Host: Division of Chemical Information and Computer Science, The Chemical Society of Japan
Co-host: The Pharmaceutical Society of Japan, Japan Society for Bioscience, Biotechnology, and Agrochemistry, The Japan Society for Analytical Chemistry, Japan Chemistry Program Exchange, Japanese Society for Information and Systems in Education (Approaval)
Pages JK10
The linear free energy relationships, exemplified by the Hammett and the Broensted equations, are of course empirically based and both assumed to be essentially linear. The Yukawa-Tsuno equation is required to ensure the linearity for the region the original Hammett equation otherwise fails. On the other hand, the establishment of the intrinsic non-linearity in the Broensted relationship has lead to the concept of the selectivity reactivity relationship intimately related to the rate-equilibrium relationship-coordinate shifts of transition state. This elegant concept has now been widely used to the quantitative elucidation of the Hammett-type structure-reactivity correlations in benzyl cationic systems. Non-additivity and non-linearity of substituent effects observed in the polyarylcarbenium systems were elucidated rather elegantly in such a way based on the shifts of transition state coordinate. The most of well-known successful results are criticized, demonstrating no change in transition state position.