Hydrogen bonding and proton transfer in hydrido-bis-phenolate complexes in acetone
Abstract
The homoconjugation, (ArO)2H–, and heteroconjugation, Ar′O–⋯HOAr, (where Ar is aromatic) with proton transfer have been determined in acetone at 298 K. Tetra-alkylammonium phenolates were titrated with a variety of phenols to given homocomplexes and heterocomplexes. Potentiometric data give the overall equilibria constants, K0, proton-transfer constants, KPT and formation constants, Kf. Two types of heterocomplexes were studied. When ArO– is a weaker base than Ar′O–, the complexation occurs without proton transfer, as confirmed by the low K0 values for the reaction. The overall equilibrium constants, K0, are large when ArO– is a stronger base than Ar′O–, as both the equilibrium proton-transfer constant (KPT) and equilibrium formation constant (Kf) of the hydrogen bond are included in the measurement of K0=KfKPT.