Transition states, structure in solution, cross-interaction constants and

Cross-interaction constants and transition-state structure in solution, 27, 57 Crown-ether complexes, stability and reactivity of, 17,279 Crystallographic approaches to transition state structures, 29,87 Cyclodextrins and other catalysts, the stabilization of transition states by, 29,1... 

Cross-interaction Constants and Transition-state Structure in Solution... 

Tetrahedral intermediates, derived from carboxylic acids, spectroscopic detection and the investigation of their properties, 21, 37 Topochemical phenomena in solid-state chemistry, 15, 63 Transition state structure, crystallographic approaches to, 29, 87 Transition state structure, in solution, effective charge and, 27, 1 Transition state structure, secondary deuterium isotope effects and, 31, 143 Transition states, structure in solution, cross-interaction constants and, 27, 57 Transition states, the stabilization of by cyclodextrins and other catalysts, 29, 1 Transition states, theory revisited, 28, 139... 

Transition stale structure, secondary deuterium isotope effects and, 31, 143 Transition states, structure in solution, cross-interaction constants and, 27, 57 Transition states, the stabilization of by cyclodextrins and other catalysts, 29, 1 Transition states, theory revisited, 28, 139... 

Gas-phase nucleophilic substitution reactions of Y-benzyl chlorides and X-phenoxide or X-thiophenoxide nucleophiles have been investigated by using the PM3 semiempirical MO method. The structure of the transition state was examined. The values of the gas-phase Hammett constants px and py are much greater than for the solution reactions, but a theoretical cross-interaction constant pxy (ca —0.60 for both phenoxides and thiophenoxides) agrees well with an experimental value of —0.62 for the thiophenoxide reactions in MeOH at 20 °C. Other work by the same group has involved theoretical studies of competitive gas-phase 5 n2 and E2 reactions of NCCH2CH2CI with HO and An ab initio method at the 6-31-l-G level was... 

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