Professor Tsuyoshi Kawai from the Photonic and Reactive Molecular Science Laboratory has received the 2025 APA–Masuhara Lectureship Award from the Asian and Oceanian Photochemistry Association (APA).
Summary
Professor Tsuyoshi Kawai received the 2025 APA–Masuhara Lectureship Award at the Asian and Oceanian Photochemistry Conference (APC2025) held in Kochi, Kerala, India, on October 21, 2025.
The Asian and Oceanian Photochemistry Association (APA) is an international organization promoting photochemistry research across the Asia–Pacific region. It was established in 2001 through the collaboration of Japan and nine other national and regional photochemistry societies, as a sister organization to the European Photochemistry Association (EPA) and the Inter-American Photochemistry Society (I-APS).
The Masuhara Lectureship Award, founded in 2014 in honor of Professor Hiroshi Masuhara, the inaugural president of APA and Visiting Professor at NAIST, recognizes distinguished scientists worldwide for their outstanding invited lectures in the field of photochemistry.
Presentation title
Photochromic Molecules Based on Peri-Photocyclization Reactions
Research detail
The peri-photocyclization reaction is a photochemical process in which six π-electrons undergo a concerted ring-closure upon light irradiation. This class of reactions has long been investigated in systems such as diarylethenes, which are central to photochromic molecular design.
Professor Kawai and his collaborators have pioneered the structural expansion of diarylethene frameworks, leading to unique photoresponsive functions such as Photon-quantitative reaction, photoacid generation, chain-type molecular sensing, and modulation of fluorescence and phosphorescence. They have also established fundamental molecular design principles for these systems.
Traditionally, peri-photocyclization reactions were limited to 6π-electron systems. In 2025, Professor Kawai’s team discovered for the first time that a 10π-electron photocyclization can proceed via a similar orbital-symmetry–controlled mechanism. This finding represents a significant advance in photochemistry, realizing a reaction pathway that had been theoretically predicted based on the Frontier Molecular Orbital Theory proposed by Professor Kenichi Fukui, the first Asian Nobel Laureate in Chemistry (1981).
Comment
It is a profound honor to receive this international lectureship award named after Professor Hiroshi Masuhara, a pioneering figure in the field of photochemistry.
I would like to take this opportunity to express my deep respect for Professor Masuhara’s remarkable contributions to the advancement of photochemical science, and to extend my sincere gratitude for the generous support I have received from Professor Masuhara.
I am also deeply thankful to all members of NAIST, particularly those in my research group—faculty, students, and alumni—who have contributed to this work, as well as to the member of Materials Research Platform Center and the Medilux Research Center for their mindful support.
My heartfelt appreciation goes to my colleagues in the Division of Materials Science and to all domestic and international collaborators who have contributed to the success of this research.