Kamogawa, Hiroyoshi et al. published their research in Journal of Polymer Science, Polymer Chemistry Edition in 1984 |CAS: 52243-87-5

The Article related to photochromism viologen aprotic polymer matrix, Radiation Chemistry, Photochemistry, and Photographic and Other Reprographic Processes: Radiation Chemistry and Photochemistry and other aspects.Electric Literature of 52243-87-5

On February 29, 1984, Kamogawa, Hiroyoshi; Masui, Toshiaki; Amemiya, Suguru published an article.Electric Literature of 52243-87-5 The title of the article was Organic solid photochromism by photoreduction mechanism: viologen embedded in solid polar aprotic polymer matrix. And the article contained the following:

Reversible photocolor development of viologens embedded in poly(N-vinyl-2-pyrrolidone) (I) films, a typical polar aprotic solid matrix, was affected by the kinds of viologen cation as well as the paired anion. The color development in the corresponding low-mol.-weight solvents is connected closely to the solubility of viologens in these solvents; viologens are highly sensitive in the polar aprotic solvents in which they have poor solubilities, such as N-methyl-2-pyrrolidone and hexamethylphosphoric triamide. These facts confirm the color-development mechanism consisting of electron transfer to the photoexcited viologen cation from the paired anion in polar aprotic solid matrixes, such as I. The experimental process involved the reaction of 1,1′-Dipropyl-[4,4′-bipyridine]-1,1′-diium bromide(cas: 52243-87-5).Electric Literature of 52243-87-5

The Article related to photochromism viologen aprotic polymer matrix, Radiation Chemistry, Photochemistry, and Photographic and Other Reprographic Processes: Radiation Chemistry and Photochemistry and other aspects.Electric Literature of 52243-87-5

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem