Surfactant-Dependent Partitioning of Organics in Aqueous-Organic Reaction Systems.

A fluorescence lifetime imaging microscopy (FLIM) technique characterizes surfactant-dependent partitioning of organics in a system that mimics a Negishi-like cross-coupling reaction in water, under synthetic concentrations, with emulsion droplets. Experimental partitioning data were not predictable from simple hydrophilic-lipophilic balances. The ionic surfactant cetrimonium chloride suppressed the reactivity of the metallic zinc surface, presumably through competitive chloride binding and concurrent cetrimonium coating, a finding that may contribute to the reduced performance of ionic surfactants in the bench-scale coupling reaction.