Acid/Base versus Redox Reaction−The Case of Chloranilic Acid and Hydrazine: A Supramolecular Decision?

The reaction between the oxidative chloranilic acid and the reductive base hydrazine can in principle follow either of two pathways, a redox or a neutralization reaction. We anticipated the redox reaction and were quite surprised to obtain the salt instead. However, after the salt's crystal structure was solved, it was quite obvious that the reaction is supramolecularly controlled by the formation of a three-dimensional charge-assisted hydrogen bond network between the “polymeric” hydrazinium cations and the parallel π−π stacks of chloranilate anions.