3H-2a-aza-5a-azoniaacenaphthylene, 5-hydroxy-4-methyl-3-oxo-, inner salt 4-methyl-3-oxo-3H-2a-aza-5a-azoniaacenaphthylen-5-olate InChI=1/C11H8N2O2/c1-7-10(14)12-5-2-3-8-4-6-13(9(8)12)11(7)15/h2-6H,1H