Patent ID: 8846925

Claim:
A compound of the formula: wherein R 1 is hydrogen or sulfonic acid; R 2 is selected from the group consisting of hydrogen, cyano, halogen, carboxylic acid, sulfonic acid, C 1 -C 6 alkyl, C 1 -C 6 alkoxy, aryl, and heteroaryl, wherein said alkyl or alkoxy is optionally substituted by carboxylic acid, sulfonic acid, or halogen and said aryl or heteroaryl is optionally substituted one or more times by C 1 -C 6 alkyl, C 1 -C 6 perfluoroalkyl, cyano, halogen, azido, carboxylic acid, sulfonic acid, or halomethyl; R 3 and R 4 are each methyl; R 5 is selected from the group consisting of hydrogen, methyl, carboxymethyl, C 2 -C 6 alkyl, aryl, heteroaryl, wherein said alkyl is optionally substituted by carboxylic acid, sulfonic acid, amino, or halogen and said aryl or heteroaryl is optionally substituted one or more times by C 1 -C 6 alkyl, C 1 -C 6 perfluoroalkyl, cyano, halogen, carboxylic acid, sulfonic acid, or halomethyl; R 6 and R 7 are both hydrogen; one of X and E is O, S, or NR 8 , and the other is absent; wherein R 8 is independently selected from the group consisting of hydrogen, methyl, carboxymethyl, C 2 -C 6 alkyl, -L-R x , and -L-S c , wherein said alkyl is optionally substituted by carboxylic acid, sulfonic acid, amino, or halogen; Y is independently selected from the group consisting of H, OH, NH 2 , NO, —(CO)—R 9 , —(CO)—O—R 10 , wherein R 9 and R 10 are independently H, C 1 -C 6 alkyl, or a substituted or unsubstituted aryl or heteroaryl ring system having 1-2 rings; and Z is OH; wherein L is a covalent linkage; R x is a reactive group selected from the group consisting of an acrylamide, an activated ester of a carboxylic acid, an acyl azide, an acyl nitrile, an aldehyde, an alkyl halide, an amine, an anhydride, an aniline, an aryl halide, an azide, an aziridine, a boronate, a carboxylic acid, a diazoalkane, a haloacetamide, a halotriazine, a hydrazine, an imido ester, an isocyanate, an isothiocyanate, a maleimide, a phosphoramidite, a reactive platinum complex, a sulfonyl halide, and a thiol group; and S c is a conjugated substance.