ERROR 1
ERROR 1
ERROR 2
ERROR 2
ERROR 2
ERROR 2
ERROR 2
Password and Confirm password must match.
If you have an ACS member number, please enter it here so we can link this account to your membership. (optional)
ERROR 2
ACS values your privacy. By submitting your information, you are gaining access to C&EN and subscribing to our weekly newsletter. We use the information you provide to make your reading experience better, and we will never sell your data to third party members.
By bending a linear chain of porphyrin units into a molecular ring, researchers have mimicked a key structure that enables photosynthesis in purple bacteria (Nat. Chem. 2022, DOI: 10.1038/s41557-022-01032-w).
The natural light-harvesting system LH2 contains two concentric rings of bacteriochlorophyll molecules, each about 6 nm wide, which absorb sunlight and rapidly funnel the energy to a reaction center. Although the chlorophylls are not directly connected, proteins hold them very close together, and they can channel a cascade of energy in less than 200 fs.
Chemists have made various synthetic rings of porphyrins that serve as models for LH2, but most of them transport energy in a different way—or much more slowly—than the natural versions.
A team led by Harry L. Anderson at the University of Oxford has now created a closer mimic from a chain of 24 porphyrins, capped at either end by alkynes. A pair of asterisk-shaped template molecules bends the chain into a circle, before a palladium catalyst links the alkynes to close the ring. “Before this, we weren’t really sure that you could bend that sort of molecule into a ring at all,” Anderson says.
After freeing the 6 nm wide ring from its template, the researchers found that it could absorb light and funnel about 30% of the energy to the alkyne-linked portion within 350 fs, with the remainder following soon after.
Join the conversation
Contact the reporter
Submit a Letter to the Editor for publication
Engage with us on X