Patent ID: 7718325

Claim:
A photochromic compound having a conjugated pathway, the photochromic compound having the formula (1), (2), or (3): wherein: each of R 1 -R 6 independently represents a group selected from the group consisting of hydrogen, alkyl, aryl, arylalkyl, silyl, nitro, cyano, halide atoms, amine, hydroxyl, alkoxy, aryloxy, alkylthio, arylthio, aldehyde, ketone, ester, amide, carboxylic acid, and sulfonic acid, wherein the alkyl, aryl, and arylalkyl groups can optionally be substituted with one or more groups selected from the group consisting of silyl groups, nitro groups, cyano groups, halide atoms, amine groups, hydroxy groups, alkoxy groups, aryloxy groups, alkylthio groups, arylthio groups, aldehyde groups, ketone groups, ester groups, amide groups, carboxylic acid groups, and sulfonic acid groups, X is a heteroatom selected from the group consisting of N, O, and S, and Y represents an alkene group of from 3 to about 15 carbon atoms and provides at least one conjugated double bond to a double bond of the parent molecule; where each of R 1 , R 2 , and R 3 are defined as above, and X in formulae (2) and (3) is an alkene group of from 3 to about 15 carbon atoms and provides at least one conjugated double bond to the double bond of the parent molecule.