PHOTOCHEMICAL INTERCHANGE OF HALOGENS IN AROMATIC COMPOUNDS. II. TEMPERATURE DEPENDENCE OF SOME SUBSTITUENT EFFECTS

1962 ◽  
Vol 66 (11) ◽  
pp. 2118-2120 ◽  
Author(s):  
Barton Milligan ◽  
Ronald L. Bradow

1969 ◽  
Vol 24 (11) ◽  
pp. 1365-1370 ◽  
Author(s):  
H.-H. Perkampus ◽  
U. Krüger ◽  
W. Krüger

The proton chemical shifts of aromatic compounds are strongly concentration dependent. Moreever, for molecules with a dipole moment a temperature dependence of the proton chemical shifts is observed. For hemellitone, p-methylanisole, o-chlortoluene, p-chlortoluene, pyrrole and N-methyl-pyrrole the enthalpies of a dipole-dipole association between -0,7 and -1,8 Kcal could be estimated by NMR measurements combined with the temperature dependence in the whole range of the molefraction (0 → 1).



1969 ◽  
Vol 47 (24) ◽  
pp. 4577-4588 ◽  
Author(s):  
G. E. Dunn ◽  
R. S. McDonald

Infrared spectra in the frequency region 1300–1760 cm−1 are reported for 41 substituted sodium benzoates and 10 substituted sodium salicylates in deuterium oxide solution, and for 9 substituted salicylic acids in chloroform and carbon tetrachloride solutions. Carboxylate stretching frequencies of benzoates and salicylates correlate poorly with substituent constants, but the asymmetric frequencies of benzoates and salicylates correlate well with each other, and the asymmetric frequencies of benzoates correlate well with the asymmetric frequencies of the corresponding nitrobenzenes. It is suggested that, among substituted aromatic compounds, group vibrations which couple with the ring vibrations may correlate well with similar vibrations of other groups, but not with coupled vibrations of different symmetry, uncoupled vibrations, or substituent constants. Chelation in chloroform solutions of salicylic acid dimers can be detected by its influence on substituent effects, but infrared spectra provide no good evidence for chelation in aqueous sodium salicylates.



2012 ◽  
Vol 55 (2) ◽  
pp. 236-239
Author(s):  
N. V. Zhdanova ◽  
M. I. Deryabin ◽  
V. V. Solodunov


1991 ◽  
Vol 46 (4) ◽  
pp. 304-306 ◽  
Author(s):  
Z. Gryczyński ◽  
A. Kawski

Abstract The effect of 2-substitutions (NH2 . O, CH3O, CI. Br) in 3-methylquinoxalines on the fluorescence and phosphorescence band position and intensity at 293 K, and the temperature dependence of their fluorescence and phosphorescence quantum yields were investigated in polyvinyl alcohol) films



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