A hybrid magnet with coexistence of ferromagnetism and photoinduced Fe(III) spin-crossover

The insertion of a [Fe(sal(2)-trien)](+) complex cation into a 2D oxalate network results in a hybrid magnet with coexistence of magnetic ordering and photoinduced spin-crossover (LIESST effect) in compound [Fe-III(sal(2)-trien)][(MnCrIII)-Cr-II(ox)(3)]center dot(CH2Cl2) (1). A complete photomagnetic characterization together with a detailed structural analysis of the low-spin (LS) and high-spin (HS) structures of 1 is presented in order to understand such unusual behavior. This very rare and unexpected property in a Fe-III spin-crossover complex, has been attributed to the strong distortion exhibited by the metastable HS state. Furthermore, 1 has shown that, in contrast to what has been previously proposed, a cooperative spin-crossover is not a necessary condition to observe LIESST effect in Fe-III compounds. The photo-induced spin conversion of the inserted Fe-III complex has shown to have a negligible influence on the cooperative magnetic behaviour of the 2D oxalate network.