An interesting magnetic behavior in molecular solid containing one-dimensional Ni(III) chain

The preparation, crystal structure and magnetic properties of a new ion-pair complex, [BrFBzNH2Py][Ni(mnt)2] (1) [BrFBzNH2Py+ = 1-(4′-bromo-2′-flurobenzyl)-4-aminopyridinium, mnt2− = maleonitriledithiolate] are reported. The Ni ( mnt ) 2 - anions and [BrFBzNH2Py]+ cations of 1 form completely segregated uniform stacking columns. The intrachain Ni⋯Ni separation is 4.045 Å in the Ni ( mnt ) 2 - stacking column. Magnetic susceptibility measurements for 1 in the temperature range 2.0–300 K show the occurrence of significant ferromagnetic interaction in the high-temperature phase (HT), spin gap in the low-temperature phase (LT) and weak ferromagnetism due to spin canting below 5 K.