New Fe(II) complexes with Schiff base ligand: Synthesis, spectral characterization, magnetic studies and thermal stability

New ligand (2)-2-(1-methyl-2-(pyridine-2-ylmethylene)hydrazinyl)benzoxazole (L) reacts with Fe(II) ions what results in formation of mononuclear complexes of 2:1 stoichiometry (complexes 1 and 2), which crystallize in the rare space group la-3d (No. 230) with solvent-acetonitrile-molecules in the crystal structure. Obtained complexes were studied in terms of their properties in the solid state concerning thermal stability and magnetism. N-3-donor Schiff base type Lisa strong crystal field ligand, therefore both obtained Fe(II) complexes are diamagnetic at room temperature what has been confirmed by magnetic susceptibility measurements and Mossbauer spectroscopy. However, the reversible LS ((1)A(1)) <-> HS (T-5(2)) spin-transitions may be observed starting above room temperature, remaining incomplete even up to 400 K. The thermal stability and electronic reflectance spectra of complexes were determined as well. (C) 2015 Elsevier Ltd. All rights reserved.