Sulfur hexafluoride Lewis structure represents SF6 with sulfur as the central atom and six equivalent S–F single bonds. Each fluorine completes an octet with three lone pairs, while sulfur shows an expanded octet consistent with an octahedral electron-domain arrangement.
Valence-electron accounting
Total valence electrons come from sulfur (group 16) and six fluorine atoms (group 17).
\[ N_\text{valence} = 6 + 6 \cdot 7 = 48 \]
Bonding framework and lone pairs
Six single S–F bonds use twelve electrons.
\[ N_\text{bonding} = 6 \cdot 2 = 12 \]
Remaining electrons appear as lone pairs on fluorine.
\[ N_\text{nonbonding} = 48 - 12 = 36 \]
Three lone pairs per fluorine correspond to six nonbonding electrons per fluorine.
\[ 6\ \text{F atoms} \cdot 6\ \text{nonbonding electrons per F} = 36 \]
Formal-charge consistency
Formal charge uses valence electrons \(V\), nonbonding electrons \(N\), and bonding electrons \(B\).
\[ \mathrm{FC} = V - \left(N + \frac{B}{2}\right) \]
Sulfur has six single bonds and no lone pairs.
\[ \mathrm{FC}(S) = 6 - \left(0 + \frac{12}{2}\right) = 0 \]
Each fluorine has three lone pairs and one single bond.
\[ \mathrm{FC}(F) = 7 - \left(6 + \frac{2}{2}\right) = 0 \]
| Atom | \(V\) | \(N\) | \(B\) | \(\mathrm{FC}\) |
|---|---|---|---|---|
| S | 6 | 0 | 12 | \(0\) |
| F (each) | 7 | 6 | 2 | \(0\) |
Lewis structure diagram (Correct Lone-Pair Placement)
Geometry associated with the structure
Six bonding regions and zero lone pairs on sulfur correspond to an AX6 VSEPR pattern. Electron-domain geometry and molecular geometry are octahedral, with ideal bond angles of \(90^\circ\) and \(180^\circ\).
Common sources of mismatch
Valence-electron totals that do not reach \(48\) for SF6.
Lone pairs placed on sulfur despite the electron accounting assigning all remaining electrons to fluorine.
Multiple bonds drawn to fluorine, typically producing inconsistent formal-charge patterns in a basic Lewis-structure treatment.