THE EFFECT OF SUBSTITUENTS ON THE RELATIVE RATES OF REACTION OF tert-BUTOXY RADICALS WITH PHENOLS IN CARBON TETRACHLORIDE AND IN CHLOROBENZENE

1963 ◽  
Vol 41 (11) ◽  
pp. 2816-2825 ◽  
Author(s):  
K. U. Ingold
Keyword(s):  
Carbon Tetrachloride ◽  
Transition State ◽  
Hydrogen Abstraction ◽  
Substituted Phenols ◽  
Aromatic Solvent ◽  
Effect Of Substituents

The relative rates of hydrogen abstraction from substituted phenols by t-butoxy radicals can be correlated with the σ+ constants of the substituents. The effects of an aromatic solvent (chlorobenzene) and of ortho-alkyl substituents on the reactivities of the phenols and on the transition state of the reaction are discussed.

CORRELATION OF O–H STRETCHING FREQUENCIES WITH pK VALUES FOR SOME PHENOLS

1957 ◽  
Vol 35 (12) ◽  
pp. 1555-1560 ◽  
Author(s):  
P. M. G. Bavin ◽  
William J. Canady
Keyword(s):  
Carbon Tetrachloride ◽  
Carboxylic Acids ◽  
Carbon Disulphide ◽  
Substituted Phenols ◽  
Electrostatic Effects ◽  
Single Straight Line ◽  
Linear Relationships ◽  
Straight Line ◽  
Alcohol Water

The O–H stretching frequencies, in carbon disulphide, of a number of phenols have been determined. Linear relationships were observed on plotting the stretching frequency against pKA in water. Polar substituted phenols were found to fall along one line, while phenols substituted with aliphatic groups were found to fall along another line of different slope. A change of slope is observed when the stretching frequencies of phenols are plotted against pKA measured in alcohol–water mixtures.Using Goulden's O–H stretching frequencies of carboxylic acids measured in carbon tetrachloride, an attempt has been made to explain the observed deviations from a single straight line in terms of electrostatic effects in the ionizing solvent. The results indicate that for the substances examined, such effects are not responsible for the observed deviations.

Sign in / Sign up

Export Citation Format

Share Document