Proton chemical shifts in NMR. Part 13.1 Proton chemical shifts in ketones and the magnetic anisotropy and electric field effect of the carbonyl group

1999 ◽  
pp. 441-448 ◽  
Author(s):  
Raymond J. Abraham ◽  
Nick J. Ainger
Keyword(s):  
Electric Field ◽  
Magnetic Anisotropy ◽  
Carbonyl Group ◽  
Field Effect ◽  
Chemical Shifts ◽  
Electric Field Effect ◽  
Proton Chemical Shifts

Evidence for the existence of an electric field effect from the vinyl proton magnetic resonance spectra of 4-substituted styrenes

1968 ◽  
Vol 46 (24) ◽  
pp. 3813-3820 ◽  
Author(s):  
G. K. Hamer ◽  
W. F. Reynolds
Keyword(s):  
Chemical Shift ◽  
Electric Field ◽  
Field Effect ◽  
Chemical Shifts ◽  
Electric Field Effect ◽  
Vinyl Proton ◽  
Concentration Effects ◽  
Electric Field Effects ◽  
Field Effects ◽  
Proton Chemical Shifts

Vinyl proton chemical shifts of styrene and six 4-substituted styrenes have been determined at infinite dilution in cyclohexane. It is shown that changes in the chemical shift difference of the β protons, Δ(δC − δB) can be accounted for by electric field effects. Reasonable values of the constant in the Buckingham equation of(−3.11 ± 0.50) × 10−12 and (−4.77 ± 0.83) × 10−12 are obtained from two different types of field effect calculations. Residual chemical shift changes for β protons after correction for electric field effects can be explained in terms of mesomeric and possibly inductive mechanisms. α-Proton chemical shift values cannot be satisfactorily rationalized. Small concentration effects are noted, usually resulting in high field shifts with increasing concentration. Previous results are reexamined in order to resolve a conflict in the literature.

Electric-field effect on magnetic anisotropy of MgO/CoFe/capping structures

2019 ◽  
Vol 126 (15) ◽  
pp. 153902 ◽  
Author(s):  
Minggang Zeng ◽  
James Lourembam ◽  
Sze Ter Lim
Keyword(s):  
Electric Field ◽  
Magnetic Anisotropy ◽  
Field Effect ◽  
Electric Field Effect

Substituent-induced 1H chemical shifts for 4-substituted (2, 2-dichlorocyclopropyl)benzenes: further evidence for intramolecular electric field effects on 1H chemical shifts

1977 ◽  
Vol 55 (3) ◽  
pp. 530-535 ◽  
Author(s):  
Robert H. Kohler ◽  
William F. Reynolds
Keyword(s):  
Electric Field ◽  
Field Effect ◽  
Ring Current ◽  
Chemical Shifts ◽  
Basic Pattern ◽  
Electric Field Effects ◽  
Field Effects ◽  
The Individual ◽  
Induced Changes ◽  
Proton Chemical Shifts

Correlations of cyclopropyl proton chemical shifts for 4-substituted (2,2-dichlorocyclopropyl)-benzenes with σI and σR0 provide evidence that these chemical shifts reflect direct field effects and weak phenyl–cyclopropyl conjugative interactions. Corrections for variable ring current effects due to substituent-induced changes in conformation improve the individual correlations but do not alter the basic pattern of results. Correlation of the β cyclopropyl 1H chemical shift difference with σI with calculated hydrogen electron densities, and with calculated electric field components provides further strong evidence for a field effect on 1H chemical shifts.

scholarly journals Possible origin of nonlinear magnetic anisotropy variation in electric field effect in a double interface system

2014 ◽  
Vol 7 (11) ◽  
pp. 113005 ◽  
Author(s):  
Daiki Yoshikawa ◽  
Masao Obata ◽  
Yusaku Taguchi ◽  
Shinya Haraguchi ◽  
Tatsuki Oda
Keyword(s):  
Electric Field ◽  
Magnetic Anisotropy ◽  
Field Effect ◽  
Electric Field Effect ◽  
Interface System

1.3-Dithienium-and 1.3-Dithiolenium Salts, VI ,13C NMR Spectroscopic Investigations on 2-Substituted 1,3-Dithian-2-ylium Cations. Unusual γ-Effects

1997 ◽  
Vol 52 (6) ◽  
pp. 757-761 ◽  
Author(s):  
Hans-Otto Kalinowski ◽  
Ingfried Stahl
Keyword(s):  
Electric Field ◽  
Density Distribution ◽  
13C Nmr ◽  
Field Effect ◽  
Electron Density Distribution ◽  
Chemical Shifts ◽  
Membered Ring ◽  
Electric Field Effect ◽  
Polarisation Effect ◽  
C Nmr

Abstract The 13C NMR chemical shifts of 19 2-substituted 1,3-dithian-2-ylium-tetrafluorborates 1a-1s are discussed in comparison to known analogous 1,3-dithianes and 2-lithio-1,3-dithianes. The unusual γ-effects (up to 9 ppm), which can also observed in other six-membered ring systems, are explained by the electric field effect (σ-polarisation effect). The electron density distribution can be estimated qualitatively by comparison with the 1,3-dioxan-2-ylium-and cyclohexylcations.

Chemical Shift. VI. The Long-range Shielding Effects of Ethylene–Ketal and −Thioketal Groups

1971 ◽  
Vol 49 (9) ◽  
pp. 1335-1338 ◽  
Author(s):  
J. W. ApSimon ◽  
H. Beierbeck ◽  
D. K. Todd ◽  
P. V. Demarco ◽  
W. G. Craig
Keyword(s):  
Chemical Shift ◽  
Electric Field ◽  
Long Range ◽  
Field Effect ◽  
Chemical Shifts ◽  
Electric Field Effect ◽  
Electric Dipoles ◽  
Derivatives Of ◽  
Shielding Effects

The calculation of chemical shift values by the method used in parts I–V (1–5) has been extended to a derivation of the shielding effects of the ethylene–ketal and −thioketal groups. For these studies ketal and thioketal derivatives of monoketoandrostanes were prepared. The chemical shifts of the C-18 and -19 methyl protons in these compounds are reported for the solvents CDCl3, CCl4 and benzene.Representing both groups by point dipoles, values for the anisotropies and for K, a parameter descriptive of the electric field effect, were derived for various, coincidental, locations of the magnetic and electric dipoles along the symmetry axes of the two groups.

scholarly journals Nonlinear electric field effect on perpendicular magnetic anisotropy in Fe/MgO interfaces

2017 ◽  
Vol 50 (40) ◽  
pp. 40LT04 ◽  
Author(s):  
Qingyi Xiang ◽  
Zhenchao Wen ◽  
Hiroaki Sukegawa ◽  
Shinya Kasai ◽  
Takeshi Seki ◽  
...  
Keyword(s):  
Electric Field ◽  
Magnetic Anisotropy ◽  
Field Effect ◽  
Perpendicular Magnetic Anisotropy ◽  
Electric Field Effect
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