The transmission of polar effects. Part X. The esterification with diazodiphenyl-methane and the ionization of 9-substituted 10-anthroic and 8-substituted 1-naphthoic acids

The rate coefficients for the reaction with diazodiphenylmethane in methanol, ethanol, isopropyl alcohol, t-butyl alcohol, 2-methoxyethanol, 2-n-butoxyethanol, and ethyl acetate at 30° and the pKa values in 80% 2-n-butoxyethanol–water of a series of 9-substituted 10-anthroic and 8-substituted 1-naphthoic acids have been determined. The effect of substitution has been analyzed by linear free energy relations. The variation in the susceptibilities of the systems to polar substituent effects with the medium are examined. The occurrence of reversed dipolar substituent effects in the reactions of the 1,8-naphthoic acids is detected. The implications of the results for the inductive and field effect models for the transmission of polar effects are discussed.

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The transmission of polar effects. Part IX. The ionization and esterification with diazodiphenylmethane of 9-substituted 10-triptoic acids

Canadian Journal of Chemistry ◽

10.1139/v69-024 ◽

1969 ◽

Vol 47 (2) ◽

pp. 177-183 ◽

Cited By ~ 7

Author(s):

Keith Bowden ◽

D. C. Parkin

Keyword(s):

Free Energy ◽

Field Effect ◽

Inductive Effect ◽

Rate Coefficients ◽

Linear Free Energy ◽

Effect Model ◽

Energy Relations

A series of 9-substituted 10-triptoic acids have been prepared. Their pKa values in 80% 2-methoxy-ethanol–water and 50% ethanol–water at 25° and rate coefficients for esterification with diazodiphenyl-methane in five alcohols at 30° have been measured. The results have been analyzed by linear free energy relations. The π-inductive effect is shown to be unimportant in such systems, while the field effect model can account for the transmission.

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The transmission of polar effects. Part V. The kinetics of esterification with diazodiphenylmethane and the ionization of substituted acetic and propionic acids in several solvents

Canadian Journal of Chemistry ◽

10.1139/v68-487 ◽

1968 ◽

Vol 46 (18) ◽

pp. 2929-2940 ◽

Cited By ~ 11

Author(s):

Keith Bowden ◽

M. Hardy ◽

D. C. Parkin

Keyword(s):

Isopropyl Alcohol ◽

Butyl Alcohol ◽

Rate Coefficients ◽

Esterification Reaction ◽

Linear Free Energy ◽

Ionization Reaction ◽

Reaction Constants ◽

Polar Substituents ◽

Energy Relations ◽

Kinetics Of

The rate coefficients for the reaction with diazodiphenylmethane in methanol, ethanol, isopropyl alcohol,t-butyl alcohol, 2-methoxyethanol, 2-n-butoxyethanol, dimethyl sulfoxide, ethyl acetate, and toluene at 30° and the pKa values in water, 50% ethanol–water, and 80% 2-methoxyethanol–water of 18 substituted acetic and propionic acids have been determined. A further 14 acids have been studied to a more limited extent. The effect of substitution has been estimated by linear free energy relations. The reaction constants for the ionization reaction are almost independent of the medium. This is interpreted as being due to the field effect of the proximate polar substituents passing through the molecular cavity almost alone. The occurrence of steric inhibition of solvation causing acid weakening for bulky multi-substitution is confirmed. The reaction constants for the esterification reaction are affected by the solvent. This is attributed to dependence on solvation of the transition state.

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The transmission of polar effects. Part VII. A proton magnetic resonance spectra study of substituted mesitylenes, durenes, anthracenes, and triptycenes

Canadian Journal of Chemistry ◽

10.1139/v68-644 ◽

1968 ◽

Vol 46 (24) ◽

pp. 3903-3908 ◽

Cited By ~ 6

Author(s):

Keith Bowden ◽

J. G. Irving ◽

M. J. Price

Keyword(s):

Dielectric Constant ◽

Free Energy ◽

Carbon Tetrachloride ◽

Field Effect ◽

Proton Magnetic Resonance ◽

Chemical Shifts ◽

Linear Free Energy ◽

Solvent Dependence ◽

Similar Dependence ◽

Energy Relations

The chemical shifts of the ring protons in a series of monosubstituted mesitylenes and durenes, and of the 10-protons of a series of 9-substituted triptycenes and anthracenes have been measured in dimethyl sulfoxide, acetone, 2-methoxyethanol, and carbon tetrachloride. The solvent dependence of the substituent chemical shifts has been analyzed by linear free energy relations. The systems all show similar dependence which increases with increasing dielectric constant of the solvent. This does not result from the field effect being transmitted through the medium, but appears to arise from the formation of a hydrogen-bonded interaction between the solvent and the hydrogen of the solute. The substituent chemical shifts appear to arise from contributions from substituent field, resonance, magnetic anisotropy, and solvent effects.

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THE TRANSMISSION OF POLAR EFFECTS: PART II. THE KINETICS OF ESTERIFICATION WITH DIAZODIPHENYLMETHANE AND THE IONIZATION OF 3-SUBSTITUTED ACRYLIC ACIDS

Canadian Journal of Chemistry ◽

10.1139/v65-466 ◽

1965 ◽

Vol 43 (12) ◽

pp. 3354-3363 ◽

Cited By ~ 21

Author(s):

Keith Bowden

Keyword(s):

Butyl Alcohol ◽

Polar Effect ◽

Rate Coefficients ◽

Strengthening Effect ◽

Benzoic Acids ◽

Linear Free Energy ◽

Substituted Benzoic Acids ◽

Energy Relations ◽

Acrylic Acids ◽

Kinetics Of

The rate coefficients for the reaction with diazodiphenylmethane in ethanol, t-butyl alcohol, and ethyl acetate at 30° and the pKa values in water at 25° of fourteen 3-substituted acrylic acids have been determined. The effect of substitution is assessed by use of linear free energy relations. A definite incremental acid-strengthening effect solely due to cis-substitution is confirmed. This is not a "bulk" steric effect and is due solely to the orientation of substitution. The polar effect of a substituent is found to be approximately the same from the cis- or trans-position. An attempt is made to test the suggested mechanisms for the transmission of the polar effect. In the reactions studied the transmission of the polar effect in 3-substituted acrylic acid and ortho-substituted benzoic acids is approximately twice that of the meta- or para-substituted benzoic acids. This appears to be reasonably accommodated by a significant field effect.

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