Patent ID: 8715621

Claim:
A compound represented by structural Formula (I): wherein: each R is independently —R′, —OR′, —SR′, halogen, —CN, —NO2, —NR′R″, polyethyleneglycol —COOR′, —OCOR′, —CONR′R″, or —NR′COR″, or two R on adjacent carbon atoms taken together are Z 1 -Z 5 are each independently —SO 2 X, —SO 3 X or —SO 2 NR′R″; R′ and R″ are independently —H, an optionally substituted alkyl or an optionally substituted aryl; X is a cation; a1, b1, c1 and d1 are each integers from 0 to 4, wherein the sum of a1, b1, c1and d1 is one or greater; a2, b2, c2 and d2 are each independently integers from 0 to 4; e1 and e2 are each independently an integer from 0 to 5; and j and k are independently integers from 0 to 2.