Thermodynamic and kinetic study of Copper(II) Complexes with N-methylene(phenylphosphinic) Derivatives of Cyclen and Cyclam

Investor logo

Warning

This publication doesn't include Faculty of Arts. It includes Faculty of Science. Official publication website can be found on muni.cz.
Authors

LUBAL Přemysl KÝVALA Mojmír HERMANN Petr HOLUBOVÁ Jana ROHOVEC Jan HAVEL Josef LUKEŠ Ivan

Year of publication 2001
Type Article in Periodical
Magazine / Source Polyhedron
MU Faculty or unit

Faculty of Science

Citation
Field Inorganic chemistry
Keywords polyazamacrocycles phosphinic acids; cyclen and cyclam derivatives; copper(II) complexes; potentiometry; kinetics; stability constants
Description Equilibria of Cu(II) with newly synthetised ligands H4L1 and H4L2 were investigated by the glass electrode potentiometry at 25 degrees of Celsius and I = 0.1 M KNO3. A simple chemical model with metal:ligand molar ratio 1:1 was found in the systems. Presence of main species , CuL1 (log Beta = 20.37(4)) and CuL2 (log Beta = 17.19(2)) was also confirmed by MALDI-TOF/MS. The dissociation kinetics of the complexes was followed by spectrophotometry and mechanism of the dissociation was proposed. Activation parameters (activation enthalpy and entropy) of the dissociation were estimated. For Cu(II)-H4L1 system, the complex dissociation starts after protonization of phosphinic pendant arms and its mechasnism is similar to the decomplexation of [Cu(cyclen)]2+. The complex with H4L2 is kinetically much less stable and the proton transfer from phosphinic pendant arm to the azacycle plays a significant role in the reaction mechanism.
Related projects:

You are running an old browser version. We recommend updating your browser to its latest version.