Dimethyl sulfoxide (DMSO) is a sulfur-containing organic compound with the molecular formula C2H6OS. At room temperature, it is a colorless, odorless transparent liquid, a hygroscopic and flammable liquid. It is highly polar, has a high boiling point, good thermal stability, is aprotic, and miscible with water. It can dissolve in most organic substances such as ethanol, propanol, benzene, and chloroform, earning it the title "universal solvent." When heated in the presence of acid, it produces small amounts of compounds such as methyl mercaptan, formaldehyde, dimethyl sulfide, and methanesulfonic acid.

1. Dimethyl sulfoxide can be reduced to form dimethyl sulfide. It oxidizes to dimethyl sulfone when exposed to strong oxidizing agents;
2. When dimethyl sulfoxide comes into contact with acyl chlorides such as cyanuric chloride, benzoyl chloride, acetyl chloride, benzenesulfonyl chloride, thionyl chloride, sulfuryl chloride, and phosphorus trichloride, it undergoes intense exothermic decomposition reactions. It combines with nitric acid to form (CH3)2SO·HNO3. It can be regenerated by reacting with barium carbonate. When reacted with concentrated hydriodic acid, it forms dimethyl sulfonium compounds.
3. Dimethyl sulfoxide is hygroscopic and requires drying before use.

DMSO, or dimethyl sulfoxide, has a wide range of applications. It is used as a solvent for acetylene, aromatic hydrocarbons, sulfur dioxide, and other gases, as well as a solvent for acrylic fiber spinning. It is an extremely important aprotic polar solvent that is soluble in both water and organic solvents. It has strong skin permeability, aiding in the penetration of drugs into the human body. It can also serve as an additive in pesticides and is a very important chemical reagent.
DMSO is also a cryoprotectant that can lower the freezing point of cells, reduce ice crystal formation, mitigate free radical damage to cells, and alter the permeability of biological membranes to electrolytes, drugs, toxins, and metabolites.
DMSO has solubility and permeability for many drugs. It also possesses anti-inflammatory, analgesic, blood circulation-promoting, wound-healing, diuretic, and sedative properties. It can enhance drug absorption and efficacy. When drugs are dissolved in DMSO, they can penetrate the body through skin application without the need for oral or injection administration, opening up new routes for drug delivery. More importantly, it increases local drug concentration in the affected area while reducing drug-related harm to other organs.
DMSO serves as a solvent, penetrant, and synergist for pesticides and fertilizers. Antibiotics dissolved in DMSO can treat fruit tree canker, while insecticides dissolved in DMSO can kill borers in trees and fruits. Spraying a 0.5% solution during the soybean flowering period can increase yield by 10% to 15%. Adding 0.5% DMSO to various fertilizer solutions allows for foliar fertilization.
DMSO is used in farad-level, ultra-large capacity capacitors. It is widely used in the cleaning of electronic components and integrated circuits due to its ability to remove organic, inorganic, and polymeric contaminants in one step. It is non-toxic, odorless, and easily recyclable.
In chemical reactions, DMSO acts as both a reaction solvent and a reagent. Certain difficult-to-achieve reactions can proceed smoothly in DMSO. It can accelerate and catalyze specific chemical reactions, improve yields, and alter product properties.