Synthesis and characterization of picolinate-containing nickel(II) complexes with tridentate and tripodal tetradentate ligands

Two picolinate-containing nickel(II) complexes [Ni(bbma)(pic)(H2O)]ClO4 center dot CH3OH (1) and [Ni(ntb)(pic)]Cl center dot CH3OH center dot 3H2O (2) were synthesized and characterized by infrared, elemental analysis, UV-Vis, and X-ray diffraction analyses, where bbma is bis(benzimidazol-2-yl-methyl)amine, ntb is tris(2-benzimidazolylmethyl)amine, pic is the anion of picolinic acid. X-ray analysis shows that both complexes are mononuclear with picolinate coordinated to Ni(II) in a 2-N,O chelating mode. Both complexes adopt distorted octahedral geometry. Intermolecular N-H center dot center dot center dot O and O-H center dot center dot center dot O hydrogen bonds and - interactions in 1 and 2 are important in stabilization of the crystal structures.