Rate enhancements in a solid-liquid reaction using PTC, microphase, ultrasound and combinations thereof

A phase transfer catalyst (PTC) provides an elegant and efficient way of effecting reaction between components present in two immiscible phases: liquid-liquid and liquid-solid. Such reactions can also be initiated or enhanced by other strategies, such as use of a microphase or ultrasound. Results are reported in this paper on rates and rate enhancements in a model solid-liquid reaction (synthesis of benzyl sulfide from benzyl chloride and sodium sulfide in a suitable organic solvent) in the presence of PTC, microphase, and ultrasound. The study is then extended to include the effects of combinations of these stragegies. A preliminary kinetic analysis of the results is also attempted. For the system studied it is found that the accelerating effect of PTC is the most profound, while that of microphase or ultrasound is only marginal when they are used individually. On the other hand, the effects of microphase and ultrasound acquire far greater significance in the presence of PTC