Transition metals with mixed ligand 5-aminoisophthalate complexes; syntheses, spectroscopic, thermal studies and crystal structures

In this study, mixed ligand complexes of Mn(II), Co(II) and Ni(II) transition metal ions with 5-aminoisophthalic acid (H2aif) were synthesized. As secondary ligands in the complexes, 2,2?-bipyridine (bpy), 1,10-phenanthroline (phen), ethylendiamin (en), im (imidazole), 4-meim (4-methylimidazole) ve pka (2-pyridinecarboxyaldehyde) has been chosen. The structural and spectroscopic properties of synthesized complexes were characterized by using elemental analyses, magnetic susceptibilities, FT-IR, UV-Vis. and thermal analysis techniques (TG-DTA-DTG). Structure of complexes {[Mn2( ? -aif)2(bpy)2]?(dmf)2?2H2O}n (1), [Co(pmi)(H2O)4]?3H2O (2), {[Ni( ? -aif)(H2O)2(en)]?3H2O}n (3), [Ni( ? -aif)(H2O)2(im)]n(4), [Ni(aif)(H2O)3(phen)]?2H2O (5) ve [Ni(5-meim)6]2(aif)2?8H2O (6) were identified by X-Ray single crystal method. Nickel complexes which are paramagnetic have two unpaired electrons. In the 1 complex, manganese has five unpaired electrons. In addition to spin magnetic moment, there is orbital contribution in complex 2. 1 has weak bands in the electronic spectrum in an octahedral environment because of disbanded spin and orbital transitions. Electronic spectra of 2 and 6 in DMSO exhibit two absorption bands 812 (?=13 Lmol-1cm-1) and 476 (?=61 Lmol-1cm-1) for 2, 646 (19 Lmol-1cm-1) and 490 (49 Lmol-1cm-1) for 6. In the 3 complex d-d transitions did't appeared. There are one d-d transition band in 4 and 5 complexes, 681 nm (?=14 Lmol-1cm-1) and 663 nm (?=15 Lmol-1cm-1); respectively. Distorted octahedral geometries of the complexes are completed with neutral ligands and/or aqua ligands. The complex 1 is a 2D porous coordination polymer. X-ray single-crystal diffraction study reveals that compound 2 is a Schiff base complex which has 2D metal-water cluster. A new coordination mode of aif is found in 2D polymer 3 complex. Complex 4 is a two dimensional coordination polymer. In the 6 complex, aif is not coordinated to nickel ion and this complex is a proton transfer compound.