SF6 has sulfur at the center with six S–F single bonds and no lone pairs on sulfur. The six bonding domains point toward the vertices of an octahedron.
Sulfur supplies six valence electrons and six fluorines supply forty-two, giving forty-eight total. Six single bonds consume twelve electrons, and the remaining thirty-six complete the fluorine octets. Sulfur is surrounded by twelve bonding electrons in the expanded-valence Lewis model.
How to draw the SF6 Lewis structure
Count 48 valence electrons.
Add 6 from sulfur and 7 from each fluorine.
Place sulfur in the center.
Fluorine is terminal and normally forms one bond.
Draw six S–F single bonds.
The six bonds use 12 electrons.
Complete all fluorine octets.
Place three lone pairs on each F, using the remaining 36 electrons.
Check charges and domains.
Formal charges are zero and sulfur has six bonding domains.
Expanded valence shell
The standard Lewis representation places twelve electrons around sulfur. Introductory chemistry describes this as an expanded octet; more advanced molecular-orbital descriptions avoid treating the bonds as six localized two-center bonds in a literal way.
Geometry and polarity
Six equivalent electron domains produce octahedral geometry. Because all six S–F bonds are arranged symmetrically, their bond dipoles cancel and SF6 is nonpolar overall.
Common mistakes
Drawing only four or five fluorine atoms around sulfur.
Adding a lone pair to sulfur after all 48 electrons are assigned.
Calling the geometry trigonal bipyramidal; that geometry has five domains, not six.
Forgetting the three lone pairs on each fluorine.
Frequently asked questions
How many lone pairs are on sulfur in SF6?
There are no lone pairs on sulfur in the standard SF6 Lewis structure.
Is SF6 polar?
No. The octahedral symmetry cancels the six S–F bond dipoles.
What hybridization is commonly assigned to sulfur?
Traditional introductory texts use sp³d², though modern bonding explanations are more nuanced.