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	low boiling point
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 boiling point
dimethyl sulfoxide	(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
hexamethylphosphoramide	[(CH3)2N]3PO	232.5 °C	29.6	1.03 g/cm3	5.38	high boiling point, 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 boiling point
tetrahydrofuran	C4H8O	66 °C	7.6	0.887 g/cm3	1.75	polymerizes in presence of strong protic and Lewis acids

References

1. Stoye, Dieter (2000). "Solvents". Ullmann's Encyclopedia of Industrial Chemistry. Weinheim: Wiley-VCH. doi:10.1002/14356007.a24_437. ISBN 3527306730.
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.