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

Abstract

Two picolinate-containing nickel(II) complexes [Ni(bbma)(pic)(H₂O)]ClO₄ · CH₃OH (1) and [Ni(ntb)(pic)]Cl · CH₃OH · 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 μ₂-N,O chelating mode. Both complexes adopt distorted octahedral geometry. Intermolecular N–H ··· O and O–H ··· O hydrogen bonds and π–π interactions in 1 and 2 are important in stabilization of the crystal structures.

Keywords:

• Nickel(II) complex
• Picolinic acid
• Benzimidazole
• Crystal structure

Acknowledgments

This study was supported by Beijing Natural Science Foundation (Grant no. 2092010), Beijing Municipal Education Commission research program (KM200810028009) and the Scientific Research Foundation for Returned Overseas Chinese Scholars, Beijing Municipal Government.