Dihydrogen (mu-((2,2-(vinylenebis((3-sulpho-4,1-phenylene)imino(6-chloro-1,3,5-triazine-4,2-diyl)imino(1-hydroxy-3-sulphonaphthalene-6,2-diyl)azo))bis(benzoato))(8-)))dichromate(2-)