2008 – Roald Hoffmann
All The Ways to Have A Bond
Any rigorous definition of a chemical bond is bound to be impoverishing, leaving one with the comfortable feeling "yes (no), I have (do not have) a bond," but little else. And yet the concept of a chemical bond, so essential to chemistry, and with a venerable history, has life, generating controversy and incredible interest. Even if we can't reduce it to physics. I will discuss some of the common criteria: length, energy, force constants, magnetism, energy splittings and other spectroscopy criteria, bond orders, population analyses, and bond critical points. My advice is likely to be: Push the concept to its limits, accept that (at the limits) a bond will be a bond by some criteria, maybe not others, respect chemical traditions, have fun with the richness of something that cannot be defined clearly, and spare us the hype.
Dr. Hoffmann decided to change the subject of his talk and in stead talk about Mr. and Mrs. Lavoisier (amongst others).