Novel cobalt(II), nickel(II) and copper(II) complexes of neutral orotic acid.: Synthesis, spectroscopic and thermal studies

The new orotic acid complexes, [MCl2(H2O)(3)(H(3)Or)], M=Co(II), Ni(II) and [CuCl2(H2O)(H(3)Or)(3)] center dot H2O, were synthesized and characterized by elemental analysis, magnetic susceptibility, spectral (Diffuse reflectance UV-Vis and FTIR) methods, and simultaneous thermal analysis (TG, DTG and DTA) techniques. Physical measurements indicate that the neutral orotic acid ligands are bonded to metal ions through the carbonyl groups. Two thermal processes of the complexes can occur: dehydration and pyrolytic decomposition. On the basis of the DTG(max), the thermal stability of the complexes follows the order: Co(II) (122 degrees C) > Cu(II) (77 degrees C) > Ni(II) (66 degrees C).