Dimethyl Sulfoxide overview
The stored Lewis connectivity is (CH₃)₂S=O ↔ (CH₃)₂S⁺—O⁻. DMSO is commonly drawn with S=O, but a charge-separated S⁺–O⁻ contributor is essential to understanding its polarized bond.
How to draw C₂H₆OS
- Count 26 valence electrons. Include charge adjustments before drawing.
- Use the reviewed connectivity (CH₃)₂S=O ↔ (CH₃)₂S⁺—O⁻. Do not infer a different isomer from the formula alone.
- Place the required single, double or multiple bonds. Keep a running electron total.
- Complete terminal valence shells and add lone pairs or formal charges. DMSO is commonly drawn with S=O, but a charge-separated S⁺–O⁻ contributor is essential to understanding its polarized bond.
- Verify the total electron count and geometry. The reviewed geometry is Trigonal pyramidal around sulfur.
Why this example matters
DMSO is commonly drawn with S=O, but a charge-separated S⁺–O⁻ contributor is essential to understanding its polarized bond.
Scope and model limits
No single Lewis drawing completely describes the S–O bond. The page presents the two common bookkeeping forms and their limits.
Common mistakes
- Using 20 instead of 26 valence electrons
- Calling sulfur simply bent with only two domains
- Ignoring the charge-separated contributor
Related reviewed guides
Last reviewed: 2026-07-16. Educational reference only; verify graded work with course materials.