Toroid NMR probes for the in situ examination of homogeneous cobalt hydroformylation catalysts at high pressures and temperatures

Toroid NMR probes can be routinely operated at 300 atm and up to 250 degree s C. Such operating conditions make these probes well suited for the in sit u examination of catalytic industrial processes. These probes have been emp loyed to examine phosphine substituted (Shell-type) and unsubstituted cobal t carbonyl oxo catalysts under catalytic and non-catalytic conditions in a variety of solvents. The solvents include cyclohexane, benzene, dioxane, 2- methylpropanol, supercritical carbon dioxide (scCO(2)), and scCO(2)/toluene mixtures. The high-pressure/high-temperature probes allowed the observatio n of precatalytic equilibria under high carbon monoxide pressures in the pr esence and absence of hydrogen and/or free phosphine. (C) 1999 Elsevier Sci ence B.V. All rights reserved.