The Application of the Hammett Equation with the Constants σph in the Chemistry of Organophosphorus Compounds

The review deals with the application of the Hammett equation to organophosphorus reactions and equilibria using the constants σ^ph. As far as possible a complete list of the constants σ^ph is given. Analysis of the application of the constants σ^ph shows that linear correlations between the rate and equilibrium constants for organophosphorus reactions are usually obtained when the phosphorus atom is not a reaction centre.
For reactions involving phosphorus directly, linear correlations are achieved with the aid of the inductive (σ^ph_I) and resonance (σ^ph_R) constants, namely: Σ(σ^ph_I+ασ^ph_R). A method of calculation of the constants σ^ph_I and σ^ph_R is described and as far as possible a complete list of these constants is given for various groups attached to the phosphorus atom. It has been demonstrated on 124 reaction series as examples the function Σ(σ^ph_I+ασ^ph_R) makes it possible to construct a universal system for the σρ analysis of reactions, equilibria, and certain physical constants in the chemistry of organophosphorus compounds on the basis of the equation lgK = lgK⁰+ρΣ(σ^ph_I+ασ^ph_R) with high correlation coefficients. The relation between the constants α and ρ on the one hand and the type of reaction and its mechanism on the other is discussed.
The bibliography includes 117 references.