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 20–300K.•Compound 3 and 4 exhibit characteristic of antiferromagnetic coupling.