A new approach to the relationship between bond energy and electronegativity

The familiar equation whereby Pauling related heteronuclear bond energies DA–B to the electronegativity difference Δχ (=∣χA − χB∣) and the homonuclear bond energies DA–A and DB–B has been the subject of critical scrutiny for at least half a century. A modification to this equation that combines the concepts of electronegativity and hardness/softness can be rewritten in terms of two quantities x and y, both having absolute significance. Both homo- and heteronuclear bond energies can be rationalised from these new equations. The quantities x are linearly related to Pauling electronegativities, while y appears to be a measure of an atom’s intrinsic bonding potential, related to size and availability of valence orbitals.

Graphical abstractA modified version of Pauling’s bond energy equation can be derived from intuitive expressions for homopolar and heteropolar bond energies DA–A and DA–B in terms of the quantities x and y, which are related to electronegativity and hardness/softness.Figure optionsDownload full-size imageDownload as PowerPoint slide