Structural effects in solvolytic reactions. 18. Relative electron releasing properties of methyl, phenyl, and cyclopropyl groups to the electron deficient center as indicated by solvolysis. Study of carbon-13 chemical shifts as a basis for establishing the electron densities in carbonium ions

1977 ◽  
Vol 99 (6) ◽  
pp. 1712-1716 ◽  
Author(s):  
Herbert C. Brown ◽  
Edward N. Peters
Keyword(s):  
Chemical Shifts ◽  
Structural Effects ◽  
Electron Densities ◽  
Carbonium Ions ◽  
Relative Electron ◽  
Methyl Phenyl

Correlation of lithium-7 chemical shifts of organolithium derivatives with structural effects

1974 ◽  
Vol 96 (19) ◽  
pp. 6055-6059 ◽  
Author(s):  
Paul A. Scherr ◽  
Robert J. Hogan ◽  
John P. Oliver
Keyword(s):  
Chemical Shifts ◽  
Structural Effects

Correlation of the chemical shifts with ?-electron densities in mono-derivatives of benzene, pyridine, and pyrazine

1968 ◽  
Vol 17 (5) ◽  
pp. 951-958
Author(s):  
G. G. Dvoryantseva ◽  
V. P. Lezina ◽  
V. F. Bystrov ◽  
T. N. Ul'yanova ◽  
G. P. Syrova ◽  
...  
Keyword(s):  
Chemical Shifts ◽  
Electron Densities ◽  
Derivatives Of

Elektronendichte und chemische Verschiebung der Styryldiazin- und Diazaphenanthrenprotonen / Electrondensity and Proton Chemical Shift of Styryldiazines and Diazaphenanthrenes

1972 ◽  
Vol 27 (2) ◽  
pp. 310-319
Author(s):  
H.-H. Perkampus ◽  
Th. Bluhm ◽  
J. Knop
Keyword(s):  
Ring Current ◽  
Chemical Shifts ◽  
Lone Pair ◽  
Current Effect ◽  
Electron Densities ◽  
Paramagnetic Effect ◽  
Nitrogen Lone Pair ◽  
Chemische Verschiebung ◽  
Lone Pair Electrons ◽  
Proton Chemical Shifts

AbstractProton chemical shifts in styryldiazines and diazaphenanthrenes linearly correlate with SCF-π-electron densities of the attached carbon atom and with the electron densities of the hydrogen atom (calculated by the CNDO/2 method). The observed deviations from linearity are discussed in terms of ring current effect, steric effects and the paramagnetic effect of the nitrogen lone pair electrons. An appreciable weakening of ring current is found for diazaphenanthrenes with two adjacent N-atoms. Under the same condition the paramagnetic effect on ortho-hydrogens is increased.

Calcul des déplacements chimiques par la méthode des perturbations finies au niveau INDO avec GIAO et approximation de London. I. 13C et 1H

1982 ◽  
Vol 60 (8) ◽  
pp. 957-969 ◽  
Author(s):  
E. Vauthier ◽  
S. Odiot ◽  
F. Tonnard
Keyword(s):  
Perturbation Method ◽  
Chemical Shifts ◽  
Average Precision ◽  
Electron Densities ◽  
Screening Constant ◽  
First Order ◽  
Finite Perturbation

A formalism for the calculation of σ in the finite perturbation method is developed by keeping hermitian the first order perturbed matrix in B. The σ formalism is separated into mono, di, and triatomic terms, and the importance of the electron densities of neighboring and remote bonds is shown. 13C chemical shifts depend only slightly on the remote bonds in contrast to those for 1H. A calculation of the screening constant for a series of 16 sp and sp2 carbons gives an average precision of 5 ppm for the 13C nuclei. [Journal Translation]

Generation of a Steady-State Overdense Plasma by Microwaves near the Dipole Resonance of a Coaxial Discharge Device

1979 ◽  
Vol 34 (4) ◽  
pp. 423-429 ◽  
Author(s):  
B. Kampmann
Keyword(s):  
Plasma Waveguide ◽  
Electron Densities ◽  
Density Profiles ◽  
System A ◽  
Dipole Resonance ◽  
Relative Electron Density ◽  
Relative Electron ◽  
Waveguide System ◽  
Electron Density Profiles ◽  
Overdense Plasma

At electron densities above the dipole resonance of a coaxial plasma-waveguide-system a steadystate discharge has been generated. The measured complex wave vector is compared to the calculated electromagnetic dispersion relation and allows conclusions concerning electron densities as well as relative electron density profiles. Attention is paid to the occurrence of parametric decay

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