THE ULTRAVIOLET ABSORPTION SPECTRA OF SEVERAL DEHYDRATION AND OXIDATION DERIVATIVES OF CHOLESTEROL

1951 ◽  
Vol 29 (5) ◽  
pp. 398-408 ◽  
Author(s):  
R. H. Cox ◽  
E. Y. Spencer
Keyword(s):  
Absorption Spectra ◽  
Wave Length ◽  
Animal Experimentation ◽  
Ultraviolet Absorption ◽  
Oxidation Products ◽  
Length Range ◽  
Enol Acetate ◽  
Enol Esters ◽  
Derivatives Of

Certain dehydration and oxidation products of cholesterol were prepared for subsequent animal experimentation. The ultraviolet absorption spectra of those derivatives possessing two or more conjugate chromophores were determined spectrophotometrically over the wave length range of 220 mμ to 350 mμ. The relative coincidence of the experimental λmax and εmax values of cholestadiene-3, 5 and of the enol acetate of cholesten–4–one–3 is offered as support for a 3, 5-diene structure for the latter steroid in particular and for enol esters of 4,5-unsaturated 3-ketosteroids in general.

Polarographic half-wave potentials and ultraviolet absorption spectra of some conjugated heteroenoid compounds

1969 ◽  
Vol 47 (21) ◽  
pp. 4076-4083 ◽  
Author(s):  
H. L. Holmes ◽  
D. J. Currie
Keyword(s):  
Absorption Spectra ◽  
Functional Groups ◽  
Ultraviolet Absorption ◽  
Half Wave ◽  
Active Methylene Compounds ◽  
Derivatives Of ◽  
Active Methylene ◽  
Hammett Relationship

The half-wave potentials of phenyl substituted derivatives for each series of conjugated heteroenoid compounds studied follow a Hammett relationship. The effect of change in the functional groups and of increase in length of the conjugated system upon half-wave potentials and ultraviolet absorption maxima is briefly discussed. Terephthalylidene derivatives of active methylene compounds function like the cinnamylidene derivatives.

THE ULTRAVIOLET ABSORPTION SPECTRA OF SOME CARBOXY DERIVATIVES OF NAPHTHALENE

1949 ◽  
Vol 27b (5) ◽  
pp. 437-461 ◽  
Author(s):  
Y. Hirshberg ◽  
R. Norman Jones
Keyword(s):  
Dicarboxylic Acid ◽  
Absorption Spectra ◽  
General Problem ◽  
Acid Anhydride ◽  
Ultraviolet Absorption ◽  
Dioxane Solution ◽  
Ethanolic Solution ◽  
Complex Molecules ◽  
Steric Inhibition Of Resonance ◽  
Derivatives Of

The ultraviolet absorption spectra of a variety of naphthalene compounds containing phenyl and carboxy substituents are described. The majority of the compounds contain either the naphthalene-1,2-dicarboxylic acid anhydride or the naphthalene-2,3-dicarboxylic acid anhydride ring systems. It is shown that in ethanolic solution the spectra of these anhydrides change over a period of a few hours. The spectra of the anhydrides in n-heptane or dioxane solution do not change on standing. The effects of the various substituents are discussed in terms of steric inhibition of resonance and of antagonistic and reinforcing actions of the substituents, dependent on the position of substitution. The significance of these data are considered in relation to the general problem of the interpretation of the ultraviolet absorption spectra of complex molecules.

Functional group and substituent effects, both steric and electronic, upon the ultraviolet absorption spectra of some N-alkyl- and N,N-dialkyl-derivatives of some cinnamamides and benzalcyanoacetamides

1969 ◽  
Vol 47 (17) ◽  
pp. 3278-3280 ◽  
Author(s):  
A. D. Delaney ◽  
D. J. Currie ◽  
H. L. Holmes
Keyword(s):  
Hydrogen Atom ◽  
Absorption Spectra ◽  
Functional Group ◽  
Substituent Effects ◽  
Ultraviolet Absorption ◽  
Long Wavelength ◽  
Wavelength Absorption ◽  
Derivatives Of

Conjugative and steric constants for N-substituted carboxyamide groups have been derived which allow the calculation of the long wavelength absorption maxima of N-alkyl- and N,N-dialkyl-derivatives of cinnamamide and benzalcyanoacetamide. Deviations between calculated and observed values indicate that there may be steric interference between bulky N,N-dialkylcarboxyamide groups and the benzylic hydrogen atom.

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