Synthesis and characterization of homophtlate complexes with manganese(II), nickel(II) and copper(II)

In this study, mixed ligand complexes of Mn(II), Ni(II) and Cu(II) transition metal ions with homophthalic acid (H2hmph) were synthesized. As secondary ligands, 2,2'-bpyridine (2,2'-bpy), N,N-dimetyletane-1,2-diamine (dmen), im (imidazole) and 1,10-phenanthroline (phen) have been used. The structural and spectroscopic properties of synthesized complexes were characterized by using X-ray single crystal method, elemental analyses, magnetic susceptibilities, FT-IR, UV-Vis. and thermal analysis (TG-DTA-DTG) techniques. Structure of complexes [Mn(µ-hmph)(H2O)2(bipy)]n (1), [Ni(hmph)(H2O)(dmen)2]•H2O (2), [Cu(µ3-hmph)(im)2]n (3) ve [CuCl(phen)2](Hhmph)∙(H2hmph) (4) were identified by X-Ray single crystal method. In the 1 complex manganese has five unpaired electrons. 1 has weak bands in the electronic spectrum in an octahedral environment because of disbanded spin and orbital transitions. Electronic spectra of complex 2 exhibits two absorption d-d transition band in 642 nm (ε = 6 Lmol-1cm-1) and 363 nm (ε = 23 Lmol-1cm-1). Electronic spectra of Cu(II) complexes 3 and 4 exhibit one absorption d-d transition band in 692 nm (ε = 16 Lmol-1cm-1) and in 716 nm (ε = 16 Lmol-1cm-1), respectively. Octahedral geometries of the complexes 1 and 2 are completed with neutral ligands and aqua ligands. Distorted square-pyramidal geometry of complex 3 and pair of triangular-pyramid geometry of complex 4 are completed with neutral ligands. Also 1D for complex 1 and 2D for complex 3 are identified to exhibit coordination polymers. For complex 4, one Hhmph ligand exists lost one proton and H2hmph ligand exists unprotoned form out side of the coordination sphere.