The carboxamide [–C(O)NH–] group, ubiquitous throughout nature in the primary structure of proteins, is an important ligand construction unit for coordination chemists. Pyridine carboxamides, a burgeoning The amide hydrogen atoms become labile when the ligand undergoes complexation, which often resulted in the formation of a mono or a dianionic ligand. Deprotonated amide groups have maximum electronic delocalization and strong ? donating properties. These groups usually coordinate via the nitrogen atom whereas coordination via oxygen is more frequent for neutral ligands. In this thesis, the synthesis of the new ligand (H 2 cbqb)(?) and its complexes [M(cbqb)] and [N(n-Bu) 4 ] [Co(cbqb)X 2 ], which may have biochemical and photochemichal applications ??) [Co(cbqb)] V?) [N(n-Bu) 4 ][Co(cbqb) (N 3 ) 2 ] ???) [Ni(cbqb)] V??) [N(n-Bu) 4 ][Co(cbqb) (CN) 2 ] ?V) [Cu(cbqb)] V) [Cd(cbqb)] are reported. The fused phenyl rings and chlorine group in the structure of cbqb, as compared with that of , increase the ? accepting character of cbqb. Consequently, the reactivity of Co II in [Co II (cbqb)] towards ? donor ligands (such as amines) is lowered. We succeeded to synthesize only complexes of two ? donor and ? acceptor ligands (CN – and N 3 – ) with strong ? accepting character in the axial positions. The (H 2 cbqb) and its complexes were characterized by UV-Vis, FT-IR, 1 H-NMR and elemental analysis. Complex (V?) was structurally characterized by X-Ray Diffraction. The electrochemical properties of complexes (V?), (V??) were also investigated by cyclic voltammetry.
