Journal of the Serbian Chemical Society 2016 Volume 81, Issue 8, Pages: 897-905
https://doi.org/10.2298/JSC160320059M
Full text ( 2124 KB)
Cytotoxic Pt(IV) and Ru(II) complexes containing a biologically relevant edda-type ligand: A comparative study of their thermal properties
Mihajlović-Lalić Ljiljana E. (Innovation Center of the Faculty of Chemistry, Belgrade)
Damjanović Ljiljana (Faculty of Physical Chemistry, Belgrade)
Šumar-Ristović Maja (Faculty of Chemistry, Belgrade)
Savić Aleksandar (Faculty of Chemistry, Belgrade)
Sabo Tibor J. (Faculty of Chemistry, Belgrade)
Dondur Vera (Faculty of Physical Chemistry, Belgrade)
Grgurić-Šipka Sanja (Faculty of Physical Chemistry, Belgrade)
The thermal behaviour of a Pt(IV) and a Ru(II) complex coordinated to
O,O'-di-n-butyl-(S,S)-ethylenediamine-N,N'-di-2-(3-cyclohexyl)propanoate has
been investigated using thermogravimetry (TG) and differential scanning
calorimetry (DSC). The study included investigation of the thermal
decomposition of these complexes in the temperature range of 30 to 590°C and
evaluation of activation energy for the first decomposition steps. For both
metal complexes, broad DSC peaks indicated complex thermal transformation
processes. The two-step decomposition of the Pt(IV) complex started at 175
and ended at about 418°C, leaving elemental platinum as a final residue. On
the other hand, the Ru(II) analogue decomposed in three stages. Thermal
degradation was evident beginning at 144°C and suggested the decomposition of
a coordinated ligand as dominant process. For this complex, the proposed
final residue was RuO2. Kinetic parameters for the first decomposition step
were obtained by means of multi-heating rates method, in this case the
Kissinger-Akahira-Sunose (KAS) method. The mean activation energy calculated
for 0.2 < α < 0.8 were 122.0 kJ mol−1 for the Pt(IV) and 118.9 kJ mol−1 for
the Ru(II) complex and decreased constantly, characteristic of a multi-step
process.
Keywords: platinum (IV) complex, ruthenium (II) complex, antitumor activity, activation energy, TG−DSC
Projekat Ministarstva nauke Republike Srbije, br. 172035, 172055 i
br. 172018