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.

THE NUCLEAR MAGNETIC RESONANCE SPECTRA OF PARA-SUBSTITUTED PHENOLS

1962 ◽  
Vol 40 (11) ◽  
pp. 2122-2125 ◽  
Author(s):  
W. G. Paterson ◽  
N. R. Tipman
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Carbon Tetrachloride ◽  
Magnetic Resonance ◽  
Infinite Dilution ◽  
Chemical Shifts ◽  
Substituted Phenols ◽  
Linear Relationships ◽  
Nuclear Magnetic Resonance Spectra ◽  
Magnetic Resonance Spectra ◽  
Nuclear Magnetic

The nuclear magnetic resonance spectra of a number of para-substituted phenols have been examined. The —OH chemical shifts, extrapolated to infinite dilution in benzene and in carbon tetrachloride, were found to be almost independent of the nature of the ring substituent. Approximately linear relationships were observed between the internal chemical shift of the ring protons and other physical properties.

An Experimental Study of Linear Inclination

1974 ◽  
Vol 26 (1) ◽  
pp. 52-62 ◽  
Author(s):  
Gerald H. Fisher
Keyword(s):  
Experimental Study ◽  
Angular Distortion ◽  
Perceptual Distortion ◽  
Single Straight Line ◽  
Straight Line ◽  
Two Component

Two mechanisms have been proposed to account for perceptual distortion of angular subtension. The first implies that errors made when estimating sizes of angles should correspond to inaccuracies of estimating the inclinations of their two component lines. From the second it follows that the two types of judgement are unrelated. This paper considers which of these mechanisms accounts most consistently for apparent angular distortion. Two experiments are reported. In the first, four independent groups of subjects estimated the bearing of a single straight line presented in a series of inclinations throughout the entire circular range. Subjects themselves attempted to place the same line into specified inclinations in the second experiment. The results reveal errors in both tasks. An attempt is made to distinguish between the two proposed mechanisms by predicting angular distortions from those of corresponding linear inclinations. Possible reasons for failure of this prediction are discussed.

Determination of optical constants and vibrational band intensities of liquids in the infrared using attenuated total reflexion

1967 ◽  
Vol 298 (1453) ◽  
pp. 160-177 ◽  
Keyword(s):  
Refractive Index ◽  
Carbon Tetrachloride ◽  
Working Conditions ◽  
Optical Constants ◽  
Carbon Disulphide ◽  
Absorption Bands ◽  
Total Reflexion ◽  
Solid Liquid Interface ◽  
Solid Liquid

The refractive index, and vibrational absorption band intensities, of some liquids have been determined by a new method involving attenuated total reflexion at a solid liquid interface. The principles of the method have been explained and the factors which determine a choice of optimal working conditions have been discussed. The method has been applied to absorp­tion bands of benzene, carbon tetrachloride, chloroform, bromoform, sym -tetrabromo-ethane, and carbon disulphide. Data have been obtained on the variation of refractive index across the absorption bands, and the computed band intensities have been compared with those obtained previously by other methods.

Factor analysis as a complement to band resolution. V. Complexing of pentachlorophenol and acetone in carbon tetrachloride solution

1978 ◽  
Vol 56 (23) ◽  
pp. 2959-2965 ◽  
Author(s):  
J. Korppi-Tommola ◽  
H. F. Shurvell
Keyword(s):  
Factor Analysis ◽  
Carbon Tetrachloride ◽  
Complex Formation ◽  
Infrared Spectrum ◽  
Equilibrium Constants ◽  
Complex Model ◽  
Carbon Tetrachloride Solution ◽  
Linear Relationships

Complex formation between pentachlorophenol and acetone and acetone-d6 in carbon tetrachloride solution has been studied in both the hydroxyl and carbonyl stretching regions of the infrared spectrum. Factor analysis of the digitized spectra indicates three absorbing components for each set of solutions in the hydroxyl stretching region. Concentration studies revealed roughly linear relationships between the areas of the 'free' ν(OH) band and both of the resolved complex bands, suggesting that two different 1:1 complexes occur in CCl4 solution. In the ν(CO) region only one band due to complex formation was detected. Equilibrium constants for the isotopically different complexes at about 30 °C are reported. In the hydroxyl stretching region, band resolution was also carried out using four components which gave a better fit to the observed spectrum. A set of equilibrium constants were then obtained. However, considerable difficulties were met in the calculations and in the interpretation of these results, so that the three band, two complex model is preferred.

Substituent and solvent effects on the reaction between 2,6-Di-t-butyl-α-(3,5-di-t-butyl-4-oxocyclohexa-2,5-dien-1-ylidene)-p-tolyloxyl (galvinoxyl) and phenols

1978 ◽  
Vol 31 (6) ◽  
pp. 1201 ◽  
Author(s):  
N Nishimura ◽  
K Okahashi ◽  
T Yukutomi ◽  
A Fujiwara ◽  
S Kubo
Keyword(s):  
Carbon Tetrachloride ◽  
Binary Mixtures ◽  
Solvent Effects ◽  
Rate Constants ◽  
Isotope Effects ◽  
Mixed Solvents ◽  
Transition States ◽  
Activation Parameters ◽  
Substituted Phenols ◽  
Kinetic Behaviour

Rate constants and associated activation parameters for the reaction of galvinoxyl with substituted phenols were obtained in carbon tetrachloride and in cyclohexane-dioxan binary mixtures. Substantial isotope effects were observed for O-deuterated phenols. The rate constants are correlated with σ+ values. These findings are discussed by considering the polar contribution of substituents to the stabilization of the transition states. In the mixed solvents, the kinetic behaviour is well expressed by the equations which are based on the theory of Kondo and Tokura.

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