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CATEGORIES:Lectures & Presentations
DESCRIPTION:NQPI Seminar | Visible Light Coordination of a Rh(III)-BODIPY C
omplex to Guanine\, Oct. 20\n\nThe Nanoscale and Quantum Phenomena Institut
e (NQPI) 's Seminar Forum series features Eli Skelton discussing "Visible L
ight Coodination of a Rh(III)-BODIPY Complex to Guanine" Oct. 20 at 4:10 p.
m. in Walter 245.\n\n \n\nSkelton is a graduate student in Chemistry & Bioc
hemistry at Ohio University.\n\n \n\nAbstract: Cancers treated by chemother
apy use reagents such as cisplatin. Cisplatin is a Pt(II) metal complex tha
t terminates cancer cells after undergoing thermal hydrolysis in a solution
that activates covalent binding to DNA. Cisplatin is nonselective in diffe
rentiating healthy cells from cancer cells and targets them indiscriminatel
y causing unwanted side effects such as ototoxicity and nephrotoxicity. Pho
todynamic therapy uses photochemical properties of chemical reagents to sel
ectively target cancer cells using visible light. Most photodynamic therape
utics are oxygen-dependent and cannot effectively treat tumors in hypoxic e
nvironments. This research aims to take on this challenge by using Rh(III)
polypyridyl complexes’ photochemical properties. When irradiated with UV li
ght\, cis-[RhIII(NN)2Cl2]+ complexes (where NN is a bidentate polypyridyl l
igand) can photodissociate chloride and then covalently bind to DNA\, but U
V light damages tissue. To make these Rh(III)complexes more visible light a
ctive\, a BODIPY fluorophore is coupled to the Rh(III) metal center. BODIPY
is an emissive fluorophore that absorbs visible light strongly and can und
ergo excited-state electron transfer. This complex is designed so that the
highest molecular orbital (HOMO) is localized around the BODIPY and the low
est molecular orbital (LUMO) is localized around the Rh(III) metal center.
The coupling of BODIPY to Rh(III) greatly expanded the electronic absorbanc
e into the visible region with an absorption maximum at 529 nm which as bee
n assigned as the BODIPY π→π*. Irradiation using 532 nm light (green light
)\, it is observed that the BODIPY π→π* transition at 529 nm decreases. Usi
ng spectroelectrochemistry\, a similar decrease is observed upon BODIPY oxi
dation\, which supports photo-oxidation of BODIPY upon irradiation with vis
ible light. In addition\, photobinding of the Rh(III)-BODIPY complex was ob
served by mass spectrometry after chloride dissociation with visible light.
Calculated thermochemistry values of the Rh complex reaction in methanol\,
acetonitrile\, water\, and guanine were determined using DFT calculations.
All enthalpic reactions and Gibbs free energies were identified as endothe
rmic and nonspontaneous\, respectively. This observation supports the chlor
ide dissociation using 532 nm light. This Rh(III)-BODIPY complex expands th
e class of visible light-activated Rh(III) photo-cisplatin analogs that may
have potential photodynamic therapeutic activity for the treatment of canc
ers in hypoxic conditions.
DTEND:20221020T211000Z
DTSTAMP:20241124T200512Z
DTSTART:20221020T201000Z
GEO:39.322732;-82.10287
LOCATION:Walter Hall\, 245
SEQUENCE:0
SUMMARY:NQPI Seminar | Visible Light Coordination of a Rh(III)-BODIPY Compl
ex to Guanine\, Oct. 20
UID:tag:localist.com\,2008:EventInstance_41305077762815
URL:https://calendar.ohio.edu/event/nqpi_seminar_oct_20_2
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