A New Apparatus for the Convenient Measurement of NMR Spectra in High-Pressure Liquids

A novel design is presented for a high-pressure NMR cell using fused silica capillary tubing. The capillary tubing is bent to form multiple loops for use in a 5 mm NMR tube in a conventional solution NMR probe. The NMR cell design eliminates explosion hazards at high pressures and makes possible simple sample loading and observation of reaction mixtures at variable pressures (up to 4 kbar) and temperatures. A chamber for the mixing and flow introduction of reaction mixtures is provided. Examples of application of the cell for 1H, 129Xe, and 19F studies of supercritical fluids, near-critical liquids, and high-pressure organometallic reactions are presented.