Dimethyl sulfoxide is an important polar aprotic solvent that can dissolve both polar and nonpolar compounds and is miscible in a wide range of organic solvents as well as water. Because it penetrates the skin very readily, it is sometimes used as a vehicle for topical application of pharmaceuticals.

Draw the structure of dimethyl sulfoxide. Include any nonbonding electrons on sulfur, and minimize formal charges by allowing sulfur to expand its octet.