Polymeric Nucleophiles and Cosolvents. The Reactivity of Poly(ethylene glycol) and Its Derivatives with Benzyl Bromide under Solvolytic Conditions

摘要

Pseudo first-order rate constants for the solvolytic displacement of benzyl bromide in 100% ethanol and in 80 and 60% aqueous ethanol (v/v) are reported. The effect of adding poly(ethylene glycol)(PEG) and PEG dithiols and diamines to the solvolytic solutions has been studied. Grunwald-Winstein plots and second-order rate constants revealed that the polymeric diamines caused the benzyl bromide to undergo polymer-assisted displacement in all solvent compositions. Since it was noted that the second-order rates increased as the PEG amine molecular weight increased; it appears that the PEG framework may be assisting the reaction.