Substrate reactivity, linear correlations

On the Theory of Heterogeneous Catalysis Jcro Horiuti and Takashi Nakamura Linear Correlations of Substrate Reactivity in Heterogeneous Catalytic Reactions M- Kraus... 

Linear Correlations of Substrate Reactivity in Heterogeneous Catalytic Reactions... 

A major method of modeling the effect of structural variation on chemical reactivity, physical properties or biological activity of a set of substrates is the use of correlation analysis. In this method it is assumed that the effect of structural variation of a substituent X upon some chemical, physical or biological property of interest is a linear function of parameters which constitute a measure of electrical, steric, and transport effects. 

The oxidation of meta- and para-substituted anilines with imidazolium fluorochro-mate (IFC)18 and nicotinium dichromate (NDC),19 in several organic solvents, in the presence of p-toluenesulfonic acid (TsOH) is first order in the oxidant and TsOH and is zero order with respect to substrate. A correlation of rate data in different solvents with Kamlet-Taft solvatochromic parameters suggests that the specific solute-solvent interactions play a major role in governing the reactivity, and the observed solvent effects have been explained on the basis of solute-solvent complexation. The oxidation rates with NDC exhibited negative reaction constants, while the oxidation with IFC did not correlate well with any linear free energy relationships. 

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