Study of thermodynamic and kinetic properties of metal complexes with modified tetraazamacrocyclic
                                              ligands


                                Radek Ševčík^ 1, Přemysl Lubal^ 1,2

^1  Masaryk University, Department of Chemistry, Kotlářská 2, 611 37 Brno, Czech Republic

^2 Central European Institute of Technology (CEITEC), Masaryk University, Kamenice 5,

  625 00 Brno, Czech Republic


Polyazamacrocyclic ligands with coordinating pendant arms form stable complexes with wide scale of
metal ions. Properties of these complexes predict them to apply in medicine. For any biomedical
applications, these metal complexes would exhibit a high thermodynamic stability under
physiological conditions because of toxicity of used metal ions, competitive reaction with
body-occurred ligands e.g. amino acids, phosphates, peptides and metal ions like Ca(II), Zn(II) and
others. However, the thermodynamic stability is not only one request; it is also very important
that metal complexes must have a sufficient kinetic inertness to prevent their decomposition in the
human body. Therefore, knowledge of their thermodynamic as well as kinetic properties (e.g.
dissociation rate constants for an estimation of kinetic inertness) is important to evaluate their
use in these applications.

In this work, the formation and acid-assisted dissociation kinetics of Cu(II) and some Ln(III)
complexes with macrocyclic ligands of cyclen type (cyclen – 1,4,7,10–tetraazacyclododecane) having
acetate and phosphorus acid pendant arms were studied using molecular absorption spectroscopy,
luminescence spectroscopy in steady-state and time-resolved mode.


Acknowledgements:

This work was done in the framework of EU CM1006 program. We thank to Ministry of Education of the
Czech Republic (grants ME09065, CEITEC CZ.1.05/1.1.0/02.0068) and Grant Agency of the Czech
Republic (13-08336S) for financial support.