Patent ID: 8016895

Claim:
A compound of formula (I) D-L-CHQ-CH 2 —SR (I) wherein D is a chromophore; L is a linking group selected from SO 2 , NHCO, and NHSO 2 ; Q is a hydrogen or halogen atom; and R is selected from C 1 -C 4 alkyl, (CH 2 ) n COOH, (CH 2 ) n CONH 2 , (CH 2 ) n SO 3 H, (CH 2 ) n COOM, (CH 2 ) n PO 3 H, (CH 2 ) n OH, (CH 2 ) n SSO 3 − , (CH 2 ) n NR 1 2 , (CH 2 ) n N + R 1 H 2 , (CH 2 ) n NHCOR 1 , PhSSO 3 − , PhSO 3 H, PhPO 3 H, PhNR 1 2 , PhN + R 1 3 , (CH 2 ) 2 CH(SH)R 1 (CH 2 ) 3 COOH, and n is an integer in the range of 1 to 4 wherein within the same molecule each n is not necessarily the same integer; M is a cation of an alkaline earth metal, alkali metal, NH 4 + or NR 1 3 + ; and R 1 is C 1 -C 4 alkyl.