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The coumarilate (coum−) and 1,10-phenanthroline (phen) mixed ligand complexes of Co(II) (1), Ni(II) (2) Cu(II) (3) and Zn(II) (4) were synthesized and structural characterizations were performed by using elemental analysis, magnetic susceptibility, solid-state UV–Vis, FTIR spectra, thermoanalytical TG-DTG/DTA and single-crystal X-ray diffraction methods. The Co(II) and Ni(II) complexes are salt-type compounds, and they have two moles phen ligands bound as bidentate, two moles aqua ligands in coordination sphere and two moles anionic coum− ligand outside of the coordination unit as the counter-ion of the molecular structure. At the same time, the Co(II) and Ni(II) complexes have five moles of aqua ligands as hydrated water outside of the molecules. It was obtained that Cu(II) and Zn(II) complex structures contain one mole of phen ligand, two moles coordinated (coum−) ligand and a one-mole aqua ligand, and the molecules (Cu(II) and Zn(II)) have fivefold structure and obey square pyramidal geometry. Thermal decomposition of each complex started with dehydration (the first removal is the dehydration of complex Co(II) and Ni(II) as removal of hydrate–aqua molecules), and then, the decomposition of organic parts was observed. The thermal dehydration of the complexes takes place in one (Cu(II) and Zn(II)) or two (Co(II) and Co(II)) steps. The decomposition mechanism, thermal decomposition steps and thermal stability of the investigated complexes provide useful data for the interpretation of their structures. The final decomposition products were found to be metal oxides. Some biological applications (antifungal/antibacterial) were performed using structurally characterized compounds. [ABSTRACT FROM AUTHOR]

The coumarilate (coum) complexes of Co( 1), Ni( 2) Cu( 3) and Zn( 4) were synthesized and characterized by elemental analysis, magnetic susceptibility, solid-state UV-Vis, FTIR spectra, thermoanalytical TG-DTG/DTA and single-crystal X-ray diffraction methods. It was found that all of the complex structures have 2 mol (coum) ligand bonded as monoanionic monodentate in the structures of 1 and 2 while they were coordinated to metal cations as monoanionic bidentate in the complexes 3 and 4. There was not any hydrate water in the metal complexes. The complexes of 1 and 2 have four moles of aqua ligand, and the other complexes have two moles. Thermal decomposition of each complex starts with dehydration, and then the decomposition of organic parts goes. The thermal dehydration of the complexes takes place in one (for the compounds of 2, 3, 4) or two (for the compound 1) steps. The decomposition mechanism and the thermal stability of the complexes under investigation were determined on the basis of their structures. Metal oxides were obtained as the final decomposition product. [ABSTRACT FROM AUTHOR]