BEGIN:VCALENDAR VERSION:2.0 PRODID:IEEE vTools.Events//EN CALSCALE:GREGORIAN BEGIN:VTIMEZONE TZID:America/Denver BEGIN:DAYLIGHT DTSTART:20260308T030000 TZOFFSETFROM:-0700 TZOFFSETTO:-0600 RRULE:FREQ=YEARLY;BYDAY=2SU;BYMONTH=3 TZNAME:MDT END:DAYLIGHT BEGIN:STANDARD DTSTART:20261101T010000 TZOFFSETFROM:-0600 TZOFFSETTO:-0700 RRULE:FREQ=YEARLY;BYDAY=1SU;BYMONTH=11 TZNAME:MST END:STANDARD END:VTIMEZONE BEGIN:VEVENT DTSTAMP:20260316T225611Z UID:560FAF3B-6176-4F01-8C14-F46CFE773FBC DTSTART;TZID=America/Denver:20260327T110000 DTEND;TZID=America/Denver:20260327T120000 DESCRIPTION:Organic semiconductors\, comprised of Ļ€-conjugated aromatic sy stems\, have attracted considerable research interests owing to the earth abundance of their constituent elements\, including carbon\, hydrogen\, ni trogen\, oxygen\, and so on. In contrast to conjugated polymeric semicondu ctors\, small molecule organic semiconductors are particularly appealing d ue to simpler synthetic routes\, facile purification\, well-defined molecu lar structures\, improved processability\, and high reproducibility. Organ ic semiconductor possesses a small Frenkel exciton radius (~5 ƅ) and a hi gh exciton binding energy (0.3-1.0 eV)\, which limit the electron-hole (e āˆ’-h+) pairs separation within the same molecule. However\, the dissociat ion of eāˆ’-h+ pairs into free charge carriers can be facilitated through the incorporation of the donor-acceptor (D-A) architecture. In donor-accep tor systems\, intramolecular charge transfer (ICT) occurs through electron donation from the electron-rich donor unit to the electron-deficient acce ptor unit. Moreover\, the energies of the frontier molecular orbitals (HOM O and LUMO) in donor-acceptor-donor (D-A-D) systems can be tuned by varyin g the donor units\, thereby modulating their optical and electrochemical p roperties. Herein\, we employed a palladium-catalyzed cross-coupling react ion\, namely Suzuki-Miyaura coupling\, to synthesize different small molec ules having D-A-D structure with a common benzoselenadiazole acceptor unit . We tested these D-A-D systems to generate solar hydrogen by methanol pho toreforming. The D-A-D systems exhibited high-rate solar hydrogen evolutio n due to improved charge separation\, favorable redox potentials\, and red uced Gibbs free energy for methanol photoreforming compared to water split ting.\n\nCo-sponsored by: Resilience and Clean Energy Systems (RCES)\n\nSp eaker(s): Md Masud Rana\n\nVirtual: https://events.vtools.ieee.org/m/54917 4 LOCATION:Virtual: https://events.vtools.ieee.org/m/549174 ORGANIZER:bli4@ualberta.ca SEQUENCE:21 SUMMARY:High-rate Solar Hydrogen Evolution Using Small Molecule Donor/Accep tor Organic Semiconductors URL;VALUE=URI:https://events.vtools.ieee.org/m/549174 X-ALT-DESC:Description: <br /><p><span style="font-size: 12.0pt\; line-heig ht: 107%\; font-family: 'Times New Roman'\,serif\; mso-fareast-font-family : Aptos\; mso-fareast-theme-font: minor-latin\; mso-ansi-language: EN-CA\; mso-fareast-language: EN-US\; mso-bidi-language: AR-SA\;">Organic semicon ductors\, comprised of &pi\;-conjugated aromatic systems\, have attracted considerable research interests owing to the earth abundance of their cons tituent elements\, including carbon\, hydrogen\, nitrogen\, oxygen\, and s o on. In contrast to conjugated polymeric semiconductors\, small molecule organic semiconductors are particularly appealing due to simpler synthetic routes\, facile purification\, well-defined molecular structures\, improv ed processability\, and high reproducibility. Organic semiconductor posses ses a small Frenkel exciton radius (~5 &Aring\;) and a high exciton bindin g energy (0.3-1.0 eV)\, which limit the electron-hole (e<sup>&minus\;</sup >-h<sup>+</sup>) pairs separation within the same molecule. However\, the dissociation of e<sup>&minus\;</sup>-h<sup>+</sup> pairs into free charge carriers can be facilitated through the incorporation of the donor-accepto r (D-A) architecture. In donor-acceptor systems\, intramolecular charge tr ansfer (ICT) occurs through electron donation from the electron-rich donor unit to the electron-deficient acceptor unit. Moreover\, the energies of the frontier molecular orbitals (HOMO and LUMO) in donor-acceptor-donor (D -A-D) systems can be tuned by varying the donor units\, thereby modulating their optical and electrochemical properties. Herein\, we employed a pall adium-catalyzed cross-coupling reaction\, namely Suzuki-Miyaura coupling\, to synthesize different small molecules having D-A-D structure with a com mon benzoselenadiazole acceptor unit. We tested these D-A-D systems to gen erate solar hydrogen by methanol photoreforming. The D-A-D systems exhibit ed high-rate solar hydrogen evolution due to improved charge separation\, favorable redox potentials\, and reduced Gibbs free energy for methanol ph otoreforming compared to water splitting.</span></p> END:VEVENT END:VCALENDAR