aprotik

Aprotik is the Indonesian-language term foraproctic, used in chemistry to describe solvents and media that do not donate protons (H+) in acid–base reactions. The corresponding English term is aprotic, and the concept is widely used in chemical literature to distinguish solvents that cannot act as hydrogen-bond donors from those that can.

Aprotic solvents lack O–H and N–H bonds, so they cannot donate protons under typical reaction conditions. They may be polar or nonpolar and often stabilize ions through dipole interactions, coordination to solutes, or solvation without hydrogen bonding to solutes. They generally exhibit low acidic character and do not participate in proton transfer in standard organic reactions.

Common examples include dimethyl sulfoxide (DMSO), acetonitrile, acetone, dimethylformamide (DMF), tetrahydrofuran (THF), diethyl ether, and dichloromethane. Some hydrocarbons like toluene are also considered aprotic, though they are nonpolar and have limited solvation power for ionic species compared with more polar aprotic solvents.

Applications of aprotic solvents are widespread in organic synthesis, where the absence of proton donation helps avoid neutralizing reactive bases or nucleophiles. They are especially important in reactions involving strong bases or highly reactive organometallic reagents (for example, Grignard reagents and organolithiums) and in SN2 processes where hydrogen-bonding solvents can hinder nucleophilicity. Dry or oxygen-free conditions are often required to maintain solvent suitability and reagent stability.

See also: protic solvent, solvent (chemistry), Grignard reagent.