Modelling of rare earth complexing with acetylacetone with unsaturated organic acid and possibility of its study by NMR method

Equilibria in the system rare earth-acetylacetone-unsaturated organic acid (acrylic, methacrylic) have been considered. A mathematical model permitting definition of stability constants and limiting chemical shifts of different-ligand complexes of the composition 1:1:1 and 1:2:1 has been plotted. As a result of simulation the conditions for NMR experiment were chosen. The influence of concentration conditions on equilibrium distribution of complexes of different composition has been studied. The ranges of values of stepped stability constants of different-ligand complexes, for which calculation of the values is possible with an error not exceeding 10%, provided the absolute determination error of the chemical shifts observed is 0.1 Hz, have been defined. The results obtained are compared with data of PMR spectra. 9 refs., 4 figs