Tables for Chemistry

Solvent polarity acc. Dimroth and Reichardt

Dimroth and Reichardt determined the wavenumber of the absorption maximum for a betain dye as a measure of the ionizing power of solvents. It is converted to kcal/mol (2.86x104λ-1) to give ET.
Normalizing to a scale from TMS (0) to water (1) gives ETN.
See e.g. IUPAC Gold Book.

Dimroth's ET values
NameCAS nrETETN
2-propanone67-64-142.20.35
4-methyl-2-oxo-1,3-dioxolane108-32-746.60.49
acetonitrile75-05-845.60.46
benzonitrile100-47-041.50.33
butanenitrile109-74-043.10.38
butanol71-36-350.20.60
dimethyl sulfoxide67-68-545.10.44
ethanol64-17-551.90.65
formamide75-12-756.60.80
hexamethylphosphoramide680-31-940.90.31
methanol67-56-155.40.76
N,N,N',N'-tetramethylurea632-22-441.00.32
N,N-dimethylacetamide127-19-543.70.40
N,N-dimethylformamide68-12-243.80.40
N-methylformamide123-39-754.10.72
N-methylpyrrolidone872-50-442.20.35
nitrobenzene98-95-341.20.32
nitromethane75-52-546.30.48
propanol71-23-850.70.62
sulfolane126-33-044.00.41
water7732-18-563.11.00