Influence of the molecular structures of dithiolate ligands on crystal packing modes and magnetic properties in salts (Bz-Et₃N)[Ni(dmit) _x(mnt)_2-x] (x = 0-2)

Nickel-bis-dithiolene salts, (Bz-Et₃N)[Ni(dmit) _x(mnt)_2-x] (x = 0-2 for 1-3 and mnt^2- = maleonitriledithiolate, dmit^2- = 2-thioxo-1,3-dithiole-4,5- dithiolate), have been prepared and characterized. These three salts exhibit distinct anion packing structures and magnetic properties. [Ni(mnt) ₂]^- anions, in which the mnt^2- ligand has a reduced number of sulfur atoms, form one-dimensional anion stacks in 1. Conversely, [Ni(dmit)₂]^- anions, in which the dmit ^2- ligand contains extended SR groups, give rise to a layered structure in 2; the anion layer is composed of co-facial [Ni(dmit) ₂]^- dimers, which are interconnected through short lateral-to-lateral S⋯S and head-to-tail S⋯S contacts. The heteroleptic [Ni(dmit)(mnt)]^- anions show one-dimensional anion stacking in 3. Charge-assisted H-bonds are formed between the CN groups of the mnt^2- ligands and the H atoms of the cations in 1 and 3 and between the terminal S atoms of the dmit^2- ligands and the H atoms of the cations in 2. Both 1 and 3 show antiferromagnetic chain behavior. Within the respective magnetic chains, there are much stronger antiferromagnetic interactions in 3 than in 1, and salt 2 shows antiferromagnetic dimer behavior. This journal is