Redox-active structures and devices utilizing the same

A device having reversibly changeable and optically readable optical properties, the device comprising a substrate having an electrically conductive surface and carrying a metal-based redox-active layer structure configured to have at least one predetermined electronic property including at least one of electrodensity and oxidation state, said at least one electronic property being changeable by subjecting the layer structure to an electric field, wherein the electronic property of the layer structure defines an optical property of the structure thereby determining an optical response of the structure to certain incident light, the device enabling to effect a change in said electronic property that results in a detectable change in the optical response of the layer structure, wherein said redox-active layer structure comprises at least one charged tris-bipyridyl metal complex of the formula II:

• wherein
• M is a metal selected from the group consisting of Os, Ru, Fe, Cu, and Co;
• n is the formal oxidation state of the metal, wherein n is 0-4;
• X is a counter anion selected from the group consisting of Br−, Cl−, F−, I−, PF6−, BF4−, OH−, ClO4−, SO3−, CF3COO−, CN−, alkylCOO−, arylCOO−, and any combination thereof;
• R4 to R27 each independently is selected from the group consisting of hydrogen, halogen, hydroxyl, azido, nitro, cyano, amino, substituted amino, thiol, C1-C10 alkyl, cycloalkyl, heterocycloalkyl, haloalkyl, aryl, heteroaryl, alkoxy, alkenyl, alkynyl, carboxamido, substituted carboxamido, carboxyl, protected carboxyl, protected amino, sulfonyl, substituted aryl, substituted cycloalkyl, substituted heterocycloalkyl, and group A, wherein at least one of said R4 to R27 is a group A:
• wherein A is linked to the ring structure of the compound of general formula II via R3;
• R3 is selected from the group consisting of cis/trans C═C, C≡C, N═N, C═N, N═C, C—N, N—C, alkylene, arylene and any combination thereof;
• R2 is selected from the group consisting of alkyl, alkylene, aryl, arylene and any combination thereof;
• R1 is absent or is selected from the group consisting of hydrogen, trialkoxysilane, trihalidesilane, thiol, COOH, COO−, Si(OH)3 and phosphonate;
• and any two vicinal R4-R27 substituents, together with the carbon atoms to which they are attached, may form a fused ring system selected from the group consisting of cycloalkyl, heterocycloalkyl, heteroaryl and aryl, wherein said fused system may be substituted by one or more groups selected from the group consisting of C1-C10 alkyl, aryl, azido, cycloalkyl, halogen, heterocycloalkyl, alkoxy, hydroxyl, haloalkyl, heteroaryl, alkenyl, alkynyl, nitro, cyano, amino, substituted amino, carboxamido, substituted carboxamido, carboxyl, protected carboxyl, protected amino, thiol, sulfonyl and substituted aryl;
• and said fused ring system may also contain at least one heteroatom selected from the group consisting of N, O and S;
• and
• m is the number of A groups.