tetralithium 4-amino-6-[[4-[2-[4-[(2,4-diaminophenyl)azo]-2-sulphonatophenyl]vinyl]-3-sulphonatophenyl]azo]-5-hydroxy-3-[(4-nitrophenyl)azo]naphthalene-2,7-disulphonate

4-Amino-6-[4-[2-[4-(2,4-diaminophenylazo)-2-(lithiosulfo)phenyl]ethenyl]-3-(lithiosulfo)phenylazo]-5-hydroxy-3-(4-nitrophenylazo)-2,7-naphthalenedisulfonic acid dilithium salt