BEGIN:VCALENDAR VERSION:2.0 PRODID:-//jEvents 2.0 for Joomla//EN CALSCALE:GREGORIAN METHOD:PUBLISH BEGIN:VEVENT UID:888baf3916adfa89fc780e197e3b0a54 CATEGORIES:Seminar CREATED:20230127T134003 SUMMARY:Dr. Minjung Son, University of Wisconsin-Madison LOCATION:CCB-1209 DESCRIPTION:Pathways of excitation energy flow in light-harvesting systems uncovered wi th ultrabroadband 2D electronic spectroscopy\nIn light harvesting, solar en ergy is captured by arrays of coupled chromophores and then funneled toward s the site of energy conversion. A major roadblock in mapping the pathways of energy transfer had been that most previous experiments measured only a narrow portion of the broad solar spectrum captured by light-harvesting sys tems. I will present the development of ultrabroadband 2D electronic spectr oscopy, an ultrafast spectroscopic tool that enables mapping of energy flow across the visible and the near-infrared range, and how this technique ena bled the discovery of previously inaccessible photophysics in natural and s ynthetic light-harvesting systems. First, I will present the elucidation of pathways responsible for photoprotection of green plants against excess su nlight. In the major light-harvesting protein of green plants, LHCII, I dir ectly resolved a sub-picosecond photoprotective chlorophyll-to-carotenoid e nergy transfer process, which had only been theoretically proposed. By intr oducing a systematically controllable near-native membrane platform that mi mics the plant membrane, I also determined the previously inaccessible impa ct of physiological parameters such as protein crowding and protein-lipid i nteraction. I will then discuss another application where a new type of lig ht-matter interaction, known as polaritons, is used as a means to manipulat e the dynamics of energy flow in semiconducting carbon nanotubes. Formed by strong coupling between photons and molecules, polaritons enable a plethor a of new photophysics, such as long-range energy transfer, the presence and mechanism of which, however, had not been elucidated. A combination of ult rabroadband 2D measurements and quantum calculations revealed the spectrosc opic signatures of the hypothesized long-range energy transfer as well as i ts underlying mechanism, which involves an intricate interplay between ligh t-matter coupling and molecular parameters.\nHosted by Professor Wilma Olso n\n~Coffee/tea will be served prior to the lecture~\n X-ALT-DESC;FMTTYPE=text/html:
Pathways of excitation energy flow in light-harvesting systems uncovered with ultrabroadband 2D electr onic spectroscopy
In light harvesting, solar energy is captured by arrays of coupled chromophores and then funneled towards the site of energy conversion. A major roadblock in mapping the pathways of energy transfer h ad been that most previous experiments measured only a narrow portion of th e broad solar spectrum captured by light-harvesting systems. I will present the development of ultrabroadband 2D electronic spectroscopy, an ultrafast spectroscopic tool that enables mapping of energy flow across the visible and the near-infrared range, and how this technique enabled the discovery o f previously inaccessible photophysics in natural and synthetic light-harve sting systems. First, I will present the elucidation of pathways responsibl e for photoprotection of green plants against excess sunlight. In the major light-harvesting protein of green plants, LHCII, I directly resolved a sub -picosecond photoprotective chlorophyll-to-carotenoid energy transfer proce ss, which had only been theoretically proposed. By introducing a systematic ally controllable near-native membrane platform that mimics the plant membr ane, I also determined the previously inaccessible impact of physiological parameters such as protein crowding and protein-lipid interaction. I will t hen discuss another application where a new type of light-matter interactio n, known as polaritons, is used as a means to manipulate the dynamics of en ergy flow in semiconducting carbon nanotubes. Formed by strong coupling bet ween photons and molecules, polaritons enable a plethora of new photophysic s, such as long-range energy transfer, the presence and mechanism of which, however, had not been elucidated. A combination of ultrabroadband 2D measu rements and quantum calculations revealed the spectroscopic signatures of t he hypothesized long-range energy transfer as well as its underlying mechan ism, which involves an intricate interplay between light-matter coupling an d molecular parameters.
Hosted by Professor Wilma Olson
~Coffee/tea will be served prior to the lecture~
DTSTAMP:20240329T154558 DTSTART:20230209T154000 SEQUENCE:0 TRANSP:OPAQUE END:VEVENT END:VCALENDAR