InChI=1S/C18H13ClN2O6S/c1-9-6-15(28(25,26)27)14(8-13(9)19)20-21-16-11-5-3-2-4-10(11)7-12(17(16)22)18(23)24/h2-8,22H,1H3,(H,23,24)(H,25,26,27)/b21-20+