Oxygen difluoride Lewis structure
The oxygen difluoride Lewis structure corresponds to the molecular formula OF2 with oxygen as the central atom bonded to two fluorine atoms. Single bonds satisfy the typical bonding preferences of fluorine, and oxygen completes an octet by retaining two lone pairs.
Compact description
Connectivity: F–O–F. Lone pairs: oxygen has 2 lone pairs; each fluorine has 3 lone pairs. Formal charges: all atoms have formal charge 0.
Valence-electron accounting
Valence electrons come from the periodic table group numbers: oxygen contributes 6 and each fluorine contributes 7. The total is
\[ 6 \;+\; 2 \times 7 \;=\; 20 \text{ valence electrons.} \]
| Component | Electron count | Interpretation |
|---|---|---|
| Total valence electrons | \(20\) | Electrons available for bonds and lone pairs |
| Two single bonds (O–F and O–F) | \(2 \times 2 = 4\) | Two bonding pairs |
| Lone pairs on two fluorine atoms | \(2 \times 6 = 12\) | Three lone pairs per fluorine |
| Remaining for oxygen lone pairs | \(20 - 4 - 12 = 4\) | Two lone pairs on oxygen |
Octets and electron-pair geometry
Each fluorine reaches an octet through one single bond plus three lone pairs. Oxygen reaches an octet through two single bonds plus two lone pairs. The electron-domain arrangement around oxygen is tetrahedral (four electron domains), while the molecular shape is bent because two domains are lone pairs.
Formal charge check
Formal charge is evaluated by
\[ \text{FC} \;=\; V \;-\; \left(N \;+\; \frac{B}{2}\right) \]
For oxygen in OF2, \(V=6\), \(N=4\) (two lone pairs), and \(B=4\) (two single bonds). This gives \(\text{FC}=6-(4+2)=0\). For each fluorine, \(V=7\), \(N=6\), and \(B=2\), giving \(\text{FC}=7-(6+1)=0\). Zero formal charges align with the dominant Lewis representation.
Visualization
Molecular polarity and oxidation state note
Fluorine is more electronegative than oxygen, so each O–F bond dipole points toward fluorine. The bent geometry prevents complete cancellation, so oxygen difluoride is polar. The oxidation-state assignment places oxygen at \(+2\) and each fluorine at \(-1\), an unusual case that remains consistent with fluorine’s strong tendency to form \(-1\) in compounds.
Common pitfalls
- The central atom assignment places oxygen in the middle because fluorine typically forms only one bond in Lewis structures.
- Double bonds are not favored for OF2; single bonds with full octets and zero formal charges dominate.
- The electron-domain arrangement is tetrahedral around oxygen, while the molecular shape is bent due to two lone pairs.