Zwitterionic Diazonium Salts and Their Peroxosolvates: Peculiarities of Non-Covalent O:→+N2−Ar Interactions

Abstract Two-component crystals composed of potentially unstable species, namely, zwitterionic diazonium salts and hydrogen peroxide, were obtained and structurally characterized. Very unusual intermolecular bonds were observed, with the highlight being oxygen from the peroxide (often not a strong donor) interacting with the diazonium cation. Similar intramolecular interactions were also observed in the crystals of unsolvated diazonium salts. The existence of these bonds (interactions) was confirmed by the presence of the bond’s critical points (3,-1), found by means of Bader analysis of the calculated crystalline electron density. At the shortest contact, the O···N distance reaches ∼2.68 Å, and the energy is ∼15 kJ/mol. Such specific properties allow us to define these interactions as non-covalent O: →+N2−Ar interactions.