Synthesis, crystal structure and magnetic property of a new 1D molecular material [1-(4′-chlorobenzyl)-4-aminopyridinium](+) bis(maleonitriledithiolato)nickel(-)

A new ion-pair complex, [ClbzPyNH2][Ni(mnt)2], where [ClbzPyNH2]+=1-(4′-chlorobenzyl)-4-aminopyridinium and mnt2=(maleonitriledithiolate, forms completely segregated uniform stacking columns with the Ni⋯Ni distance 3.944 Å in the Ni(mnt)2- stacking column, and exhibits ferromagnetic interaction in the high-temperature phase and spin gap system in the low-temperature phase.