Protonation of alcohols by hydrogen bromide in dibromodifluoromethane; rates of proton exchange and alcohol basicity
Abstract
Alcohols are protonated by HBr in CBr2F2, and at low temperatures separate 1H n.m.r. signals for HBr and ROH2+ are observed. Line-shape analysis of the n.m.r. spectra at different temperatures has been used to determine the rates of proton exchange between HBr and the protonated alcohol. The rates are well correlated with the Taft σ1 parameter for the alcohols and provide an order of basicities for these weak bases in CBr2F2.