1 Centre National de la Recherche Scientifique, Laboratoire de Chimie de Coordination (LCC/CNRS/UPR8241), 205, route de Narbonne, 31077, Toulouse Cedex, France.
A cooperative spin transition behaviour with a wide hysteresis loop (30 K) around 240 K has been observed, for the first time, in a salt based on the redox active [Ni(dmit)(2)](-), anion and the [Fe(sal(2)-trien)](+) spin crossover cation.