## Dimroth–Reichardt ET parameter, $$E_{\textrm{T}}$$

https://doi.org/10.1351/goldbook.D01746
A measure of the @I03215@ (loosely @P04710@) of a solvent, based on the maximum wavenumber of the longest @W06659@ electronic absorption band of:
D01746.png
in a given solvent. $$E_{\text{T}}$$, called $$E_{\text{T}}\left(30\right)$$ by its originators, is given by: $E_{\text{T}}=2.859\times 10^{- 3}\ \nu =2.859\times 10^{4}\ \lambda ^{- 1}$ where $$E_{\text{T}}$$ is in $$\mathrm{kcal}\ \mathrm{mol}^{- 1}$$, $$\nu$$ is in $$\mathrm{cm}^{- 1}$$ and $$\lambda$$ is in $$\mathrm{nm}$$. The so-called normalized $$E_{\text{T}}^{\text{N}}$$ scale is defined as: $E_{\text{T}}^{\text{N}}=\frac{E_{\text{T}}\left(\text{solvent}\right)- E_{\text{T}}\left(\text{Si}\text{Me}_{4}\right)}{E_{\text{T}}\left(\text{water}\right)- E_{\text{T}}\left(\text{Si}\text{Me}_{4}\right)}=\frac{E_{\text{T}}\left(\text{solvent}\right)- 30.7}{32.4}$
Grunwald–Winstein equation
,
Z-value
Source:
PAC, 1994, 66, 1077. (Glossary of terms used in physical organic chemistry (IUPAC Recommendations 1994)) on page 1106 [Terms] [Paper]