SOME METHYL ETHERS AND ACETATES OF PURPUROGALLIN

1952 ◽  
Vol 30 (4) ◽  
pp. 251-256
Author(s):  
G. Denis Thorn ◽  
L. R. C. Barclay
Keyword(s):  
Absorption Spectra ◽  
Dimethyl Ether ◽  
Monomethyl Ether ◽  
Ultraviolet Absorption ◽  
Derivatives Of

The preparation and ultraviolet absorption spectra of a number of methyl ethers and acetates of purpurogallin are given. The following derivatives of purpurogallin are, to our knowledge, not mentioned in the literature: a mono-acetate, m.p. 182-183 °C.; a diacetate I, m.p. 159–160 °C; a diacetate II, m.p. 208–209 °C.; a triacetate, m.p. 161.5–162.5 °C.; a monomethyl ether diacetate, m.p. 156–157 °C.; a dimethyl ether diacetate, m.p. 194-196 °C. Comparison of the ultraviolet absorption spectra with those determined for derivatives of known structure suggested the positions of the acetyl groups in the new substances now prepared.

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.

Ultraviolet absorption spectra of derivatives of symmetric triazine—III The guanyl-melamines

1959 ◽  
Vol 15 ◽  
pp. 962-968 ◽  
Author(s):  
R.C. Hirt ◽  
F. Halverson ◽  
F.T. King
Keyword(s):  
Absorption Spectra ◽  
Ultraviolet Absorption ◽  
Derivatives Of

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.

Preparation and Ultraviolet Absorption Spectra of Some Derivatives of Phosphafluorinic Acid1

1959 ◽  
Vol 24 (5) ◽  
pp. 638-641 ◽  
Author(s):  
LEON D. FREEDMAN ◽  
G. O. DOAK
Keyword(s):  
Absorption Spectra ◽  
Ultraviolet Absorption ◽  
Derivatives Of

ChemInform Abstract: CHARACTERIZATION OF THE ULTRAVIOLET ABSORPTION SPECTRA OF P-SUBSTITUTED DERIVATIVES OF BENZAMIDINE

1976 ◽  
Vol 7 (5) ◽  
Author(s):  
EDYR ROGANA ◽  
DAVID L. NELSON ◽  
MARCOS MARES-GUIA
Keyword(s):  
Absorption Spectra ◽  
Ultraviolet Absorption ◽  
Abstract Characterization ◽  
Derivatives Of
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