Abstract
The electronic structure of borabenzene (C5H5B, known also as borinane, borinine, borine) is studied using modern valence bond theory in its spin-coupled (SC) form. Three different types of SC wave functions-with six active pi orbitals and with four and eight active sigma orbitals-are used to describe the pi system of the molecule and the sigma-bond framework around the boron atom. It is demonstrated that the SC picture of the pi space in borabenzene is very similar to that in benzene: The spins of six distorted nonorthogonal 2p(pi) orbitals are combined in a spin-coupling pattern involving two dominating Kekule-type and three less important Dewar-type Rumer spin functions. This indicates that it is appropriate to consider the pi-electron sextet in borabenzene as aromatic and that the reason for the reactivity of this molecule should lie with its sigma framework. The two SC models of the sigma bonding around B show that the boron-carbon sigma bonds in borabenzene involve orbitals are ''bent'' to the outer side of the six-membered ring. This creates an orbital ''hole'' at the boron, which should represent the preferred attachment site for Lewis acids. (C) 1997 John Wiley & Sons, Inc.
| Original language | English |
|---|---|
| Pages (from-to) | 441-449 |
| Number of pages | 9 |
| Journal | INTERNATIONAL JOURNAL OF QUANTUM CHEMISTRY |
| Volume | 63 |
| Issue number | 2 |
| Publication status | Published - 20 May 1997 |
Keywords
- VALENCE-BOND DESCRIPTION
- MOLECULES
- CYCLOPROPANE
- NITROGEN
- BENZENE