INFLUENCE OF LOCAL STRUCTURAL CORRELATIONS ON FREE-RADICAL REACTIONS IN SUPERCRITICAL FLUIDS - A HIERARCHICAL APPROACH

We present a general methodology that can be used to study the structu ral effects of supercritical solvents on fast reactions. Using a hiera rchy of theoretical, computational, and spectroscopic methods, we inve stigate the effect of local solvent structure on a model free-radical reaction. Our results from theory and experiments indicate the existen ce of locally high solvent densities around reactants at subcritical b ulk densities. By comparing simulations and experiments, we show how t hese local structural correlations enhance the rate constant for Heise nberg spin exchange in supercritical fluids.