Photochemically Stable Novel Yellow Developing Photochromic Compounds Having a Thiazole Group

ABSTRACT

Diarylethene derivatives having a thiazole ring as the aryl group 1a , 2a , and 3a have been synthesized in an attempt to obtain photochromic compounds which change the color from colorless to yellow, and have low photocycloreversion quantum yields and high absorption coefficients of the colored isomers. Compounds 1 and 3 exhibited reversible photochromic reactions in hexane solution. The closed-ring isomers 1b and 3b showed orange and yellow colors, respectively. The ϵ value of 3b at the absorption maximum is 18400 M⁻¹cm⁻¹, which is much larger than those of 1b (ϵ = 10000 M⁻¹cm⁻¹) and 2b (ϵ = 11400 M⁻¹cm⁻¹). The photocyclization/cycloreversion quantum yields of 3 were determined to be 0.19 and 0.0014, respectively. The yellow color was sufficiently photochemically stable under room light.

Keywords:

• absorption coefficient
• diarylethene
• photochromism
• photocycloreversion quantum yield
• yellow photochromic dye

Acknowledgments

This work was partly supported by “Nanotechnology Support Project” of the Ministry of Education, Culture, Sports, Science, and Technology (MEXT), Japan and a Grant-in-Aid for Scientific Research(S) (No. 15105006) from the Ministry of Education, Culture, Sports, Science, and Technology (MEXT), Japan.