Dear Colleagues,
The Global XAS Journal club is an ongoing virtual seminar series. The
seminar for this week in the Americas/Europe time window is below -- you
can forward this to interested persons in the XAS community but *please do
not make any public posting *(we've had problems with zoom-bombing).
Please email me seidler@uw.edu to be added to the direct mailing
list, where you would get this information for both the Americas/Europe and
also Asia-Oceania/Europe timed seminars. About 70 prior lectures are
available at the youtube channel
https://www.youtube.com/channel/UCwtkyiTV4BltKTQ7tS0CltQ/videos
Looking to August and the autumn term I am particularly interested in
finding:
(1) XAS speakers who are early career scientists, such as postdocs,
assistant professors, or new staff scientists at facilities and national
labs, and
(2) beamline scientists to speak about capabilities and science
outcomes/goals at their beamlines.
Please send suggestions!
Cheers,
Jerry Seidler (seidler@uw.edu)
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*X-ray Spectroscopy of Light-induced Chemical Reactions -- A New Universal
Probe of Photoexcited Molecular Dynamics *
Prof. Aditi Bhattacherjee (University of Iowa)
Thursday July 15: 9 am Seattle (PDT), 12 noon NY, 5 pm London, 6 pm
Berlin, 7 pm Moscow
link: https://washington.zoom.us/j/96246359168
password: EXAFS
*Abstract*: Photochemical reactions of small organic molecules are
prevalent in the atmosphere, in biological machineries and photocatalytic
materials. Recent laboratory breakthroughs have enabled access to ultrafast
X-ray spectroscopy at the carbon K-edge (1s absorption edge of carbon, at
284 electron volts). This has opened new avenues to explore ultrafast
reaction mechanisms in a host of photochemical reactions in small molecules
with high temporal resolution.[1] In this talk, I will discuss experiments
that show how the excitation of 1s-core electrons of the constituent carbon
atoms in organic molecules is a key spectroscopic probe of photoinduced
molecular dynamics.
First, I will present the mechanistic details that emerge in the ultrafast
ring-opening reactions of hydrocarbon as well as heteronuclear organic
molecules from the direct orbital sensitivity of time-resolved X-ray
absorption spectroscopy at the near edge.[2,3] Second, I will also show
that in favorable cases, ultrafast intersystem crossing in molecules can be
identified even though X-ray absorption spectroscopy is not directly
sensitive to spin states.[4] Our work reveals that future chemical
applications of this method at multiple absorption edges may provide new
universal spectroscopic probes of photoinduced molecular dynamics.
*Suggested reading*:
[1] Bhattacherjee and Leone AccChemRes 21, 3203, 2018.
https://pubs.acs.org/doi/10.1021/acs.accounts.8b00462
[2] Attar, Bhattacherjee, Das, Schnorr, Closser, Prendergast, and Leone
Science 356, 54, 2017. https://science.sciencemag.org/content/356/6333/54
[3] Bhattacherjee, Schnorr, Oesterling, Yang, Xue, Vivie-Riedle and Leone
JAmChemSoc 140, 39, 12538, 2018.
https://pubs.acs.org/doi/10.1021/jacs.8b07155
[4] Bhattacherjee, Das, Schnorr, Attar and Leone JAmChemSoc 139, 46, 2017.
https://pubs.acs.org/doi/abs/10.1021/jacs.7b07532
--
*Gerald Seidler*
*Professor, Physics Department*
*University of Washington*
*http://faculty.washington.edu/seidler/index.html
http://faculty.washington.edu/seidler/index.html*
*seidler@uw.edu