Transmission of substituent effects in anthracene. Acid dissociation constants of 10-substituted-9-anthroic acids and substituent chemical shifts of 10-substituted-9-fluoroanthracenes. Evidence for the .pi. inductive effect

1971 ◽  
Vol 93 (25) ◽  
pp. 6984-6988 ◽  
Author(s):  
Gloria L. Anderson ◽  
Roger C. Parish ◽  
Leon M. Stock
Keyword(s):  
Inductive Effect ◽  
Dissociation Constants ◽  
Chemical Shifts ◽  
Substituent Effects ◽  
Acid Dissociation ◽  
Acid Dissociation Constants

Preparation and nuclear magnetic resonance studies of diaryloxytriphenylphosphoranes. Correlation of substituent effects with 31P N.M.R. chemical shifts

1984 ◽  
Vol 37 (12) ◽  
pp. 2447 ◽  
Author(s):  
Mv Itzstein ◽  
ID Jenkins
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Dissociation Constants ◽  
Chemical Shifts ◽  
Substituent Effects ◽  
Acid Dissociation ◽  
Linear Free Energy Relationship ◽  
Acid Dissociation Constants ◽  
Magnetic Resonance Studies ◽  
Linear Free Energy ◽  
Electron Donating Groups

Triphenylphosphine and diisopropyl azodicarboxylate react with phenols in tetrahydrofuran or chloroform at 0° to give diaryloxytriphenylphosphoranes. A linear free-energy relationship has been found between the 31P n.m.r. chemical shifts of many of these phosphoranes and the acid dissociation constants of the corresponding phenols. In general, electron-withdrawing groups on the phenol result in downfield 31P n.m.r. chemical shifts, while electron donating groups result in up-field shifts.

Substituent effects on polarographic reduction of some photographic color intermediates

1976 ◽  
Vol 54 (8) ◽  
pp. 1205-1210 ◽  
Author(s):  
Ahmad S. Shawali ◽  
Bahgat E. El-Anadouli
Keyword(s):  
Dissociation Constants ◽  
Substituent Effects ◽  
Protonated Form ◽  
Acid Dissociation ◽  
Polarographic Reduction ◽  
Substituent Constant ◽  
Acid Dissociation Constants ◽  
Controlled Potential Electrolysis ◽  
Half Wave ◽  
Controlled Potential

Polarographic reduction of two series of benzoylacetanilides has been investigated in 40% (by volume) ethanolic Britton–Robinson buffers. One series (A) contains substituents on the anilide moiety, and the second (B) has substituents on both the anilide and benzoyl moieties. Polarographic controlled-potential electrolysis data indicate that the electroactive species in both series is the protonated form (ArCOCH2CONHAr′)H+. The reduction half-wave potentials of anilides of series A were found to be independent of the nature of the substituent, whereas those of series B show a good linear relationship when plotted vs. the σ substituent constant of the substituent on the benzoyl moiety (ρ = 0.284, r = 0.995). Values of the acid dissociation constants of the keto (K1) and enol (K2) tautomers of the anilides of series A were calculated; unlike their E1/2 values, the pK1 data show a linear correlation with the Hammett substituent constant, σ. The pK2 values show, however, little variation with σ.

Substituent effects on acid dissociation constants of N,N-substituted dithiocarbamic acids

1973 ◽  
Vol 45 (2) ◽  
pp. 363-367 ◽  
Author(s):  
Vernon L. Frampton ◽  
William J. Evans ◽  
James C. Kuck
Keyword(s):  
Dissociation Constants ◽  
Substituent Effects ◽  
Acid Dissociation ◽  
Acid Dissociation Constants

Chemometric Analysis of Substituent Effects. VII. Inductive Effect as a Basic Substituent Effect. Isoeffect Substituent Constant

1995 ◽  
Vol 60 (8) ◽  
pp. 1316-1332 ◽  
Author(s):  
Oldřich Pytela ◽  
Aleš Halama
Keyword(s):  
Inductive Effect ◽  
Chemical Shifts ◽  
Quantitative Description ◽  
Substituent Effects ◽  
Intersection Point ◽  
Chemometric Analysis ◽  
Reaction Centre ◽  
Substituent Constant ◽  
Modified Method ◽  
Substituted Benzoic Acids

The paper deals with chemometric analysis of the inductive effect. The notion of inductive effect is discussed, and unambiguous definitions are given for the notions of triad: reaction centre-basic skeleton-substituent, and the therewith connected definitions of inductive effect. For a quantitative description of inductive effect 7 types of chemical models were selected including noncyclic compounds, cyclic, and bicyclic compounds, derivatives of quinuclidine, 3-substituted benzoic acids, sulfonamides and pyridines. Altogether 139 sets of experimental data from literature have been used including altogether 1 294 points (9.3 points per set, 5 points at least) reflecting substituent effects of 34 substituents. It has been found that for a standard model the dissociation of substituted bicycloalkanecarboxylic acids only is satisfactory, all the other models reflecting also the mesomeric effects to variable extent (up to 10%). A distinctly different substitution behaviour was observed with 19F and 13C NMR chemical shifts of 4-substituted 1-fluoro- or 1-methylbicyclo[2.2.2]octanes. The earlier suggested model of substituent effects based on different way of transmission of substituent effects (3 classes) has been used for separating the inductive and mesomeric effects: it is mathematically presented as a set of straight lines with the intersection point at the so-called isoeffect substituent constant. Using the modified method of conjugated deviations a chemometric scale has been created for the inductive effect which agrees very well with the conventional scales given in literature; the only differences were observed for F and CH=O substituents (which are overestimated and underestimated, respectively, in literature). In the context given the inductive effect appears as a fundamental quantity forming a basis for quantitative description of other effects transferred by electrons.

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