Patent ID: 8664410

Claim:
A fluorescent dye according to general formula I or II: wherein R 1 and R 2 are independently selected from the group consisting of hydrogen or a branched or unbranched, saturated or unsaturated, aliphatic or aromatic, functionally substituted, or unsubstituted hydrocarbon radical, alkoxy radical, ether radical, alkoxyether radical, acyl radical, ketone radical, carboxylic acid radical, carboxylic ester radical, or aldehyde radical, wherein at least one of the R 1 or R 2 radicals is not hydrogen; R 3 and R 4 are independently selected from the group consisting of a C 2 -C 20 acyl radical, a C 2 -C 20 acylaryl radical, a C 2 -C 20 acylalkenyl radical, a C 2 -C 20 acylalkynyl radical or a nitro group, and the R 1 and R 3 radicals and/or R 2 and R 4 radicals in formula I can be bridged to each other; and X and Y independently represent a substituted or unsubstituted C 1 hydrocarbon radical or an N or S heteroatom.