Substituent-induced chemical shifts and coupling constants in phosphorus-31 nuclear magnetic resonance spectra of ethyl .alpha.-diethylphosphonocinnamates and .alpha.-diethylphosphonocinnamonitriles

1987 ◽  
Vol 52 (10) ◽  
pp. 2011-2015 ◽  
Author(s):  
Charles N. Robinson ◽  
Carl D. Slater
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Chemical Shifts ◽  
Coupling Constants ◽  
Nuclear Magnetic Resonance Spectra ◽  
Magnetic Resonance Spectra ◽  
Nuclear Magnetic

scholarly journals Carbon-13 nuclear magnetic resonance spectra of oxazoles

1979 ◽  
Vol 57 (23) ◽  
pp. 3168-3170 ◽  
Author(s):  
Henk Hiemstra ◽  
Hendrik A. Houwing ◽  
Okko Possel ◽  
Albert M. van Leusen
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Nmr Spectra ◽  
Chemical Shifts ◽  
Coupling Constants ◽  
Proton Coupling ◽  
Nuclear Magnetic Resonance Spectra ◽  
C Nmr ◽  
Magnetic Resonance Spectra ◽  
Nuclear Magnetic

The 13C nmr spectra of oxazole and eight mono- and disubstituted derivatives have been analyzed with regard to the chemical shifts and the various carbon–proton coupling constants of the ring carbons. The data of the parent oxazole are compared with thiazole and 1-methylimidazole.

13C nuclear magnetic resonance spectra of 3,6-disubstituted pyridazines

1991 ◽  
Vol 69 (6) ◽  
pp. 972-977 ◽  
Author(s):  
Gottfried Heinisch ◽  
Wolfgang Holzer
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Chemical Shifts ◽  
Coupling Constants ◽  
Spin Coupling ◽  
Molecular Orbital Calculations ◽  
Nuclear Magnetic Resonance Spectra ◽  
13C Nuclear Magnetic Resonance ◽  
Magnetic Resonance Spectra ◽  
Nuclear Magnetic

The 13C nuclear magnetic resonance spectra of 17 3,6-disubstituted pyridazine derivatives have been systematically analyzed. Chemical shifts and various 13C, 1H coupling constants are reported. Attempts were made to correlate these data with results obtained from semiempirical molecular orbital calculations as well as with substituent electronegativities and Taft's substituent constants σI and σR0. Key words: 3,6-disubstituted pyridazines, 13C NMR spectroscopy, 13C, 1H spin coupling constants.

Flavan derivatives. XXI. Nuclear magnetic resonance spectra, configuration, and conformation of flavan derivatives

1968 ◽  
Vol 21 (8) ◽  
pp. 2059 ◽  
Author(s):  
JW Clark-Lewis
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Chemical Shifts ◽  
Heterocyclic Ring ◽  
Coupling Constants ◽  
Vicinal Coupling Constants ◽  
Nuclear Magnetic Resonance Spectra ◽  
Configuration And Conformation ◽  
Magnetic Resonance Spectra ◽  
Nuclear Magnetic

Nuclear magnetic resonance spectra of 80 compounds belonging to several classes of flavan derivative have been analysed, and chemical shifts and coupling constants of heterocyclic ring protons and aromatic protons are tabulated and discussed. Compounds examined include flav-2-enes, flav-3-enes, 3-substituted flavanones and flavans, 2- and 4-substituted isoflavans, 3,4-disubstituted flavans, and flavan-4-ols. The geometrical configurations of substituents in the heterocyclic ring follow unequivocally from the magnitudes of the vicinal coupling constants.

The 19F nuclear magnetic resonance spectra of antimony pentafluoride, cis-Sb3F16− and higher polyanions SbnF5n+1−

1970 ◽  
Vol 48 (21) ◽  
pp. 3413-3424 ◽  
Author(s):  
J. Bacon ◽  
P. A. W. Dean ◽  
R. J. Gillespie
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Fine Structure ◽  
Magnetic Resonance ◽  
Chemical Shifts ◽  
Coupling Constants ◽  
Antimony Pentafluoride ◽  
Nuclear Magnetic Resonance Spectra ◽  
Magnetic Resonance Spectra ◽  
Nuclear Magnetic

The resonances in the 19F nuclear magnetic resonance (n.m.r.), spectrum of antimony pentafluoride have been reassigned and it is shown that the fine structure observed in the spectrum of antimony pentafluoride in various inert solvents can only be explained by considering the effects of magnetic nonequivalence. Solutions of t-butyl fluoride and tetra-n-butylammonium hexafluoroantimonate in excess SbF5/SO2ClF are shown to contain the Sb3F16− and Sb4F21− anions which have cis-fluorine bridged structures. The coupling constants and chemical shifts in the n.m.r. spectra of Sb3F16−, Sb4F21−, (SbF5)n and 1:1 and 2:1 complexes of SbF5 are compared and discussed.

Nuclear magnetic resonance spectra of pyrrolizidine alkaloids. I. The spectra of retronecine and heliotridine

1965 ◽  
Vol 18 (10) ◽  
pp. 1605 ◽  
Author(s):  
CCJ Culvenor ◽  
ML Heffernen ◽  
WG Woods
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Chemical Shift ◽  
Detailed Analysis ◽  
Pyrrolizidine Alkaloids ◽  
Chemical Shifts ◽  
Coupling Constants ◽  
Nuclear Magnetic Resonance Spectra ◽  
Magnetic Resonance Spectra ◽  
Nuclear Magnetic

The chemical shifts and coupling constants of the protons in retronecine and heliotridine are derived by detailed analysis of the nuclear magnetic resonance spectra of these compounds. The factors which influence the appearance and ease of interpretation of spectra of pyrrolizidine derivatives, principally the chemical shift difference of the H 6 protons and conformational averaging, are discussed. The conformations of retronecine and heliotridine are discussed in relation to their coupling constants; the former compound is exo-buckled whereas the latter is a mixture of rapidly interconverting exo- and endo-buckled forms.

Fluorine and Proton Nuclear Magnetic Resonance Spectra of N-Dialkylaminosulfur Trifluorides

1972 ◽  
Vol 50 (15) ◽  
pp. 2428-2431 ◽  
Author(s):  
D. G. Ibbott ◽  
A. F. Janzen
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Chemical Shifts ◽  
Coupling Constants ◽  
Proton Nuclear Magnetic Resonance ◽  
Nuclear Magnetic Resonance Spectra ◽  
Magnetic Resonance Spectra ◽  
Nuclear Magnetic

The fluorine and proton n.m.r. spectra of N-dimethylaminosulfur trifluoride and N-diethylaminosulfur trifluoride have been recorded under anhydrous conditions at −68 and +22°. Chemical shifts and coupling constants of axial and equatorial fluorines are reported.

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