Q1: Who helped you the most as you pursued your research career?
Prof. Duan: I really appreciate the great support from my doctoral and post-doctoral supervisors, Prof. Minghua Liu and Prof. Nobuo Kimizuka. I was guided to pursue an academic career in supramolecular chemistry and chirality by Prof. Liu, while Prof. Kimizuka exposed me to the challenges of photochemistry and physics. After establishing my independent research group, I endeavored to develop a new topic that integrated supramolecular chirality and photochemistry. One of the research topics in my group is chiral luminescence in supramolecular assemblies. This is the fusion, development, and continuation of the academic ideology from my two mentors. Their influence also motivates me to give assistant and guidance to young students for pursuing their research career.
Q2: What are some difficult challenges you have faced during your research career? How did you overcome them?
Prof. Duan: As a principle investigator, challenges exist everywhere. It is difficult for me to figure out the 「most difficult」 one. They were all very difficult, making my hair less and less. I think the common one that most new researchers will experience is determining new research topic. I initiated my research program by continuing work I started in my postdoctoral position. After a period of time, it becomes easy to find some new clues. Then concentrate on these new clues and explore them deeply and thoroughly.
Q3: Who is(are) scientist(s) you most respect or admire? Why?
Prof. Duan: I highly respect and admire those scientists who can donate their whole independent research career to one research theme. There are many respectable scientists. In the research area of photochromic dyes, that is the same topic with our recent work published on CCS Chemistry, Prof. Masahiro Irie is the first inventor of photochromic diarylethene and has been contributing to this field for more than 30 years. Until very recently, he continues to publish excellent work in this field.
Q4: What do you see as the biggest obstacles and most promising applications in your research area?
Prof. Duan: At present, one of the main research issues in my group is circularly polarized luminescence (CPL) of chiral materials. Actually, I am a newcomer in this field. The biggest obstacles in this area, in my opinion, is developing CPL materials with high circular polarization as well as luminescence quantum yield. The most promising application of these kinds of materials is the circularly polarized electroluminescence in organic light emitting diodes (OLED), which will enable 3D displays or improve the performance of OLEDs.
Q5: What advice do you have for younger students and researchers beginning their careers in chemistry, and in particular those interested in your field?
Prof. Duan: I would like to share this concept, 「The ideas you can think of, others have thought of yet. The ideas you cannot think of, others have thought of yet.」 Think deeply about your research direction and jump out of the box from time to time to see the position of your research.
Q6: Thank you for publishing your superb work in CCS Chemistry! Could you provide a brief summary of your article and research direction in a few sentences?
Prof. Duan: The topic of our paper in CCS Chemistry is on photon upconversion based on single photon absorption mechanism. This finding was serendipitous when we investigated the triplet exciton of luminescent diarylethene. Photon upconversion generally requires more than two low-energy photons to produce one high-energy photon. However, another typical anti-Stokes process of single-photon-absorption-based upconversion by excitation of thermally excited vibrational-rotational energy levels of ground state to the first level of excited state is less involved in organic systems due to the limitation of appropriate materials. In this work, we found one series of fluorescent diarylethenes, that exhibited SPA-UC phenomenon in the closed-ring state. Phonon-assisted or hot bands absorption should be in charge of the achievement of SPA-UC. Photon upconverison can be switched on/off by cyclization and cycloreversion reaction with UV and visible light. We envision these remarkable properties should be useful for super-resolution fluorescence imaging and bio-imaging.
Learn more: Jianlei Han , Jian Zhang*(張建), Tonghan Zhao, Minghua Liu & Pengfei Duan*(段鵬飛). Photoswitchable Photon Upconversion from Turn-on Mode Fluorescent Diarylethenes. CCS Chem. 2020, 2, 665–674.
Link: https://doi.org/10.31635/ccschem.020.202000227