Patent ID: 8536205

Claim:
A precursor for preparation of a photoactive hexatriene compound, wherein the precursor is represented by formula II: wherein, X is S, N or O; R 1 is selected from the group consisting of H, a halogen, methyl and aryl; R 2 is selected from the group consisting of methyl and aryl; R 3 is selected from the group consisting of H and methyl; R 4 is selected from the group consisting of H, methyl, aryl, an electron-donating group, an electron-accepting group, n-C 3 H 7 , C 5 H 4 , 4-C 6 H 4 OCH 3 , 3,4,5-C 6 H 2 (OCH 3 ) 3 , 4-C 6 H 4 -NO 2 and 4-pyridyl, and a constituent of an optionally substituted heterocycle; R 5 is selected from the group consisting of methyl, aryl, an electron-donating group and an electron-accepting group; R 6 is selected from the group consisting of methyl, aryl, an electron-donating group, an electron-accepting group, and a constituent of an optionally substituted heterocycle; and R 7 and R 8 are each carbon-containing groups, or when taken together form a 5-membered ring substituted by H or a halogen, or together form an optionally substituted 6-membered ring; wherein the electron-donating group is selected from the group consisting of phenols, phenol ethers, anilines, thiophenes, and sulfides, and wherein the electron-accepting group is selected from the group consisting of carbonyl-based functional groups, nitriles, nitrobenzene, and pyridine.