Patent ID: 8304537

Claim:
A method of switching reversibly optical properties of a compound or a material containing the compound by a change in electric current or potential, temperature, or pH; wherein said compound is of Formula I: wherein (i) R 1 , R 2 , R 3 and R 4 are independently selected from the group consisting of hydrogen, hydroxyl, C5-C6 cycloalkyls, substituted C5-C6 cycloalkyls, C5-C6 heterocycles, substituted C5-C6 heterocycles, azo, alkyl, amide, amine, aryl, halide, carboxylic acid, cyano, ester, and nitro groups, and fused ring systems; and (ii) R 5 is selected from the group consisting of azo, aryl, halide, carboxylic acid, cyano, ester, and nitro groups; and other electron withdrawing substituents; said method comprising: (a) stimulating the compound or material by at least a change in electric current or potential, temperature, or pH; and (b) measuring one or more optical properties of the stimulated compound or material.