Event
Chemical Society Seminar: Youhei Takeda-Triplet-Harvesting Organic Emitters Based on a Dibenzo[a,j]phenazine Core: From Novel Synthesis to Multifunctional Applications
Tuesday, November 11, 2025 13:00to14:30
Maass Chemistry Building
OM 10, 801 rue Sherbrooke Ouest, Montreal, QC, H3A 0B8, CA
Abstract:
The听design听of听high-performance,听multifunctional听organic emitters is听pivotal听for advancing听technologies in听optoelectronics, sensing,听and bio-imaging.听Heavy-metal-free organic听materials that听efficiently听harvest triplet excitons and converting them听into light听are emerging as听next-generation听candidates听for听high-efficiency听organic light-emitting diodes (OLEDs)听From听a materials-design听standpoint,听twisted or resonant听donor-acceptor听(D鈥揂)听飦�-conjugated听systems听are听promising听for听thermally听activated听delayed听fluorescence听(TADF),听as听they听spatially听separate听HOMO听and听LUMO听to reduce听singlet-triplet听energy听gaps,听thereby听accelerating听reverse听intersystem听crossing.听听
In 2014, we听achieved a听synthetic听breakthrough听via an听oxidative skeletal rearrangement of听binaphthalene听diamines (BINAMs), leading听to听the previously inaccessible听dibenzo[a,j]phenazines (DBPHZ)听scaffold.听Leveraging听the unique听structure听and听physicochemical properties听of DBPHZ, we听designed and synthesized听novel听DBPHZ-cored听emitters, including听twisted D鈥揂鈥揇 triads and D鈥揂鈥揇鈥揂 macrocycles. These听emitters听exhibit听advanced photophysical听functionalities鈥攅fficient TADF, multi-color-mechanochromic听luminescence, and room-temperature phosphorescence (RTP).听
This听presentation will听cover听key publications including:听听
1)听Chem. Commun.听2014,听50, 10291;听2)听Angew. Chem., Int. Ed.听2016,听55, 5739;听3)听Chem. Sci.听2017,听8, 2677;听4)听Chem. Commun.听2018,听54, 6847;听5)听Commun. Chem.听2020,听3, 118; 6)听J. Am. Chem. Soc.听2020,听142, 1482; 7)听ACS Appl. Mater. Interfaces听2021,听13, 2899; 8)听Angew. Chem., Int. Ed.听2024,听63, e202405158; 9)听Acc. Chem. Res.听2024,听57, 2219; 10)听ChemRxiv听doi: 10.26434/chemrxiv-2025-sfp9s.听
础肠办苍辞飞濒别诲驳别尘别苍迟蝉听听
Parts of this听research听were听supported by听the JST ASPIRE program (Adopting Sustainable Partnerships for Innovative Research Ecosystem;听Grant听No.听JPMJAP2424), which aims to foster international collaboration and advance Japan鈥檚 research ecosystem.听听
听
Bio:
Youhei听Takeda听is an Associate Professor at Osaka University.听Youhei听earned听his听B.Eng.听from听Waseda听University听in 2005, followed by his听Ph.D. from Kyoto University in 2010 under the听guidance of听Professor听Tamejiro听Hiyama. He then conducted听postdoctoral听research听at Massachusetts Institute of Technology听(MIT) with Professor听Timothy M. Swager, during which, he was appointed as JSPS research fellow (DC2 and PD).听In 2011,听he听joined Osaka University as an听Assistant Professor听and听was promoted to Associate Professor in 2015. His achievements have been widely recognized,听receiving several prestigious awards, including the听Incentive Award in Synthetic Organic Chemistry, Japan (2019), The Young Scientists鈥� Prize from the MEXT (2020), The听Nozoe听Memorial Award for Young Organic Chemists (2020), Thieme Chemistry Journals Award (2021), and Asian Core Program Lectureship Award (2023). His research听focuses on听the innovative听design听and听synthesis听of听heteroatom-embedded exotic 蟺-conjugated organic molecules, with applications spanning various interdisciplinary fields.听