Mj. Preigh et al., BIVALENT-METAL ION-DEPENDENT PHOTOCHROMISM AND PHOTOFLUOROCHROMISM FROM A SPIROQUINOXAZINE, Journal of the Chemical Society, Chemical Communications, (20), 1995, pp. 2091-2092
Illumination of solutions of spiroquinoxazine 1 yields both a coloured
species and a fluorescent species, both of which are reverse photochr
omic and both of which are trapped by bivalent metal ion complexation.