The Concept of Electronegativity. Conclusions and Prospects

The principal methods for the determination of the electronegativity (EO) of the elements and radicals are examined – thermochemical, structural, spectroscopic, quantum-chemical, and a method based on ionisation potential. Particular attention is drawn to the necessity of taking into account the characteristic features of the chemical bond – its multiplicity and degree of hybridisation. The problems of the dimensions of the electronegativity of the elements are discussed. A compilation of the recommended electronegativities of atoms, radicals, and ions is given.
The principal applications of the concept of electronegativity are discussed: the determination of the atomic charges in molecules and crystals (good agreement between experimental and theoretical values is demonstrated); an estimate of the multiplicity of chemical bonds in inorganic ions and compounds, which agrees with the determination from the geometrical or spectroscopic characteristics of these substances; the principal physicochemical properties and the behaviour of inorganic substances as a function of the ionic character of their bonds and the difference between the electronegativities of the constituent atoms have been examined (semiconductor and molecular-physical characteristics, acid–base relations, specific features of the transeffect of atoms in the inner sphere of platinum compounds, the possibility of the synthesis of new inorganic substances). The controversial questions of the nature and limits of applicability of the concept of electronegativity in general chemistry are briefly discussed.