Patent ID: 8801976

Claim:
A stable photochromic dye, comprising: at least two photo-reactive groups including: a first photo-reactive group configured to undergo a first reversible photochromic reaction in response to radiation having a first wavelength; a second photo-reactive group configured to undergo a second reversible photochromic reaction in response to radiation having a second wavelength; wherein, the at least two photo-reactive groups are coupled to one another by a non-conjugated linkage selected from the group consisting of C 1-12 alkylene, C 1-12 heteroalkylene, C 1-12 alkoxy, C 1-6 alkylenoxy, C 1-6 alkylenedioxy, C 1-6 phenyleneoxy, and C 1-12 phenylenedioxy; wherein, the first photo-reactive group and second photo-reactive group are independently at least one structure selected from the group consisting of Formula I and II: wherein, R 1 to R 15 independently represent hydrogen, a halogen, a substituted or unsubstituted C 1-12 alkyl, a substituted or unsubstituted C 1-12 alkoxy, a substituted or unsubstituted C 1-12 alkenyl, a substituted or unsubstituted C 1-12 conjugated alkyl, a substituted or unsubstituted aryl group, or a substituted or unsubstituted heteroaryl group or the substituents together form an alkylene or alkenylene chain completing an aryl group.