119th CEMS Colloquium


Prof. Nobuo Kimizuka (Kyushu University)


17:30 - 18:30, January 31, 2024 (Wednesday)


Okochi-Hall, RIKEN


Photon energy conversion by maximizing the potential of molecular self-assembly


Developing advanced technologies to harvest and convert solar energy effectively is one of the most critical issues. In recent years, we have developed molecular systems that show photon-up conversion based on self-assembly. Triplet-triplet annihilation-based photon upconversion (TTA-UC) is a promising methodology that can be applied to many sunlight-based energy conversion systems. Fundamental studies of TTA-UC have focused on the diffusion of excited triplet molecules in organic media, which limits their applications. Inspired by biological photosynthetic systems, we integrated the concepts of self-assembly and energy migration to develop efficient photon-upconverting molecular systems.1-12 Interestingly, some of the molecular self-assemblies dispersed in solution or organogels revealed oxygen barrier properties, which allowed TTA-UC even under aerated conditions.3,5,6-8 In this talk, we will discuss our recent development on the TTA-UC molecular systems with controlled energy landscapes, the design of NIR-to-Visible,9 and visible-to-UV upconversion materials in films.13-14 Also, the application of molecular self-assembly and phase transition to improve the performance of molecular solar thermal fuels (STFs) will be addressed,14-16 with the recent integration of triplet photochemistry and STFs.17

1) P. Duan et al, J. Am. Chem. Soc. 2013, 135, 19056.
2) S. Hisamitsu, et al, Angew. Chem. Int. Ed. 2015, 54, 11550.
3) P. Duan et al, J. Am. Chem. Soc. 2015, 137, 1887.
4) S. Hisamitsu et al, Phys.Chem.Chem.Phys. 2018, 20, 3240.
5) S. Hisamitsu et al, ChemistryOpen, 2020, 9, 14.
5) Bharmoria, P. et al, J. Am. Chem. Soc. 2018, 140, 10848.
6) T. Ogawa et al, Sci. Rep. 2015, 5, 10882.
7) N. Kimizuka, et al, Langmuir, 2016, 32, 12304 (Invited Feature Article).
8) N. Yanai, N. Kimizuka, Chem. Commun. 2016, 52, 5354.
9) S. Amemori et al, J. Am. Chem. Soc. 2016, 138, 8702.
10) Y. Sasaki et al, Angew. Chem. Int. Ed. 2019, 58, 17827.
11) T. Ogawa et al, J. Am. Chem. Soc. 2018, 140, 8788.
12) T. Kashino et al, ACS Appl. Mater. Interfaces 2022, 14, 22771.
13) N. Harada, et al, Angew. Chem. Int. Ed. 2021, 60, 142.
14) N. Harada et al, J. Mater. Chem. C 2023, 11, 8002.
14) K. Ishiba, et al., Angew. Chem. Int. Ed. 2016, 54, 153.
15) Y. Nagai et al, Angew. Chem. Int. Ed. 2021, 60, 6333.
16) M-a. Morikawa et al, RSC Advances 2023, 13, 24031.
17) M-a. Morikawa et al, Chem. Lett. 2023, 52, 727.