BEGIN:VCALENDAR VERSION:2.0 CALSCALE:GREGORIAN PRODID:iCalendar-Ruby BEGIN:VEVENT 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 END:VEVENT END:VCALENDAR
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