| Popis: |
Structure of α-(Dimethylamino)benzyllithium in Solution: Dynamic Equilibrium between an η1 and an η3 Species1 Temperature-dependent 1H- and 13C-NMR-spektroscopic shifts observed in tetrahydrofuran are indicative of an equilibrium between a high-temperature η3 and a low-temperature η1 species. MNDO calculations are in accord with this view, and HOESY experiments proof it, too. The equilibrium is controled by solvation or complexation, low Lewis basicity of the solvent or bidentate ligands favoring the η3, high Lewis basicity or tridentate ligands the η1 species. Equilibrium as well as rate constants have been estimated, and from their temperature dependence the thermodynamics of the equilibrium and the activation barriers were calculated. |
Plný text