S. Nespurek et al., PHOTOCHROMISM OF 4H-THIOPYRANS AND 1,4-DIHYDROPYRIDINES, Molecular crystals and liquid crystals science and technology. Section A, Molecular crystals and liquid crystals, 246, 1994, pp. 139-142
There is current interest in reversible photochemical recording system
s. In addition to known photochromic reactions [1,2]., such as cis-tra
ns isomerism, homolytic or heterolytic bond cleavage and tautomeric sh
ift of hydrogen, new types of photoreactions are generally possible.