Patent ID: 7172907

Claim:
A dye of formula (1): wherein: groups R 3 and R 4 are attached to the Z 1 ring structure and groups R 5 and R 6 are attached to the Z 2 ring structure, and n=1, 2 or 3; Z 1 and Z 2 independently represent the atoms necessary to complete one ring, or two fused ring aromatic or heteroaromatic systems, each ring having five or six atoms selected from carbon atoms and optionally no more than two atoms selected from oxygen, nitrogen and sulphur; X and Y are the same or different and are selected from oxygen, sulphur, â€”CHâ•CHâ€” and the group: at least one of groups R 1 , R 2 , R 3 , R 4 , R 5 , R 6 (and R 8 and R 9 if present) is the group -E-F where E is a spacer group having a chain from 1â€“20 atoms selected from the group consisting of carbon, nitrogen, oxygen, sulphur and phosphorus atoms and F is a reactive group selected from succinimidyl ester, sulpho-succinimidyl ester, isothiocyanate, maleimide, haloacetamide, acid halide, hydrazide, vinylsulphone, dichlorotrazine and phosphoramidite; one of groups R 7 is selected from â€”CN and â€”CF 3 ; remaining groups R 7 are hydrogen or two of R 7 together with the group: form a hydrocarbon ring system which may optionally contain a heteroatom selected from â€”Oâ€”, â€”Sâ€”, or >NH and n is hereinbefore defined; when any of groups R 3 , R 4 , R 5 and R 6 is not said group -E-F, said remaining groups R 3 , R 4 , R 5 and R 6 are independently selected from hydrogen, halogen, hydroxyl, amino, mono- or di-C 1 â€“C 4 alkyl-substituted amino, sulphydryl, nitro, mono- or di-nitro substituted benzyl, carboxyl, C 1 â€“C 6 alkoxy, C 1 â€“C 6 alkyl, aryl, heteroaryl, aralkyl, sulphonate, sulphonic acid, quaternary ammonium and the group â€”(CH 2 ) k â€”W; when any of groups R 8 and R 9 is not said group -E-F, said remaining groups R 8 or R 9 are independently selected from C 1 â€“C 4 alkyl and â€”(CH 2 ) k â€”W; when any of groups R 1 and R 2 is not said group -E-F, said remaining groups R 1 or R 2 are selected from hydrogen, C 1 â€“C 6 alkyl, benzyl, mono- or di-nitro-substituted benzyl and â€”(CH 2 ) k â€”W; wherein W is selected from sulphonate, sulphonic acid, quaternary ammonium and carboxyl; and k is an integer from 1 to 6.