Kinetic studies by stopped-flow pulse Fourier transform nuclear magnetic resonance

Abstract
An attachment for a commercial pulse Fourier transform nuclear magnetic resonance spectrometer is described, which enables two solutions to be rapidly and efficiently mixed inside a spinning 5 mm diameter NMR tube. Complete high resolution 1H NMR spectra can be obtained with 0.2 s of mixing, and at a repetition rate of ca. 0.6 s per spectrum in favourable cases. The technique is illustrated by rapid reactions involving the base-catalysed hydrogen-deuterium exchange between methanol-d4 and the nitromethane anion ((CH2NO2)-), and by the chlorination of tris-(2,4-pentanedione)cobalt(III) ((Co(acac)3)) by N-chlorosuccinimide.