An intriguing NO2⋯π and CN⋯π interactions in [1-(4′-nitrobenzyl)pyrazinium][Ni(mnt)2]: Crystal structure, magnetic property and DFT calculation

A charge-transfer compound, [NO2BzPz][Ni(mnt)2] (NO2BzPz+ = 1-(4′-nitrobenzyl)pyrazinium and mnt2− = maleonitriledithiolate), has been structurally characterized, which shows rare noncovalently intermolecular interactions between lone-pair electron and electron-deficient pyrazine rings (NO2⋯π and CN⋯π), theoretical analysis reveals that such intermolecular interactions can be attributed to Coulomb interaction. The paramagnetic [Ni(mnt)2]− anions in [NO2BzPz][Ni(mnt)2] form a dimerized stack and strong antiferromagnetic coupling interaction is observed in such a spin dimer which lead to weak paramagnetic feature in this compound.