Syntheses, crystal structures, and magnetic properties of four new molecular solids based on Ni(mnt)2− monoanion (mnt2− = maleonitriledithiolate)

Four new molecular solids, [1-(2′-F-4′-R-benzyl)pyridinium][bis(maleonitrile dithiolato)nickel] (abbreviated as [RFBzPy][Ni(mnt)2], R = F (1), Cl (2), I (3), H (4)), have been prepared and characterized. The Ni(III) ions in 1-3 form a 1D zig-zag chain within a Ni(mnt)2− column. The chain is uniform in 2 and 3, while it is alternating in 1. The cations and Ni(mnt)2 ions of 4 stack in complicated way in which the stacking of Ni(III) ions shows an ACA-type repeat unit. Magnetic susceptibility measurements in the temperature range 1.8-300 K show that 1 and 4 are diamagnetic, whereas 2 and 3 exhibit ferromagnetic coupling behavior. The χMT of 2 and 3 can be well reproduced by the Baker equation for a 1D S = 1/2 magnetic chain with g = 2.01, J = 17.8 cm−1 for 2, and g = 2.04, J = 41.1 cm−1 for 3.