The thermodynamic and thermal properties of [Cu(L)2·Cl2], [Ni(L)2]·Cl2, [Co(L)2·Cl2]; L=1,2-bis(o-aminophenoxy)ethane (BAFE), complexes have been investigated. The thermal decomposition of the complexes took place in two distinct steps in endothermic reaction up to 700°C. The activation energy E, the entropy change
H change and Gibbs free energy change
G# were calculated from the results of thermogravimetry analysis (TG) and heat capacity from the results of differential scanning calorimetry (DSC). It was found that the thermal stabilities and activation energies of the complexes follow the order Ni(II)>Cu(II)>Co(II) and ECo<ENi<ECu, respectively.
The thermal behavior of copper(II), nickel(II) and palladium(II) complexes with two anionic varieties of 2-OH-aryloximes (ox),
[M(ox)2] (2-hydroxypropiophenonoxime and 2-hydroxy-4-methoxy-benzophenonoxime) was studied by using simultaneous TG/DTG-DTA technique
under nitrogen in the temperature range 40-700C. The behavior was compared with that in static air, which had been previously
studied. It was found that the metal, the substituents on the ligand and the heating rate influenced their thermal decomposition.
The thermal stability of the complexes with the same ligand depended on the metallic cation, following the order Pd(II)>Ni(II)>Cu(II).
It also depended on the type of ligand, increasing with bulky substituents on the oximic carbon and the benzene ring. The
sample mass almost did not affect their decomposition mode. The residues at 700C of all complexes consisted of a carbonaceous
oxide, determined by energy dispersive spectrometry (EDS) and IR spectroscopy
Authors:Yu. Goltsov, L. Matkovskaya, V. Il'in, and V. Golovaty
The results of investigation of the influence of encapsulation on the mechanism of thermal decomposition of cyanide transition
metal complexes, based on data obtained by methods of differential thermal analysis (inert atmosphere) and thermodesorption
(mass-spectral monitoring of gaseous products) are represented. It was established, that encapsulation of cyanide iron(II)
and cobalt(III) complexes in faujasite type zeolite results in the hydrolytic mechanism of thermal destruction of complexes,
unlike to bulk analogues, which is determined by essential decreasing of the temperature of complex anions encapsulated destruction
beginning, up to temperatures while zeolite water molecules are saved; the gaseous products of thermal destruction composition
is determined by the peculiarities of localization of cations of different nature in inclusion compounds.
Authors:K. Mészáros-Szécsényi, E. Ivegeš, V. Leovac, A. Kovács, G. Pokol, and Ž. Jaćimović
Complexes represented by the general formula [MCl2L2] (M(II)=Zn, Mn, Co) and complexes of [Cu3Cl6L4] and CuSO4L24H2O, CoSO4L23H2O, [ZnSO4L3] where L stands for 3-amino-5-methylpyrazole were prepared. The complexes were characterized by elemental analysis, FT-IR
spectroscopy, thermal (TG, DTG, DSC and EGA) methods and molar conductivity measurements. Except for the Zn-complexes, the
magnetic susceptibilities were also determined.
Thermal decomposition of the sulphato complexes of copper(II) and cobalt(II) and the chloro complexes of cobalt(II) and manganese(II)
resulted in well-defined intermediates. On the basis of the IR spectra and elemental analysis data of the intermediates a
decomposition scheme is proposed.
Authors:Katalin Mészáros Szécsényi, V. Leovac, R. Petković, Ž. Jaćimović, and G. Pokol
The deaquation of two isostructural compounds of general formula [M(HL)2(H2O)2](NO3)2 (M=Co, Ni, HL=3,5-dimethyl-1H-pyrazole-1-carboxamidine) is discussed in the view of their crystal and molecular structure. The compounds contain the same
number and type of hydrogen bonds of the adjacent nitrate ions, only in the opposite orientation. On the basis of their deaquation
pattern such a small difference may be detected, i.e., methods of thermal analysis are sensitive enough to show very small
Authors:V. Leovac, E. Ivegeš, K. Szécsényi, K. Tomor, G. Pokol, and S. Gal
Solvate complexes of UO22+ andN(1), N(4)-bis(salicylidene)-S-methylisothiosemicarbazone, (H2Me-L1), of general formula [UO2(Me-L1)S] (S= H2O, MeOH, EtOH, Py, DMF and DMSO) were synthesized. The methanolic UO22+” adducts of N(1)-benzoylisopropylidene-N(4)-salicylidene-S-alkylisothiosemicarbazone, (H2R-L2,R=Me, Prn) of general formula [UO2(R-L2)· MeOH], were also prepared. Thermal decomposition of the complexes was investigated in air and argon. The complexes decompose
to α-U3O8 in air, while in argon the decomposition is not completed up to 1000 K. The temperature and the mechanism of decomposition
of the complexes are a function of the solvent belonging to the inner coordination sphere.
Authors:I. Ivanović, K. Andjelković, V. M. Leovac, Lj. Klisarov, M. Lazarević, and D. Minić
Several new complexes of dioxomolybdenum(VI) of the general formula [MoO2(L)S], whereL is the dianion of salicylaldehydep-hydroxybenzoylhydrazone andS denotes H2O, MeOH, py, PPh3, DMSO or DMF, were synthesized and characterized by elemental analysis, electronic UV-VIS and IR spectra, thermal analysis, molar conductivity and magnetic susceptibility measurements. Salicylaldehydep-hydroxybenzoylhydrazone participates in the coordination as a tridentate ligand with the ONO set of donor atoms. The complexes contain acis-MoO2 group and are of octahedral geometry. Complexes of the MoO2L type were also prepared by synthesis in CHCl3 solution and by isothermal heating of [MoO2(L)S] complexes. The MoO2L complex synthesized in CHCl3 solution has most probably a pentacoordinated structure while the complex obtained by isothermal heating of [MoO2(L)S] has a polymeric hexacoordinated structure.