Photonic and Reactive Molecular Science Laboratory

Staff & Contact

Educational Staff	Prof. Tsuyoshi Kawai Adjunct Prof. Keitaro Nakatani Associate Prof. Tsumoru Morimoto Adjunct Associate Prof. Louis Marine Assistant Prof. Mihoko Yamada
Contact	FAX: +81-743-72-6179
URL	https://mswebs.naist.jp/LABs/kawai/en/index.html

Education and Research Activities in the Laboratory

Research activity of this laboratory is focused on “Photonic and Reactive Molecular Science”, a new research field covering molecules, and coordination compounds with advanced photo-functionality and reactivity. We create new photo-reactive and light-emissive molecules as well as novel chemical synthetic procedure and catalysts. Students experience synthetic organic chemistry for developing new molecules and catalytic systems. Fundamental knowledge related to organic chemistry, physical chemistry and/or spectrochemistry is expected for the students who wish to join us. We welcome motivated students who have been educated in chemistry and chemistry-related fields in overseas universities as well as domestic universities. Our current research interest is dedicated to following items.

Research Themes

1. Photoresponsive Molecules and Photoreactions

Photochromic terarylene is most extensively studied in our team. Not only color changing materials, we explore and deliver new photoswitching materials and light sensing materials. For example, photo-control of supramolecular aggregates and their fluorescence properties are one of typical targets. We also explore new photo-induced catalysts which are based on photochromic terarylenes and newly developed naphthoquinone-based photo-labile molecular system. These photoreactive molecules are expected for future radio-sensing materials, medical stimulative reagents, and photo-resistive and photocuring materials.

2. Intelligent luminescent Molecules

Photoluminescent molecules are widely used and further intensively developed for future display devices, light-devices, sensors, inks and markings. We explore new molecular luminescent materials with advanced “intelligent” features, for lighting future of materials chemistry. Chiral luminescent molecules and coordination substances are extensively studied in our team which emit circularly polarized light for future marking inks and lighting devices. Some molecules with delayed luminescence feature and inverted triplet energy levels are recently developed for future efficient light sources.

3. Advanced catalysts and reaction systems for efficient organic synthesis

We create new synthetic reactions and catalysts especially based on transition metal complexes such as Rh(II). Some of them display unique catalytic reactivity toward trans-carbonylation reactions. We also aim to develop new fluoroalkane chemistry for future efficient usage of low-reactive fluoroalkane waste chemicals affording valuable chemicals.

Explanatory Pictures of Research Activities

Fig.1 We aim to develop new sensing systems; the hazardous radiations such as Ultra-Violet and X-ray oxidative triggers the color-changing cascade of new dyes for 1000 times.

Fig.2 New photolabile molecules for photorelease of functional compounds (a) and new catalytic transformation of sustainably available formaldehyde (b).

Fig.3 Highly sensitive photochromism of tetrathienyl corannulene with the curved aromatic skeleton.

Fig.4 We develop efficient fluorescent molecules which allows to use triplet excited state (T1) for light emission through the delayed fluorescence process for future efficient light emitting devices. Dimerized structure of donor-acceptor pair is efficient in our system.

Recent Research Papers and Achievements

Y. Tsuji, N. Kanno, C. Goto, S. Katao, Y. Okajima, P. Reine, P. Imbrasas, S. Reineke, K. Shizu, T. Nakashima, H. Kaji, T. Kawai, M. Louis,” A binaphthalimide motif as a chiral scaffold for thermally activated delayed fluorescence with circularly polarized luminescence activity”, J. Mater.Chem.,C,11, 5968-5978 (2023).
E. Hayashi, N. Akiyama, K. Kakiuchi, T. Kawai, T. Morimoto, “Cationic Rhodium (I)‐Catalyzed Asymmetric Cyclohydroformylation of 1, 6‐Enynes with Formaldehyde”, Chem.-An Asian J., 18, e202201241 (2023).
Mihoko Yamada, Tomoya Sawazaki, Mae Fujita, Fumio Asanoma, Yoshiko Nishikawa, Tsuyoshi Kawai, “Tetrathienyl corannulene compounds with highly sensitive photochromism”, Chem. Eur., J, 28, e202201286 (2022).
R. Asato, C. J. Martin, J. P. D. C. Calupitan, R. Mizutsu, T. Nakashima, G. Okada, N. Kawaguchi, T. Yanagida, T. Kawai, “Photosynergetic Amplification of Radiation Input: from Efficient UV Induced Cycloreversion to Sensitive X-ray Detection”, Chem. Sci., 11, 2504-2510 (2020)
R. Mizutsu, R. Asato, C. J. Martin, M. Yamada, Y. Nishikawa, S. Katao, M. Yamada, T. Nakashima, T. Kawai, “Photo-Lewis Acid Generator Based on Radical-Free 6-pai Photo-Cyclization Reaction”, J. Am. Chem. Soc., 141, 20043-20047 (2019)
S. Yonezawa, R. Sethy, G. Fukuhara, T. Kawai, T. Nakashima, “Pressure-dependent guest binding and release on a supramolecular polymer”, Chem. Commun., 55, 5793-5796 (2019)
M. Louis, R. Sethy, J. Kumar, S. Katao, R. Guillot, T. Nakashima, C. Allain, T. Kawai, R. Métivier, “Mechano-Responsive Circularly Polarized Luminescence of Organic Solid-State Chiral Emitters”, Chem. Sci., 10, 843-847 (2019)