The molecule is a zwitterion that is derived from 3,4-bis(7-chloroindol-3-yl)-2,5-diiminohexanedioic acid by deprotonation of both carboxylic acid groups and protonation of both amino groups; major species at pH 7.3. It is a tautomer of a 3,4-bis(7-chloroindol-3-yl)-2,5-diiminohexanedioic acid.
3,4-bis(7-chloro-1H-indol-3-yl)-2,5-diiminohexanedioic acid