LAUSR

Four novel hetero dimetallic mixed metal complexes of 2,6-pyridinedicarboxylic acid       (H2dipic), [Ni(H2O)5Co(dipic)2] (1), [Co(H2O)5Co(dipic)2][Ni(H2O)5Ni(dipic)2][Co(dipic)(H2O)3] (2), [Cu(H2O)5Ni(dipic)2]2[Co(dipic)(H2O)] (3) and [Ni(H2O)5Cu(dipic)2]2[Co(dipic)(H2O)] (4) have been prepared and characterized by elemental, AAS, spectral (IR and UV-Vis), and thermal analyses, as well as by using magnetic measurement and molar conductivity techniques. The results indicate that metal ions coordinate with 2,6-pyridinedicarboxylate ions (dipic2-) nitrogen atoms and carboxylate oxygen atoms of ligands. The mole ratio of dipic2- and metal ions in the complexes have been determined to be 2:2 (Co, Ni) for 1, 5:5 (3Co, 2Ni) for 2, 5:5 (Co, 2Ni and 2Cu) for 3 and 5:5 (Co, 2Ni and 2Cu) for 4 according to the results of elemental analysis. The structures of 1-4 might be proposed as octahedral ([Cu(dipic)(H2O)] unit for 2 square plane) according to results of spectroscopic analysis. The TG and DTA properties of compounds have been studied.                     KEY WORDS: 2,6-Pyridinedicarboxylic acid, Mixed metal, Metal complex   Bull. Chem. Soc. Ethiop. 2020, 34(2), 313-321 DOI: https://dx.doi.org/10.4314/bcse.v34i2.9