Coordination Mode and Kinetic Behavior of the Tetracarbonatozirconate Ion

The behavior of [Zr(CO₃)₄]⁴⁻ complex in solution is studied by determining the coordination mode of the carbonato ligands and the kinetic law of the equilibrium between free and complexed carbonates. Raman polarization and dynamic ¹³C-NMR experiments show that complexed carbonates are bidentate. Magnetization-transfer experiments give the values of pseudo-first-order rate constants for the equilibrium with no net chemical transformation. The treatment of these parameters suggests a second-order rate law. As no solvent effect is noticed, an associative mechanism of ligand exchange is proposed.