Polar aprotic solvent


A polar aprotic solvent is a solvent that lacks an acidic proton and is polar. Such solvents lack hydroxyl and amine groups. In contrast to protic solvents, these solvents do not serve as proton donors in hydrogen bonding, although they can be proton acceptors. Many solvents, including chlorocarbons and hydrocarbons, are classifiable as aprotic, but polar aprotic solvents are of particular interest for their ability to dissolve salts.[1][2] Methods for purification of common solvents are available[3]

Solvent Chemical formula Boiling point Dielectric constant Density Dipole moment (D) Comment
Polar aprotic solvents
acetone C3H6O 56.05 °C 21.83 0.7845 g/cm3 2.91 reacts with strong acids and bases
acetonitrile CH3CN 81.3 - 82.1 °C 38.3 0.776 g/cm3 3.20 reacts with strong acids and bases
dichloromethane CH2Cl2 39.6 °C 9.08 1.3266 g/cm3 1.6
dimethylformamide (CH3)2NCHO 153 °C 36.7 0.95 g/cm3 3.86 reacts with strong bases
dimethylpropyleneurea (CH3)2C4H6N2O 246.5 °C 36.12 1.064 g/cm3 4.23 high b.p.
dimethylsulfoxide (CH3)2SO 189 °C 46.7 1.1 g/cm3 3.96 reacts with strong bases, difficult to purify
ethyl acetate C4H8O2 77.11°C 6.02 0.902 g/cm3 1.88 reacts with strong bases
hexamethylphosphoric triamide [(CH3)2N]3PO 232.5 °C 29.6 1.03 g/cm3 5.38 high b.p., high toxicity
pyridine C5H5N 115 °C 13.3 0.982 g/cm3 2.22 reacts with protic and Lewis acids
sulfolane C4H8SO2 286 °C ? 1.27 g/cm3 4.8 high b.p.
tetrahydrofuran C4H8O 66 °C 7.6 0.887 g/cm3 1.75 polymerizes in presence of strong protic and Lewis acids


  1. ^ Stoye, Dieter (2000). "Solvents". Ullmann's Encyclopedia of Industrial Chemistry. Weinheim: Wiley-VCH. doi:10.1002/14356007.a24_437.
  2. ^ John R. Rumble (ed.). "Laboratory Solvent Solvents and Other Liquid Reagents". CRC Handbook of Chemistry and Physics, 102nd Edition (Internet Version 2021). Boca Raton, FL, USA: CRC Press/Taylor & Francis.
  3. ^ W. L. F. Armarego (2017). Purification of Laboratory Chemicals, 8th Edition. Elsevier. ISBN 9780128054567.