It is also extensively used as an extractant in biochemistry and cell biology.
DMSO is frequently used as a solvent for chemical reactions involving salts, most notably Finkelstein reactions and other nucleophilic substitutions. Applications Solvent ĭistillation of DMSO requires a partial vacuum to achieve a lower boiling point.ĭMSO is a polar aprotic solvent and is less toxic than other members of this class, such as dimethylformamide, dimethylacetamide, N-methyl-2-pyrrolidone, and hexamethylphosphoramide (HMPA).
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The relative donor strength of DMSO toward a series of acids, versus other Lewis bases, can be illustrated by C-B plots. The donor properties are discussed in the ECW model. In carbon tetrachloride solutions DMSO functions as a Lewis base with a variety of Lewis acids such as I 2, phenols, trimethyltin chloride, metalloporphyrins, and the dimer Rh 2Cl 2(CO) 4. In general, the oxygen-bonded mode is more common. The fourth DMSO is bonded through oxygen. In this complex, three DMSO ligands are bonded to ruthenium through sulfur. Illustrative is the complex dichlorotetrakis(dimethyl sulfoxide)ruthenium(II) (RuCl 2(dmso) 4). Related to its ability to dissolve many salts, DMSO is a common ligand in coordination chemistry. These all involve formation of an intermediate sulfonium species (R 2S +X where X is a heteroatom). The Kornblum oxidation is conceptually similar. It forms the basis of several selective sulfonium-based oxidation reactions, including the Pfitzner–Moffatt oxidation, Corey–Kim oxidation, and Swern oxidation. In organic synthesis, DMSO is used as a mild oxidant. It is a base, e.g., for the deprotonation of ketones to form sodium enolates, phosphonium salts to form Wittig reagents, and formamidinium salts to form diaminocarbenes. The sodium derivative of DMSO formed in this way is referred to as dimsyl sodium. Stabilization of the resultant carbanion is provided by the S(O)R group. For this reason, the basicities of many weakly basic organic compounds have been examined in this solvent.ĭeprotonation of DMSO requires strong bases like lithium diisopropylamide and sodium hydride.
The methyl groups of DMSO are only weakly acidic, with a p K a = 35. I + NaH → (CH 3) 2S(CH 2)O + NaI + H 2 Acidity This salt can be deprotonated with sodium hydride to form the sulfur ylide: With methyl iodide it forms trimethylsulfoxonium iodide, I: The sulfur center in DMSO is nucleophilic toward soft electrophiles and the oxygen is nucleophilic toward hard electrophiles. Dimethyl sulfoxide is produced industrially from dimethyl sulfide, a by-product of the Kraft process, by oxidation with oxygen or nitrogen dioxide.
It has a trigonal pyramidal molecular geometry consistent with other three-coordinate S(IV) compounds, with a nonbonded electron pair on the approximately tetrahedral sulfur atom.ĭimethyl sulfoxide was first synthesized in 1866 by the Russian scientist Alexander Zaytsev, who reported his findings in 1867. In terms of chemical structure, the molecule has idealized C s symmetry. DMSO has the unusual property that many individuals perceive a garlic-like taste in the mouth after DMSO makes contact with their skin. It is an important polar aprotic solvent that dissolves both polar and nonpolar compounds and is miscible in a wide range of organic solvents as well as water. This colorless liquid is the sulfoxide most widely used commercially. Dimethyl sulfoxide ( DMSO) is an organosulfur compound with the formula ( CH 3) 2 S O.
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