Modern valence bond theory has been used to enforce sp3d2 hybridization in SF6. Alternative bonding schemes with no d-orbital contribution are presented and yield lower total energies in agreement with previous studies discounting the role of sp3d2 hybrid orbitals. Therefore, the use of d-orbital hybridization to describe hypervalent molecules should be removed from the general chemistry curriculum. Instead, bonding in SF6 can serve as a good example of the role of theory in chemistry, nicely illustrating that no theory provides all the right answers all the time. More detailed valence bond and molecular orbital descriptions can be reserved for advanced courses. A more in depth look at SF6 highlights the similarities between molecular orbital and valence bond theories and the importance of resonance mixing of covalent and ionic valence bond structures as well as fragment orbital mixing in order to make delocalized molecular orbitals.
More Information
Citation
Galbraith, John Morrison. J. Chem. Educ.2007, 84, 783.
Keywords
Computational Chemistry; First-Year Undergraduate / General; Inorganic Chemistry; Misconceptions / Discrepant Events; MO Theory; Physical Chemistry; Upper-Division Undergraduate; Valence Bond Theory
Our Secondary School editors work hard to distill all the JCE materials to produce a fraction of particular interest to high school teachers. We call it CLIC.
In recent years we have worked hard to better match our advertisers with our readers. When shopping for chemistry education materials, visit our advertisers' WWW sites first.
Take JCE along on your outreach missions. Copies of the Journal, guest access to JCE Online, our publications catalog, and more are available for your participants.