ET-value, \(E_{\text{T}}\)

https://doi.org/10.1351/goldbook.E02222
See: Dimroth–Reichardt ET parameter, Z-value
Source:
PAC, 1994, 66, 1077. 'Glossary of terms used in physical organic chemistry (IUPAC Recommendations 1994)' on page 1108 (https://doi.org/10.1351/pac199466051077)