Iron(II) pyridinecarboxamide complexes: Synthesis, crystal structures and magnetic properties

Two new mononuclear complexes of iron(II) pyridinecarboxamides (picolinamide - pia, isonicotinamide - isn), [Fe(pia)(3)]center dot(SO4)center dot 3H(2)O (1) and (isnH)(2)[Fe(isn)(2)(SO4)(2)(H2O)(2)]center dot H2O (2) have been synthesized by the reaction of iron(II) sulphate heptahydrate and pyridinecarboxamides in different solvents by standard method under reflux. Both compounds were characterized by single-crystal X-ray diffraction structure analysis, magnetic measurements and by FT-IR spectroscopy. In the complex cation of 1 Fe2+ ion is six coordinated by three nitrogen and three oxygen atoms from three bidentate picolinamide ligands in mer mode. In complex anion of 2 central Fe2+ ion is six coordinated by two isonicotinamide ligands, two sulphate ligands and two water molecules in trans mode. In both structures complex ions are connected with counterions and crystal water molecules with intermolecular hydrogen bonds. Magnetic properties of the compounds were measured between 2 K and 300 K giving the results: mu(eff) = 4.5 BM for compound 1 and mu(eff) = 4.7 BM for 2. Experimental values of the IR spectra are comparable with literature data and are in good agreement with results of the structural analysis. (C) 2022 Elsevier B.V. All rights reserved.