Two Stage Colour Modulation of Triarylmethine Dyes Derived from a Photochromic Naphthopyran
作者:Christopher D. Gabbutt、B. Mark Heron、Suresh B. Kolla、Matthew Mcgivern
DOI:10.1002/ejoc.200800178
日期:2008.4
The synthesis of the unsymmetrical triarylmethine dyes 4derived from a lithiated naphthopyran and diaryl ketones is reported. In toluene solution 4 display a typical reversible photochromic response becoming coloured upon irradiation with UV light and fading upon cessation of irradiation. At low pH an intensely coloured dye cation is generated and UV irradiation of this solution results in a further