Effect of Substituents in the 5' and 7' Positions on the Spectra of Merocyanines of 1,3,3-Trimethyl-6'-nitroindoline-2-spiro-2'--chromenes

Article abstract of DOI:10.1007/BF00503335

The corresponding photochromic 5',7'-disubstituted indolinospirochromenes were obtained by the reaction of 4,6-dialkoxy-5-nitrosalicylaldehydes, as well as 4,6-dimethyl-5-nitrosalicylaldehyde, with 1,3,3-trimethyl-2-methyleneindoline.Bulky electron-donor