Structural and magnetic properties of cobalt(II) complexes with pyridinecarboxamide ligands

The synthesis and characterization of two new cobalt(II) coordination compounds with nicotinamide (nia) and isonicotinamide (isn) are reported. The products were characterized magnetically, structurally by single-crystal X-ray diffraction analysis and spectrally by FT-IR spectroscopy. Using the reaction of cobalt(II) acetate tetrahydrate and nicotinamide in methanol we obtained light-red crystals of the mononuclear complex [Co(nia)(2)(H2O)(4)](CH3COO)(2)center dot 2H(2)O (1). The synthesis in a system cobalt(II) acetate dihydrathe, isonicotinamide and dimethylformamide-methanol mixture gave a new dinuclear coordination compound with the formula [Co-2(CH3COO)(4)(isn)(4)]center dot 2C(3)H(7)NO (2). In both compounds a trans arrangement of pyridinecarboxamide ligands was found. Intermolecular hydrogen bonds in the crystal structures of both complexes are discussed. The magnetic properties were studied between 2 K and 300 K giving the result mu(eff) = 4.6 BM for 1 and mu(eff) = 4.7 BM for 2 in the paramagnetic region. (C) 2014 Elsevier B.V. All rights reserved.