tetralithium 7,7'-[carbonylbis[imino(5-methoxy-2-methyl-4,1-phenylene)azo]]bis(naphthalene-1,3-disulphonate)

7,7'-[Carbonylbis[imino(5-methoxy-2-methyl-4,1-phenylene)azo]]bis(1,3-naphthalenedisulfonic acid dilithium) salt