Syntheses, crystal structures and magnetic properties of four new ion-pair complexes containing bis(maleonitriledithiolate)copper(II)/nickel(III) anion and disubstituted benzyl triphenylphosphonium

• Four molecular solids containing [Cu(mnt)2]2−/[Ni(mnt)2]− anion were synthesized and characterized.
• There are F⋯F, Cl⋯Cl and C–H⋯Cu anagostic interactions in 1 and 2.
• The Ni(III) ions in a [Ni(mnt)2]− column of 3 and 4 form a 1D linear chain.
• Compound 1 and 2 show weak ferromagnetic coupling at 20–300 K.
• Compound 3 and 4 exhibit characteristic of antiferromagnetic coupling.

Four novel ion-pair complexes, [FClBzTPP]2[Cu(mnt)2](1), [DiClBzTPP]2[Cu(mnt)2](2), [FClBzTPP][Ni(mnt)2](3) and [DiClBzTPP][Ni(mnt)2](4), where [FClBzTPP]+ = 1-(2′-chloro-4′-flurobenzyl)triphenylphosphonium, [DiClBzTPP]+ = 1-(2′, 4′-chlorobenzyl)triphenylphosphonium and mnt2− = maleonitriledithiolate, have been prepared and characterized by elemental analyses, IR, UV, single crystal X-ray diffraction and magnetic measurements. Weak interactions such as F⋯F, Cl⋯Cl, and C–H⋯N, C–H⋯Cl, C–H⋯Cu observed in 1 and 2 consolidate 3D network structure. The Ni(III) ions of 3 and 4 form a 1D linear chain in a column of [Ni(mnt)2]− anions by intermolecular Ni⋯Ni and Ni⋯S or π⋯π weak interactions. The change of 4-substituted group in the benzyl ring from F to Cl atom results in the crystal system, space group, and the stacking and overlapping modes of [Ni(mnt)2]− anions in 3 and 4. Magnetic susceptibility measurements show that 1 and 2 at 20–300 K exhibit weak ferromagnetic coupling with θ = 4.21 K and 1.80 K, whereas while 3 and 4 show antiferromagnetic coupling with J = −36.42 cm−1 and −55.78 cm−1.

Two ion-pair complexes containing bis(maleonitriledithiolate)copper(II) anion form a 3D network structure by some weak interactions, and show very weakly ferromagnetic coupling behavior at 20–300 K, whereas the Ni(III) ions in two complexes containing bis(maleonitriledithiolate)nickel(III) anion form a 1D linear chain in a [Ni(mnt)2]− column, and exhibit characteristic of antiferromagnetic coupling.Figure optionsDownload as PowerPoint slide