[19p-P7-1~81] 2 Ionizing Radiation（Poster）

[19p-P7-72] Domino-chromic reaction for X-ray sensitive molecular material

〇Ryosuke Asato¹, Jan Patrick Calupitan^2,3, Go Okada¹, Takuya Nakashima¹, Noriaki Kawaguchi¹, Takayuki Yanagida¹, Tsuyoshi Kawai¹ (1.NAIST, 2.CEMES-CNRS, 3.Touluse-2 Univ.)

Keywords:X-ray ditection, Organic material, Photochromic molecules

Photochromic terarylenes undergo electrocyclization reaction by UV irradiation to form colored closed-ring isomers, which can be returned to colorless open-ring isomers via visible irradiation. Some terarylenes were reported to show very efficient cycloreversion reaction upon oxidation. In this study, we investigated the structure-reactivity relationship of photochromic diarylthiazoles on the oxidative cycloreversion reaction and found the ultra-efficient ring opening reaction via the domino reaction of charge transfer with over 20,000% in amplification efficiency. By introducing aromatic groups on the reactive carbon atoms at the ends of a photoreactive 6π system in a dithiazolylthiazole, turnover rates of the net bleaching reaction increased greatly.
Even more surprisingly, we successfully performed this oxidative cycloreversion reaction by X-ray irradiation. Upon irradiation with dose of 1mGy to the chloroform solution of closed form, decrease in the visible range absorption band was observed. This absorbed dose is 1000 times sensitivity limits of conventional organic detection material. At this conference, I will present conditions and mechanisms to cause high efficiency X-ray induced reaction