72986-72-2 Chromate(2-), (7-amino-4-(hydroxy-kappaO)-3-((2-(hydroxy-kappaO)-4-nitrophenyl)azo-kappaN1)-2-naphthalenesulfonato(3-))(1-((2-(hydroxy-kappaO)-5-nitrophenyl)azo-kappaN1)-2-naphthalenolato(2-)-kappaO)-, dihydrogen