Patent ID: 8383841

Claim:
A fluorescent phenyl xanthene dye comprising a rhodamine that comprises one of the following core structures: wherein A is —NR 3 ′R 3 ″; wherein B is ═N + R 6 ′R 6 ″; wherein each of R 11 and R 15 is independently selected from the group consisting of an alkyl, a heteroalkyl, an alkoxy, a halo, a haloalkyl, an amino, an alkylthio, a cyano, an isocyano, a cyanato, a mercaptocyano, and a nitro; and each of R 1 , R 2 , R 2 ′, R 3 ′, R 3 ″, R 4 , R 4 ′, R 5 , R 5 ′, R 6 ′, R 6 ″, R 7 , R 7 ′, R 8 , R 12 , R 13 and R 14 is independently selected from the group consisting of hydrogen and any substituent selected from the group consisting of an alkyl, a heteroalkyl, an aryl, a heteroaryl, an alkoxy, a halo, a haloalkyl, an amino, an alkylthio, cyano, isocyano, cyanato, a mercaptocyano, nitro, sulfonamide, carboxyl, and carboxyamide, the substituent having up to 40 atoms, with the proviso that at least one of R 3 ′, R 3 ″, R 6 ′ and R 6 ″ is a lipophilic substituent selected from the group consisting of unsubstituted (C4-C20) alkyl, (C5-C40) aryl and (C6-C40) arylalkyl.