New iron(II) complexes Fe(HC(Pz)_3)_2A_2 with spin-crossover

摘要

Three new coordination compounds of iron(II), [Fe(HC(Pz)_3)_2](C_8H_5O_4)_2·C_8H_6O_4 (I), [Fe(HC(Pz)_3)_2](C_(10)H_7SO_3)_2.2H_2O (II) and Fe(HC(Pz)_3)_2](C_(12)H_(25)SO_4))_2 (III), where HC(Pz)_3 is the tridentate chelator tris(pyrazol-1-yl)methane, have been synthesized and investigated by X-ray structure analysis, electronic and IR spectroscopy, static magnetic susceptibility method. The magnetochemical study of complexes I–III in the interval from 300 to 500 K showed that they possessed the high-temperature spin crossover ~1(A_1) → ~5(T_2) accompanied by thermochromism (the pink → white color change).