S. Aiken, Daniel A. Clayton, C. Gabbutt
Apr 1, 2013
Citations
0
Influential Citations
5
Citations
Journal
Dyes and Pigments
Abstract
Abstract A series of mono-, bis- and tris-4-(naphthopyran-3-yl)phenyl substituted methanols were efficiently synthesised using a 4-(naphthopyran-3-yl)phenyllithium intermediate. The resulting substituted methanols displayed good photochromism leading to the reversible generation of red–orange photomerocyanines. Acidic dehydration of the methanols gave intensely coloured cations which, upon subsequent UV irradiation, reversibly generated cationic photomerocyanines with long wavelength absorption maxima at ca. 640 nm.