Electronegativity partial charge model

The partial charges model [2], based on Sanderson s principle [3] of electronegativity equalization jn a compound, does not allow an absolutely accurate estimation of the charges, and in this respect has limitations similar to other methods. However, it is interesting to study its application to some problems of... 

The partial charges model, is a simple and convenient method for the broad prediction of the behavior of elements in solution. Electronegativity, i.e. the electronic chemical potential, seems to be an adequate and useful concept in the understanding of the direction of electron transfers between atoms. Therefore, it is a useful concept in predicting the evolution of a chemical system, since the principle of electronegativity equalization can broadly characterize an equilibrium situation. 

Finally, as a further contribution to understanding of bonding in hypervalent molecules. Sun has offered an alternative model of bonding in hexacoordinated molecules, eg SFg and PFej", which does not involve d-orbital participation but employs the concept of the three center, four electron bond. The model was supported by the use of a partial charge analysis using Allen s electronegativity approach. ... 

In contrast to the claim (10) that the ECW model "disguises the relationship between reactivity and periodic elemental properties", elementary application of frontier molecular orbital theory (H) can be used to understand the trends. Using qualitative trends in ionization energies, inductive effects, electronegativities and partial charge/size ratios, one can estimate trends in the HOMO-LUMO separation of the donor and acceptor. Increasing the separation decreases the covalent and increases the electrostatic nature of the interaction. Decreasing the separation has the opposite effect. Trends in the reported acid and base parameters as well as in the Ey E0 and C C0 products can be understood in this way. 

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