The Near Ultraviolet Absorption Spectra of Some Fluorinated Derivatives of Methane and Ethylene1,2

1950 ◽  
Vol 72 (12) ◽  
pp. 5486-5489 ◽  
Author(s):  
J. R. Lacher ◽  
L. E. Hummel ◽  
E. F. Bohmfalk ◽  
J. D. Park
1961 ◽  
Vol 39 (1) ◽  
pp. 171-179 ◽  
Author(s):  
C. N. R. Rao ◽  
J. Ramachandran ◽  
A. Balasubramanian

The near-ultraviolet absorption spectra of polyphenyl derivatives of the IVb and Vb elements have been studied in detail. In the case of the triphenyl derivatives of the Vb elements, the unshared p-electrons on the central atoms interact strongly with the π-orbitals of the benzene rings. When the central atoms do not possess unshared electrons as in the case of the derivatives of the IVb and the pentavalent Vb elements, there appears to be no such resonance interaction. The Hammett reactivity constants of the para- and meta-trityl, triphenylsilyl, and triphenylgermanyl groups are estimated to be close to zero. However, the reactivity constant of the triphenylsilyl group in the para position of phenol is estimated to be about 0.30. The infrared spectra of the phenyl derivatives of the IVb and Vb elements show smooth trends due to mass effects of the central atoms, in the C=C skeletal, C—H out-of-plane, and other vibrations. The absorption frequencies which are assigned to the phosphorus-phenyl and silicon–phenyl bonds in the literature do not appear to be unique for these linkages.


1969 ◽  
Vol 47 (21) ◽  
pp. 4076-4083 ◽  
Author(s):  
H. L. Holmes ◽  
D. J. Currie

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.


1949 ◽  
Vol 27b (5) ◽  
pp. 437-461 ◽  
Author(s):  
Y. Hirshberg ◽  
R. Norman Jones

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.


1969 ◽  
Vol 47 (17) ◽  
pp. 3278-3280 ◽  
Author(s):  
A. D. Delaney ◽  
D. J. Currie ◽  
H. L. Holmes

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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