Yukawa- Tsuno Equation (Paperback)

High Quality Content by WIKIPEDIA articles The Yukawa-Tsuno Equation, first developed in 1959, is a linear free energy relationship in physical organic chemistry. It is a modified version of the Hammett equation that accounts for enhanced resonance effects in electrophilic reactions of para- and meta-substituted organic compounds. This equation does so by introducing a new term to the original Hammett relation that provides a measure of the extent of resonance stabilization for a reactive structure that builds up charge (positive or negative) in its transition state.The Hammett substituent constant,, is composed of two independent terms: an inductive effect I and a resonance polar effect R. These components represent the consequences of the presence of a particular substituent on reactivity through sigma and pi bonds, respectively.