THERMAL-BEHAVIOR OF METAL-COMPLEXES WITH ISOOROTATE AND 2-THIOISOOROTATE DIANIONS

The thermal behaviour of M(II) (HL).xNH3.yH2O complexes (HL = isoorotate and 2-thioisoorotate; M = Mn, Ni, Cu, Zn, Cd, Hg) has been established by TG, DTG and DSC methods. The thermal decomposition of these compounds takes place through two major steps. The first is loss of solvent molecules and this is followed by decarboxylation and pyrolytic decomposition. TG and DSC data suggest that solvent molecules are not structurally well defined, in spite of the fact that spectral data indicate that in most cases these water and ammonia molecules are coordinated to the metal ion. Wherever possible, the nature of intermediate products and residues was investigated by infra-red spectrometry.