Abstract
Modern valence bond theory, in its spin-coupled form, is used to investigate:the bonding in sulfuryl fluoride, SO2F2, and in the thionyl fluorides, SOF2 and SOF4. Analogous calculations are also carried out for SO2, SO3 and SF4, to enable various comparisons to be made. We find that the sulfur atoms in these systems utilize all six valence electrons in two-centre two-electron polar covalent bonds and in angularly split lone-pair-like orbitals. Although based on just a single orbital configuration, the spin-coupled wavefunction provides a significant energy improvement over the corresponding restricted Hartree-Fock calculation. The spin-coupled description of the S=O and S-F bonding, and of the non-bonding electrons on sulfur, turns out to be highly transferable. We find that the S-O pi bonds are significantly more polar than the S-O a bonds. We find no evidence to support notions of p(z)-d(pi) back-donation from oxygen to sulfur. We examine also the 'equivalent' or 'bent-bond' model of the SO units in the thionyl fluorides.
| Original language | English |
|---|---|
| Pages (from-to) | 2247-2254 |
| Number of pages | 8 |
| Journal | JOURNAL OF THE CHEMICAL SOCIETY-FARADAY TRANSACTIONS |
| Volume | 93 |
| Issue number | 13 |
| Publication status | Published - 7 Jul 1997 |
Keywords
- MAIN GROUP ELEMENTS
- D-ORBITAL PARTICIPATION
- 2ND ROW ATOMS
- MOLECULAR CALCULATIONS
- ELECTRON-DIFFRACTION
- WAVE-FUNCTIONS
- VALENCE BONDS
- BASIS SETS
- ABINITIO