OXALATE-2-ETHANOLAMINE COMPLEXES OF SOME BIVALENT-CATIONS (MN, CO, NI, CU, ZN AND CD)

On the refluxing of M(II) oxalate (M = Mn, Co, Ni, Cu, Zn or Cd) and 2-ethanolamine in chloroform, the following complexes were obtained: MnC2O4 . HOCH2CH2NH2H2O, CoC2O4 . 2HOCH(2)CH(2)NH(2), Ni-2(C2O4)(2) . 5HOCH(2)CH(2)NH(2) . 3H(2)O, Cu-2(C3O4)(2) . 5HOCH(2)CH(2)NH(2), Zn-2(C2O4)(2) . 5HOCH(2)CH(2)NH(2) . 2H(2)O and Cd-2(C2O4)(2) . HOCH2CH2NH2 . 2H(2)O. Following the reaction of M(II) oxalate with 5-ethanolamine in the presence of ethanolammonium oxalate, a compound with the empirical formula ZnC2O4 . HOCH2CH2NH2 . 2H(2)O(1) was isolated. The complexes were identified by using elemental analysis, X-ray powder diffraction patterns, IR spectra, and thermogravimetric and differential thermal analysis. The IR spectra and X-ray powder diffraction patterns showed that the complexes obtained were not isostructural. Their thermal decompositions, in the temperature interval between 20 and about 900 degrees C, also take place in different ways, mainly through the formation of different amine complexes. The DTA curves exhibit a number of thermal effects.