Energy relationship with

Figure 19 (bottom) shows that the cleavage of alkylmetals by mercuric chloride follows an apparent negative Br nsted slope a (left figure). However, when the work term Wp is included with EqX, the curved free energy relationship with negative slopes is transformed into the linear correlation shown on the right. 

Taft, R. W., Gurka, D., Joris, L., Schleyer, P. V., Rakshys, J. W., Studies of hydrogen-bonded complex formation with P-fluorophenol. V. linear free energy relationships with OH reference acids. J. Am. Chem. Soc. 1969, 91, 4801-4808. 

Kong, Y. and Warshel, A. (1995). Linear free energy relationships with quantum mechanical corrections classical and quantum mechanical rate constants for hydride transfer between NAD+ analogues in solutions. J. Am. Chem. Soc. 117, 6234—6242... 

In the same way, Abraham has calculated, from partition coefficients, an effective or summation hydrogen-bonding acidity scale, half - However, while sot is obtained from one reference partition system (octanol/chloroform), with the hypothesis that a number of solute parameters acting on log P cancel out, Abraham determines the haf values by a back calculation procedure over numerous sets of partition systems, and uses linear solvation energy relationships with a more complete set of solute parameters. Table 7 shows that Ea > ea and af values do not differ much for simple mono hydrogen-bond donors. It is also important to note that the order of acidity ... 

Taft RW, Gurka D,Joris L, Schleyer P, von R, and RakshysJW. Studies of Hydrogen-bonded complex formation with p-fluorophenol. V. Linear Free Energy Relationships with OH Reference Acids./Am Chem Soc 1969 91 4801-4808. 

Kong, Y., Warshel, A., Linear Free Energy Relationships with Quantum Mechanical Corrections Classical and Quantum Mechanical Rate Constants for Hydride Transfer Between NAD" " Analogues in Solutions, J. Am. Chem. Soc. 1995, 117, 6234-6242. 

Solvent effects are essentially free-energy correlations [57] and we shall omit in this chapter those of strongly acidic media as these are clearly not pertinent to biochemistry. The effect of variation of solvent on a rate or equilibrium constant may be treated in the same way as a substituent effect. We may apply the same criteria to elucidate mechanistic or rate-determining step changes to free-energy relationships with solvent effects. Let us consider the hydrolysis of 5-phenyl-oxazoline-2-ones... 

The philicity of singlet carbenes is an important concept to classify carbenes that was systematically studied by Moss. [9-11] The relative reactivity (selectivity) of a series of singlet carbenes in cyclopropanation reactions with electron rich and electron poor carbenes was used to quantify the carbene philicity. An empirical carbene philicity scale with a parameter niQ- (where X and Y are the substituents at the carbene center) was defined (Figure 1). Electrophilic carbenes show Wqxy values below 1, nucleophilic carbenes above 2, and ambiphiles are between. [10] Ambiphilic carbenes act as an electrophile towards electron-rich alkenes and as a nucleophile towards electron-poor alkenes. The niQ- Y values obey an empirical linear free energy relationship with the Taft substituent parameters and Oj. This allows to estimate the niQ- Y values of unknown carbenes. 

Table 3 Linear free-energy relationships with RhCl(PPh3)3...

Table 4 Linear free-energy relationships with [RhCl(C2H4)2]2...

Use as a Nucleophile. The rate of nucleophilic substitution of 1,3-dichloropropane with potassium acetate in a range of polar solvents has been studied and correlates with the solubility of the salt. Quaternary ammonium salts (e.g., triethyl ammonium chloride, TEAC) catalyze these nucleophilic reactions by solubilizing the acetate anion. The relative rates of nucleophilic substitution of variously substituted 2-chloroethyl compounds with KOAc in DME and TEAC/MeCN solutions have a Unear free-energy relationships with the Taft substituent constant, a, showing that these reactions proceed through nucleophilic attack of acetate on RCH2CH2CI (eq 1). ... 

Halo-3-deoxychloramphenicols, the derivatives of Cm in which the 3-OH is replaced by a halogen, are competitive inhibitors. The affinity of the inhibitors to the enzyme shows a linear free energy relationship with hydrophobicity (17). 

The solubilities of RTILs in water (in terms of g L ) were predicted by Cho et al. [421] by means of linear solvation energy relationships with three to eight parameters in several alternative equations (the parameters were, but the equations were not provided in the paper) with a standard deviation of 0.14. 

Catalysis of CH4 oxidation to CH3OH by [Pd(Cp3C02)2] has been reported, and selective oxidation to CF3CO2CH3 is found in the presence of [Co(CF3C02)2] in CF3CO2H solution. " The kinetics of the outer-sphere oxidation of dienes by [Fe(phen)3] " and derivates in CH3CN solution, Eq. (24), have been studied. There is a linear free-energy relationship with the reduction potential of the oxidant. 

Revelli, A.-L. Mutelet, F. Jaubert, J.-N. (2010a). Prediction of partition coefficients of organic compounds in ionic liquids Use of a linear solvation energy relationship with parameters calculated through a group contribution method. Ind. Eng. Chem. Res., 8,49, 3883-3892. 

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