Diaminomaleonitrile – Mono‐, Di‐ …and Tetraprotonation?!

Abstract The successful mono‐ and diprotonation of DAMN showed the first site of protonation to be an amino group, while the second protonation occurs at a nitrile group. The prepared salts were characterized by vibrational spectroscopy and single crystal X‐ray crystallography. Under strong superacidic conditions and with sufficient time cyclization of two (di)protonated molecules of DAMN is observed, yielding a tetracationic pyrazine species. Quantum chemical calculations are employed to explain reactivity and properties of compounds shown in the manuscript.