P.P. thanks the EPSRC for support through a Doctoral Training Partnership Scholarship (EP/R513313/1). The authors thank the EPSRC for a Capital Equipment Award (EP/L022613/1 and EP/R042802/1) which funded the Lord Porter Laser facility used in this study. J.C., C.N.H, G.A.S. and S.W. thank the EPSRC for funding through EP/S002103/1 and EP/T012455/1. J.C. and S.W. also thank the EPSRC for funding through EP/N014022/1. M.S.P. and M.P.J. were supported by Leverhulme Trust award RPG-2019-045. A.H. acknowledges The Royal Society (award URF\R1\191548). H.K.H.L. and W.C.T. acknowledge the SPECIFIC Innovation and Knowledge Centre (EP/N020863/1) grant for providing financial support. |
| Issue: |
26 |
| Start Page: |
6135 |
| End Page: |
6142 |