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 sy stems uncovered with ultrabroadband 2D electronic spectroscopy
In light harvesting, solar energy is captured by arrays of coupled chromop hores and then funneled towards the site of energy conversion. A major road block in mapping the pathways of energy transfer had been that most previou s experiments measured only a narrow portion of the broad solar spectrum ca ptured by light-harvesting systems. I will present the development of ultra broadband 2D electronic spectroscopy, an ultrafast spectroscopic tool that enables mapping of energy flow across the visible and the near-infrared ran ge, and how this technique enabled the discovery of previously inaccessible photophysics in natural and synthetic light-harvesting systems. First, I w ill present the elucidation of pathways responsible for photoprotection of green plants against excess sunlight. In the major light-harvesting protein of green plants, LHCII, I directly resolved a sub-picosecond photoprotecti ve chlorophyll-to-carotenoid energy transfer process, which had only been t heoretically proposed. By introducing a systematically controllable near-na tive membrane platform that mimics the plant membrane, I also determined th e previously inaccessible impact of physiological parameters such as protei n crowding and protein-lipid interaction. I will then discuss another appli cation where a new type of light-matter interaction, known as polaritons, i s used as a means to manipulate the dynamics of energy flow in semiconducti ng carbon nanotubes. Formed by strong coupling between photons and molecule s, polaritons enable a plethora of new photophysics, such as long-range ene rgy transfer, the presence and mechanism of which, however, had not been el ucidated. A combination of ultrabroadband 2D measurements and quantum calcu lations revealed the spectroscopic signatures of the hypothesized long-rang e energy transfer as well as its underlying mechanism, which involves an in tricate interplay between light-matter coupling and molecular parameters. p>
Hosted by Professor Wilma Olson
~Coffee/tea will be serv ed prior to the lecture~
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:20240329T154354 DTSTART:20230209T154000 SEQUENCE:0 TRANSP:OPAQUE END:VEVENT END:VCALENDAR