A new family of diamagnetic macrocyclic Fe(II) compounds exhibiting the LIESST effect at high temperatures.

The photomagnetic properties of a new Fe(II) macrocyclic family [Fe(L(xyz)N5)(CN)2]·nH2O were investigated with respect to the T(LIESST) versus T(1/2) relationship. These compounds are diamagnetic below 400 K with T(LIESST) values above 100 K, which indicates that this family presents an unconventional LIESST effect that is much higher than the expected T0 = 180 K line for macrocyclic complexes.