An intriguing NO 2⋯π and CN⋯π interactions in [1-(4′-nitrobenzyl)pyrazinium][Ni(mnt) 2]: Crystal structure, magnetic property and DFT calculation

Abstract

A charge-transfer compound, [NO 2BzPz][Ni(mnt) 2] (NO 2BzPz + = 1-(4′-nitrobenzyl)pyrazinium and mnt 2− = maleonitriledithiolate), has been structurally characterized, which shows rare noncovalently intermolecular interactions between lone-pair electron and electron-deficient pyrazine rings (NO 2⋯π and CN⋯π), theoretical analysis reveals that such intermolecular interactions can be attributed to Coulomb interaction. The paramagnetic [Ni(mnt) 2] − anions in [NO 2BzPz][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.