Syntheses, crystal structures and properties of two new ion-pair complexes by self-assembly of bis(maleonitriledithiolate)copper(II)/nickel(III) anion and substituted 4-dimetylaminopyridinium

► Two ion-pair complexes containing [Ni(mnt)2]− anion were successfully obtained. ► The anions and the cations in 1 stack alternately into a 1D column. ► The anions and the cations in 2 stack into segregated columns. ► The Ni(III) ions of 2 form a uniform 1D zigzag magnetic chain. ► Complex 2 shows interesting characteristic of spin-gap.