Dimroth–Reichardt ET parameter

A measure of the ionizing power (loosely polarity) of a solvent, based on the maximum wavenumber of the longest wavelength electronic absorption band of:

in a given solvent. $E T$ , called $E T 30$ by its originators, is given by:

$E T = 2.859 × 10 −3 ν = 2.859 × 10 4 λ −1$

where $E T$ is in $kcal mol −1$ , $ν$ is in $cm −1$ and $λ$ is in $nm$ . The so-called normalized $E T N$ scale is defined as:

$E T N = E T solvent − E T Si Me 4 E T water − E T Si Me 4 = E T solvent − 30.7 32.4$

See also: Grunwald–Winstein equation, Z-value

Source:

PAC, 1994, 66, 1077 (Glossary of terms used in physical organic chemistry (IUPAC Recommendations 1994)) on page 1106

Dimroth–Reichardt parameter

Dimroth–Reichardt $E T$ parameter