Interfacial chemistry behavior of phase transfer catalysis for hydroxide ion initiated reactions

A very simple and novel method is devised to study the mechanism of phase transfer catalysis (PTC) for hydroxide ion initiated reactions, i.e., the mechanism of PTC is illustrated by characterizing interfacial dilational viscoelastic properties of the catalysts and intermediates, which are closely related to the interfacial chemistry behavior of the PTC reaction. Interfacial dilational moduli of tetramethylammonium bromide (TMAB), tetraethylammonium bromide (TEAB), and tetrabutylammonium bromide (TBAB) which are amongst the most common phase transfer catalysts at aqueous-organic solvent interfaces, were investigated by interfacial tension response to sinusoidal area variations. The influences of the reactants, including sodium hydroxide, deoxybenzoin and dimethyl sulfate, on the dilational viscoelastic properties of the catalysts were studied. The results obtained from this study can be used for inferring the mechanism of the PTC reaction. (c) 2007 Elsevier B.V. All rights reserved.