Two 1-D and 2-D cobalt(II) complexes: synthesis, crystal structures, spectroscopic and electrochemical properties

Two new cobalt(II) complexes, [Co(L3)2]·CH3OH·CH3COCH3 (1) (HL3 = 1-(2-{[(E)-3,5-dichloro-2-hydroxybenzylidene]amino}phenyl)ethanone oxime) and Co(L4)2 (2) (HL4 = 1-(2-{[(E)-3,5-dibromo-2-hydroxybenzylidene]amino}phenyl)ethanone oxime), have been synthesized via complexation of Co(II) acetate tetrahydrate with HL1 and HL2. HL1, HL2, and their corresponding Co(II) complexes were characterized by IR, 1H NMR spectra, as well as by elemental analysis and UV–Vis spectroscopy, respectively. The crystal structures of the complexes have been determined by single-crystal X-ray diffraction. 1 and 2 display that extensive hydrogen bonds and C–X···π bonding interactions construct the 1-D infinite chain [Co(L3)2]·CH3OH·CH3COCH3 and Co(L4)2 into 2-D supramolecular frameworks. The electrochemical properties of two Co(II) complexes were also investigated by cyclic voltammetry.