Evidence for a simple scaling law relating neutral and cation diatomic bond energies

摘要

In the past, much chemical research has been motivated and directed by the discovery of empirical scaling laws. Today, such laws still have import, most notably as guideposts for developing better and more efficient methods of approximation in theoretical chemistry. In the course of a project examining neutral and singly-ionized cation bond energies, we have found evidence for a simple scaling law relating diatomic cation and neutral bond strengths: the loss of a valence electron from a 'generic' diatomic has little effect on the bond energy (i.e. D-e(AB(+)) congruent to 1.1De(AB)). Further, we find that this result varies only marginally over the population of all covalent bonds, including both singly and multiply bonded diatomics. Here, we present the evidence for this scaling law, and explore its qualitative implications for molecular structure. (c) 2005 Elsevier B.V. All rights reserved.