Carbonium Ions. I. An Acidity Function (C<sub>0</sub>) Derived from Arylcarbonium Ion Equilibria<sup>1</sup>

Deno, N. C.; Jaruzelski, John J.; Schriesheim, A.

doi:10.1021/ja01616a036

Cited by 276 publications

(115 citation statements)

References 0 publications

Supporting

Mentioning

110

Contrasting

Order By: Relevance

“…[5] is algebraically linear with 4G0/RT, as is any sum of those terms. In this sense log Q (the sunl of the three concentration terms) inakes a linear contribution to free energy change.…”

Section: Correlation Of Four Representative Collections O F Datamentioning

confidence: 99%

LINEAR FREE ENERGY RELATIONSHIPS CONCERNING EQUILIBRIA IN MODERATELY CONCENTRATED MINERAL ACIDS: A SIMPLE METHOD FOR ESTIMATING pK's OF WEAK BASES

Bunnett¹,

Olsen²

1966

Can. J. Chem.

168

View full text Add to dashboard Cite

Linear relationships exist between the logarithms of equilibrium quotients, [SH+]/[S][H+], of diverse bases as they vary with acid concentration in moderately concentrated mineral acids. For purposes of formulating these linear free energy relationships in standard form, the equilibrium quotient for protonation of a hypothetical aromatic primary amine of pK, zero has been chosen as horizontal coordinate; this is given by (-Ho -log [H+]). Log ([SH+]/[S])+ HO is plotted against (Ho + log [H+]). 'The slope, 4, of the h e a r plot is a parameter which characterizes the response of the equilibrium quotient to changing acid concentration. The intercept represents the thermodynamic pK, of the base. This constitutes a general method for estimating the pK, of any base which undergoes protonation in moderately concentrated mineral acid, with reference to the single acidity function, Ho. For bases of diverse type, pK's estimated by this method are in good agreement with those estimated by the acidity function method. Use of the new correlation procedure a s a check on the validity of several acidity functions and its application to equilibria not involving proton gain or loss are also discussed.

show abstract

“…[5] is algebraically linear with 4G0/RT, as is any sum of those terms. In this sense log Q (the sunl of the three concentration terms) inakes a linear contribution to free energy change.…”

Section: Correlation Of Four Representative Collections O F Datamentioning

confidence: 99%

LINEAR FREE ENERGY RELATIONSHIPS CONCERNING EQUILIBRIA IN MODERATELY CONCENTRATED MINERAL ACIDS: A SIMPLE METHOD FOR ESTIMATING pK's OF WEAK BASES

Bunnett¹,

Olsen²

1966

Can. J. Chem.

168

View full text Add to dashboard Cite

show abstract

“…Any or all of these factors inay undergo significant variation with changes in the medium but their relative importance is difficult to predict. Assuming for the inoment that the separation of terms in Equation [2] is valid, and that the net variation of the activity coefficient term is less important than that of the term in the water activity, we can write approximately…”

Section: Compariso?~ Of the Hi And Ho Fll~zctionsmentioning

confidence: 99%

The Ionization Behavior of Amides in Concentrated Sulphuric Acids: I. A New Acidity Function Based on a Set of Primary Amide Indicators

Yates¹,

Stevens²,

Katritzky³

1964

Can. J. Chem.

100

View full text Add to dashboard Cite

X set of eight suitably substituted primary amides of progressively weaker basicity have been prepared. Their ionization curves have been determined in sulphuric acids by spectrophotometric methods. These show good overlap and parallelism for successive indicators, enabling the pK values of the indicators to be deterlnined by direct stepwise comparison.Using these pK values and measured ionization ratios, values of a new acidity function, fI>:\, have been obtained for aqueous solutions up to 82% sulphuric acid. The H::\ function decreases much less rapidly than PI0 in this range, being nearly 3 log units less negative a t the highcst acidity studiecl. The reasons for this large difference are discussed. The $I,:\ function is shown to be applicable to other arnides which have not been elnployed as indicators.

show abstract

“…The monomethoxy compound is 100% demethylated (and the resulting phenol slowly acetylated) under our standard reduction conditions, whereas the dimethoxy compound is reduced to the corresponding diphenylmethane without demethylation. 4 The pK R+ of 4,4'-dimethoxybenzhydrol is -5.71 26 and that of 4,4'-bis[dimethylamino]benzhydrol is similar (-5.61). 23 As we have noted, these substances are reduced readily.…”

Section: Methodsmentioning

confidence: 96%

Further studies on the reduction of benzylic alcohols by hypophosphorous acid/iodine

Gordon¹,

Fry²,

Hicks³

2005

Arkivoc

View full text Add to dashboard Cite

Hydrogen iodide, generated (and regenerated) in situ by the action of iodine upon hypophosphorous acid, was found to reduce a variety of aryl carbinols to the corresponding diphenylmethanes under mild conditions. The generality of the reaction was explored by extension to several diols, heterocyclic alcohols, and allylic alcohols. Several lines of evidence, including occasional isolation of alkyl iodides, dependence of the rate of reduction upon substituent effects, and isolation of ethers and esters in the early stages of reduction, reveal that the first step in the reduction process is conversion of the alcohol to a carbocation. Isolation of dimers from cinnamyl alcohol and 1-phenyl-2-propen-1-ol demonstrates the intermediacy of radical intermediates in at least some reductions.

show abstract

Carbonium Ions. I. An Acidity Function (C₀) Derived from Arylcarbonium Ion Equilibria¹

Cited by 276 publications

References 0 publications

LINEAR FREE ENERGY RELATIONSHIPS CONCERNING EQUILIBRIA IN MODERATELY CONCENTRATED MINERAL ACIDS: A SIMPLE METHOD FOR ESTIMATING pK's OF WEAK BASES

LINEAR FREE ENERGY RELATIONSHIPS CONCERNING EQUILIBRIA IN MODERATELY CONCENTRATED MINERAL ACIDS: A SIMPLE METHOD FOR ESTIMATING pK's OF WEAK BASES

The Ionization Behavior of Amides in Concentrated Sulphuric Acids: I. A New Acidity Function Based on a Set of Primary Amide Indicators

Further studies on the reduction of benzylic alcohols by hypophosphorous acid/iodine

Contact Info

Product

Resources

About

Carbonium Ions. I. An Acidity Function (C0) Derived from Arylcarbonium Ion Equilibria1

Cited by 276 publications

References 0 publications

LINEAR FREE ENERGY RELATIONSHIPS CONCERNING EQUILIBRIA IN MODERATELY CONCENTRATED MINERAL ACIDS: A SIMPLE METHOD FOR ESTIMATING pK's OF WEAK BASES

LINEAR FREE ENERGY RELATIONSHIPS CONCERNING EQUILIBRIA IN MODERATELY CONCENTRATED MINERAL ACIDS: A SIMPLE METHOD FOR ESTIMATING pK's OF WEAK BASES

The Ionization Behavior of Amides in Concentrated Sulphuric Acids: I. A New Acidity Function Based on a Set of Primary Amide Indicators

Further studies on the reduction of benzylic alcohols by hypophosphorous acid/iodine

Contact Info

Product

Resources

About

Carbonium Ions. I. An Acidity Function (C₀) Derived from Arylcarbonium Ion Equilibria¹