Nikotinamid ve/veya Benzoat Ligandları İçeren Bazı Co(II), Zn(II) ve Mn(II) Komplekslerinin Kristal Yapı Analizi

Abstract

Nicotinamide (NA) is one form of niacin. Some benzoic acid derivatives have been extensively reported in coordination chemistry, as bifunctional organic ligands, due to the varieties of their coordination modes. The structure-function-coordination relationships of the arylcarboxylate ion in trasition metal complexes of benzoic acid derivatives may change depending on the natures and positions of the substituent groups on the benzene rings, the natures of the additional ligand molecules or solvents, and the pHs and temperatures of syntheses. While benzoate ligands may coordinate to transition metals through the oxygen atoms monodentately or bidentately, nicotinamide ligands coordinate to transition metals only through the pyridine nitrogen atoms monodentately. In this thesis, the molecular and crystal structures of some transition series metal complexes containing nicotinamide and / or benzoate ligands were determined by single crystal X-ray diffraction method. The intensity data of the complexes were collected on a Bruker SMART BREEZE CCD diffractometer. The collected data were processed by SHELXS97 and SHELXL97 programs incorporated in the WinGX package. PARST and PLATON programs were used to determine the possible intermolecular and intramolecular interactions. Chemical and molecular diagrams were drawn by CHEMWIN and ORTEP 3 programs. Unit cell parameters, space groups, atomic coordinates, anisotropic displacement parameters, bond lengths and angles between atoms, torsion angles together with the dihedral angles of the crystals were determined. It had been determined that there were disordered atoms in two of the structures to be solved. Three of the structures solved were centrosymmetric. It has been determined that ligands are bonded to metal atoms monodentately or bidentately. It was also determined that in all of the structures, the near equalities of the C-O bonds in the carboxylate groups indicated delocalized bonding arrangements rather than localized single and double bonds. It was observed that in six of the structures the coordinations around the transition metal atoms were slightly distorted octahedrals. By taking into account the possible intra- and intermolecular hydrogen bonds together with the possible C–H···π and π–π interactions, the possible ring motifs were determined. The solved structures were reported in Acta Crystallographica, Section E indexed by Web of Science.