2-[2-[2-Chloro-3-[2-[...]-ethylidene]-1-cyclohexen-1-yl]-ethenyl]-3,3-dimethyl-1-(4-sulfobutyl)-3H-indolium hydroxide, inner salt, sodium salt

sodium;4-[2-[2-[2-chloro-3-[2-[3,3-dimethyl-1-(4-sulfonatobutyl)indol-1-ium-2-yl]ethenyl]cyclohex-2-en-1-ylidene]ethylidene]-3,3-dimethylindol-1-yl]butane-1-sulfonate