Polar field effects on fluorine-19 chemical shifts. Important effect

Significant 1H upfield chemical shifts of the guests in the capsules are consequences of polarizability of chalcogens, electric field effects and peripheral chains. The effects of the electric field and of magnetic field are of equal importance.

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

Canadian Journal of Chemistry ◽

10.1139/v77-073 ◽

1977 ◽

Vol 55 (3) ◽

pp. 530-535 ◽

Cited By ~ 5

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.

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ChemInform Abstract: ELECTRONIC EFFECT OF THE TRICYANOMETHYL GROUP BY CARBON-13 AND FLUORINE-19 NMR: NATURE OF ARYL FLUORINE-19 NMR POLAR FIELD EFFECTS IN THE BENZENE AN NAPHTHALENE RING SYSTEMS

Chemischer Informationsdienst ◽

10.1002/chin.197951058 ◽

1979 ◽

Vol 10 (51) ◽

Author(s):

W. ADCOCK ◽

D. P. COX

Keyword(s):

Electronic Effect ◽

Polar Field ◽

Naphthalene Ring ◽

Ring Systems ◽

Field Effects

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Substituent effects by 19F nuclear magnetic resonance: Polar and π-electron effects

Australian Journal of Chemistry ◽

10.1071/ch9762571 ◽

1976 ◽

Vol 29 (12) ◽

pp. 2571 ◽

Cited By ~ 7

Author(s):

W Adcock ◽

BD Gupta ◽

T Khor

Keyword(s):

Nuclear Magnetic Resonance ◽

Magnetic Resonance ◽

Electrostatic Field ◽

Chemical Shifts ◽

Substituent Effects ◽

Important Conclusion ◽

Field Effects ◽

Electron Distributions ◽

Electron Effects ◽

Nuclear Magnetic

A number of model substituted bicyclic aryl fluorides, including three new fluorobenzocycloalkenes, have been synthesized and their fluorine- 19 spectra measured. An analysis of the data leads to the important conclusion that electrostatic-field effects play an important role in determining aryl 19F chemical shifts. Further the relative π-electron distributions of several benzocycloalkenes are indicated.

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