Yutao Sang obtained his B.Sc. and M.Sc. degrees in chemistry from Qingdao University, China. In 2016, he enrolled on a Ph.D. course at the Institute of Chemistry, Chinese Academy of Sciences (ICCAS), under the supervision of Prof. Minghua Liu, where he is currently in his third year. His ongoing research includes supramolecular chirality, chiroptical materials, and symmetry breaking of achiral molecules in gels and related systems. Pengfei Duan received his Ph.D. degree from the Institute of Chemistry, Chinese Academy of Sciences (CAS) in 2011 with Prof. Minghua Liu on chiral selfassembly in colloid and interface chemistry. He was a postdoctoral research fellow with Prof. Nobuo Kimizuka at Kyushu University, working on photon upconversion in self-assembled systems. In 2015, he became a professor at the National Center for Nanoscience and Technology (NCNST). His current research interests focus on photochemistry and photophysics in chiral supramolecular systems.

Transfer of both chirality and energy information plays an important role in biological systems. Here we show a chiral donor π-gelator and assembled it with an achiral π-acceptor to see how chirality and energy can be transferred in a composite donor–acceptor system. It is found that the individual chiral gelator can self-assemble into nanohelix. In the presence of the achiral acceptor, the self-assembly can also proceed and lead to the formation of the composite nanohelix. In the composite nanohelix, an energy transfer is realized. Interestingly, in the composite nanohelix, the achiral acceptor can both capture the supramolecular chirality and collect the circularly polarized energy from the chiral donor, showing both supramolecular chirality and energy transfer amplified circularly polarized luminescence (ETACPL).

Efficient triplet-triplet annihilation (TTA)-based photon upconversion (UC) is achieved in supramolecular organogel matrixes. Intense UC emission was observed from donor (sensitizer)-acceptor (emitter) pairs in organogels even under air-saturated condition, which solved a major problem: deactivation of excited triplet states and TTA-UC by molecular oxygen. These unique TTA-UC molecular systems were formed by spontaneous accumulation of donor and acceptor molecules in the gel nanofibers which are stabilized by developed hydrogen bond networks. These molecules preorganized in nanofibers showed efficient transfer and migration of triplet energy, as revealed by a series of spectroscopic, microscopic, and rheological characterizations. Surprisingly, the donor and acceptor molecules incorporated in nanofibers are significantly protected from the quenching action of dissolved molecular oxygen, indicating very low solubility of oxygen to nanofibers. In addition, efficient TTA-UC is achieved even under excitation power lower than the solar irradiance. These observations clearly unveil the adaptive feature of host gel nanofiber networks that allows efficient and cooperative inclusion of donor-acceptor molecules while maintaining their structural integrity. As evidence, thermally induced reversible assembly/disassembly of supramolecular gel networks lead to reversible modulation of the UC emission intensity. Moreover, the air-stable TTA-UC in supramolecular gel nanofibers was generally observed for a wide combination of donor-acceptor pairs which enabled near IR-to-yellow, red-to-cyan, green-to-blue, and blue-to-UV wavelength conversions. These findings provide a new perspective of air-stable TTA-UC molecular systems; spontaneous and adaptive accumulation of donor and acceptor molecules in oxygen-blocking, self-assembled nanomatrixes. The oxygen-barrier property of l-glutamate-derived organogel nanofibers has been unveiled for the first time, which could find many applications in stabilizing air-sensitive species in aerated systems.

Perovskite nanocrystals are attracting great interest due to their excellent photonic properties. Here, through a supramolecular self-assembly approach, the perovskite nanocrystals (NCs) with a novel circularly polarized luminescence (CPL) are successfully endowed. It is found that the achiral perovskite NCs can coassemble with chiral gelator in nonpolar solvents, in which the gelator molecules modify the surface of the perovskite NCs. Through such cogelation, the molecular chirality can transfer to the NCs resulting in CPL signals with a dissymmetric factor (g ) up to 10 . Furthermore, depending on the molecular chirality of the gelator, the CPL sense can be selected and the mirror-imaged CPL is obtained. Such gels can be further embedded into the polymer film to facilitate flexible CPL devices. It is envisaged that this approach will afford a new insight into the designing of the functional chiroptical materials.