Investigation of the structure of some metal(II) benzimidazole compounds by vibrational spectroscopy and molecular structure and vibrational spectra of 1,2-bis(4-pyridyl) ethane by density functional theory and ab-initio hartree-fock calculations

In this study, M(benzimidazole)X2 [M =Cd, Cu; X=CI, Br ], M(benzimidazole)2 X2 [ M = Co; X=CI, Br,l ], Co(benzimidazole)2 metal halogen compounds and single crystal of Zn(benzimidazole)2Br2 have been prepared for the first time. The infrared spectra of all these compounds and the single crystal have been recorded between 4000- 200 cm"1 region. The vibrational frequencies of the free ligand molecules were compared with those complexes. The frequency shifts between free ligand and coordinated ligand were investigated. In the complex structure some shifts have been observed according to the free ligand molecules, due to the complex formation. It is commented that these shifts are metal dependent and explained by the coupling of the internal modes of ligand molecules with the M-N(ligand) vibration. The structure of the single crystal Zn(benzimidazole)2Br2 was determined by the X-ray diffraction methods. The result of the C, H, N analyses of the complexes and single crystal are also given. The bond lengths, bond angles and the vibrational IR spectra (HF/6-31G(d), B3LYP/6-31G(d) and BLYP/6-31G(d) levels of theory) of the molecule 1,2-bis-(4-pyridyl) ethane (bpa) were calculated by the programme of IV Gaussian98. The calculated parameters were compared with the experimental values Science CodeKey Words Page Number Supervisor : 404.03.01. : Benzimidazole, 1,2-bis-(4-py ridyl) ethane (bpa), metal halogen compounds, The crystal of Zn, Gaussian98, HF, DFT, Infrared Spectra :126 : Prof Dr. Şenay YURDAKUL