High-Temperature Spin Crossover in Iron(II) Complexes with 2,6-Bis(1H-imidazol-2-yl)pyridine

Novel iron(II) coordination compounds containing a ligand 2,6-bis(1H-imidazol-2-yl)pyridine (L), having such a composition as [FeL2]SO4 center dot 0.5H(2)O, [FeL2]Br-2 center dot H2O, [FeL2](ReO4)(2), [FeL2]B10H10 center dot H2O, [FeL2]B12H12 center dot 1.5H(2)O had been synthesized and studied using UV-Vis (diffuse reflectance), infrared, extended X-ray absorption fine structure (EXAFS), and Mossbauer spectroscopy methods, as well as X-ray diffraction and static magnetic susceptibility methods. The analysis of the mu(eff)(T) dependence in the temperature range of 80-600 K have shown that all the obtained complexes exhibit a high-temperature spin crossover (1)A(1) <-> T-5(2).