193. Photoformation of (Z)-Isomers in Diarylazomethines. Part IV. Direct and Sensitized Photoisomerization of Pyridyl Analogues of Benzylidene-aniline and Absorption Spectra of their (Z)-Isomers

Article abstract of DOI:10.1002/hlca.19830660707

UV irradiation of solutions of the (E)-isomers of five (out of the possible six) monopyridyl analogues at reduced temperatures results in extensive (80-90percent) conversion into the corresponding (Z)-isomers.The process is reversible both thermally and photochemically.The (Z)-isomers are stable at temperatures below -80 deg, and their absorption spectra were estimated.Biacetyl-photosensitized (E)->(Z) isomerization was observed, with (Z)-contents of ca. 70percent at the photostationary state.