A Exponent

A,B) = Z Zg(sASB sASB)(l +e where the a exponents are taken as fitting parameters. 

For hydration (Dubois et al, 1981a), there is a significant decrease in the sensitivity to Y with increasing reactivity, but it is smaller than that for bromination. The p-values for these additions are linearly related to each other, but bromination is twice as sensitive to ring substituent effects compared with hydration (Fig. 13). However, constant Bronsted a-exponents show that, in contrast to bromination, there is no marked shift in the transition state of hydration. 

Dastart starting value a for the Damkoehler number 10 a (exponent)... 

Obviously, these results cannot be explained by a very enol-like transition state. This does not mean that enol stability does not affect reactivity, but that it probably does so to a lesser extent than at first expected. Such a conclusion runs counter to the first assertions and to what is usually assumed (see e.g. Lamaty, 1976), but is in agreement with the data cited above concerning Bronsted a-exponents. Indeed, the a-value of 0.74 observed for acid-catalysed enolisation of cyclohexanone (Lienhard and Wang, 1969) corresponds to a relatively early transition state since the Bronsted / for base-promoted proton abstraction from the hydroxycarbenium ion intermediate [see eqn (3)] equals 1 — 0.74, or 0.26. As pointed out above, some data on the stereochemistry of ketonisation were accounted for by assuming an enol-like transition state. Clearly, these interpretations need to be re-examined. 

Where the symbols used have the following meaning Mi = molar mass of the component molecules of kind i nj = number-fraction of the component molecules i Wj = weight-fraction of the component molecules i N = total number of moles of all kinds W = total weight of moles of all kinds a = exponent of the Mark-Houwink relationship relating intrinsic viscosity to molar mass. 

The variation in the p values in a closely related series of reactions can be related to the cationic charge developed at the reaction centre in the transition state. Thus, a corollary of the RSR is that the coefficient S should be a measure of whether the transition state occurs early or late on the reaction coordinate as a result of any structural perturbation of the energy of the transition state as well as of the intermediate in the reaction series. The S coefficient in an RSR should be intimately related to the a exponent in the extended Brpnsted equation (cf., Johnson, 1980). 

Although the value of the coefficient 1.16 in (20) does not have as direct a physical significance as the a-exponent in the extended Brpnsted equation (19) because the reaction, solvents and temperature are different, there is still a good linear rate-equilibrium relationship for benzhydryl carbocation formation the overall correlation embraces clearly concave partial correlations with varying slopes for the respective Y series. The whole pattern of substituent effects, pXr vs should be essentially identical (with only the ordinate scale being slightly different) to that of log (/ xy/Z hh) vs 2 a for the solvolyses shown in Fig. 8. 

All entries are in relative values lsee Appendix A), Exponents and contraction coefficients for nitrogen and, hydrogen according to Ref. 51 and Ref. 38, respectively,... 

Co concentration of molecules on the surface of the explosive, n number of the nitro groups in the molecule, a exponent varying from 1.5 to 2. 

This relation gives us the correction to the finite-size critical exponent obtaining the exact a exponent for Hamiltonian (20) as... 

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