LAUSR

Abstract In this study, a benzimidazole ligand (L) containing two heptyl chains and its transition metal [Mn(II), Fe(II), Co(II), Ni(II), Cu(II) and Zn(II)] complexes were prepared and characterized by spectroscopic and analytical methods. Molecular structures of the complexes [Mn(L)Cl2], [Co(L)Cl2], [Cu(L)Cl2] and [Zn(L)Cl2] were determined by X-ray diffraction studies. In the structure of the complexes, metal ions are five-coordinate with distorted square pyramidal geometry. X-ray structural data showed the alignment of the heptyl aliphatic chains and the bond angles between the two coordinated chloride angles (Cl-M-Cl) have an effect on the crystal packing of the complex molecules. The ligand-based emission band showed a red-shift in the spectra of [Fe(L)Cl2] and [Zn(L)Cl2] complexes. Finally, thermal behaviours of the ligand and its metal complexes were studied under nitrogen atmosphere. The complexes were found to decompose at higher temperatures than that of the ligand.