Irreversible Magnetic Behaviour Caused by the Thermosalient Phenomenon in an Iron(III) Spin Crossover Complex

Abstract

The new iron(III) complex [Fe(5‐I‐salEen) 2 ]ClO 4 exhibits both spin crossover, with hysteresis, between 304 K and 320 K (16 K hysteresis loop), and thermosalient phenomena. After a symmetry‐breaking phase transition between 120 and 130 K, confirmed by single‐crystal X‐ray diffraction, and the fragmentation of the crystals around 312 K, confirmed by differential scanning calorimetry and hot stage microscopy, the hysteresis loop disappears. This is the first example where the explicitly reported thermosalient effect modifies the magnetic properties of a given spin crossover crystal.