Dynamic nuclear magnetic resonance measurements of the basicity of weak organic bases in super-acid media

Abstract

Solutions of a number of weak organic bases (such as nitro-compounds, ketones, aldehydes, ethers, and alcohols) in mixtures of fluorosulphuric acid and antimony pentafluoride have been examined by dynamic n.m.r. measurements. The rate of proton loss from the conjugate acids of these bases affords an inverse measure of their relative basic strengths, and amplifies the acidity measurements on the solvent system. N.m.r. spectral parameters are listed for the protonated bases.