Nuclear Magnetic Resonance Spectra of Systems of the A3B2C Type: Proton Magnetic Resonance Spectra and the Absolute Signs of the Proton‐Proton Spin Coupling Constants in Ethyl Acetylene and Ethyl Mercaptan

1960 ◽  
Vol 33 (3) ◽  
pp. 727-733 ◽  
Author(s):  
P. T. Narasimhan ◽  
Max T. Rogers
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Proton Magnetic Resonance ◽  
Proton Spin ◽  
Coupling Constants ◽  
Spin Coupling ◽  
Proton Proton ◽  
Nuclear Magnetic Resonance Spectra ◽  
Spin Coupling Constants ◽  
Magnetic Resonance Spectra

THE ANALYSIS OF NUCLEAR MAGNETIC RESONANCE SPECTRA: I. SYSTEMS OF TWO AND THREE NUCLEI

1957 ◽  
Vol 35 (1) ◽  
pp. 67-83 ◽  
Author(s):  
H. J. Bernstein ◽  
J. A. Pople ◽  
W. G. Schneider
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Coupling Constants ◽  
Spin Coupling ◽  
Resonance Signal ◽  
Nuclear Magnetic Resonance Spectra ◽  
Order Of Magnitude ◽  
Spin Coupling Constants ◽  
Magnetic Resonance Spectra ◽  
Nuclear Magnetic

This paper is concerned with the general problem of the interpretation and analysis of nuclear magnetic resonance spectra of systems in which chemical shift and spin-coupling constants are of the same order of magnitude. Only nuclei of spin 1/2 are considered. Detailed methods are developed for:(a) Two chemically non-equivalent nuclei of the same species (written AB),(b) Three nuclei of the same species, two of which are equivalent (written AB2),(c) Three nuclei (ABX), two of which are of the same species (AB) and the third (X) is either a different species or has a resonance signal well separated from A and B.Proton resonance spectra of S-guaiazulene, 2,6-lutidine, and 2,3-lutidine are reported and used as examples of the methods of analysis.

THE ANALYSIS OF NUCLEAR MAGNETIC RESONANCE SPECTRA: III. PYRIDINE AND DEUTERATED PYRIDINES

1957 ◽  
Vol 35 (12) ◽  
pp. 1487-1495 ◽  
Author(s):  
W. G. Schneider ◽  
H. J. Bernstein ◽  
J. A. Pople
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
High Resolution ◽  
Chemical Shifts ◽  
Coupling Constants ◽  
Spin Coupling ◽  
Calculated Spectrum ◽  
Proton Resonance ◽  
Nuclear Magnetic Resonance Spectra ◽  
Spin Coupling Constants

The proton resonance spectra of pyridine, 2,6-pyridine-d2, 3-pyridine-d1, and 4-pyridine-d1 have been obtained for the pure liquids under conditions of high resolution. The spectra have been analyzed as proton groupings of AB2X2, AB2, perturbed ABX, and B2X2 respectively. The spin-coupling constants obtained from analysis of the simpler spectra of the deuterated molecules were used to suggest trial solutions for the analysis of the complicated AB2X2 spectrum of pyridine. A final set of chemical shifts and spin-coupling constants derived for pyridine give satisfactory agreement between the observed and calculated spectrum.

Carbon-13 nuclear magnetic resonance studies of (Z)-5-fluoro-2-methyl-1-{[p-(methylsulfinyl)phenyl] methylene}-1H-indene-3-acetic acid (sulindac) and some related compounds

1978 ◽  
Vol 56 (16) ◽  
pp. 2129-2133 ◽  
Author(s):  
Alan Wilmot Douglas
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Acetic Acid ◽  
Magnetic Resonance ◽  
Nuclear Spin ◽  
Substituent Effects ◽  
Coupling Constants ◽  
Spin Coupling ◽  
Nuclear Magnetic Resonance Spectra ◽  
Spin Coupling Constants ◽  
Nuclear Magnetic

Carbon-13 nuclear magnetic resonance spectra have been obtained and fully assignee for a number of 2-methyl-1-{[p-(methylthio) or -(methylsulfinyl}phenyl]methylene}-1H-indene-3- acetic acid derivatives, including the potent anti-inflammatory compound sulindac, 1Z. Paired E and Z isomers were studied along with the sulindac sodium salt and ethyl ester in the Z series. Variations in steric crowding in E vs. Z isomers produce chemical shift effects which alternate with the number of intervening bonds. Fluorine substituent effects and 19F nuclear spin coupling to 13C nuclei, second-order features in off-resonance proton-decoupled spectra, and values of long-range 13CH nuclear spin coupling constants have been employed in making a complete set of assignments.

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.

THE PROTON MAGNETIC RESONANCE SPECTRA OF CHRYSANTHEMUM ETHYL ESTER AND THE RELATED cis- AND trans-CHRYSANTHEMUMIC ACIDS

1962 ◽  
Vol 40 (5) ◽  
pp. 875-881 ◽  
Author(s):  
H. M. Hutton ◽  
T. Schaefer
Keyword(s):  
Magnetic Resonance ◽  
Ethyl Ester ◽  
Proton Magnetic Resonance ◽  
Acid Ethyl Ester ◽  
Proton Spin ◽  
Coupling Constants ◽  
Spin Coupling ◽  
Cis And Trans Isomers ◽  
Cis And Trans ◽  
Magnetic Resonance Spectra

The high-resolution proton magnetic resonance spectra of a mixture of the cis and trans isomers of chrysanthemum monocarboxylic acid ethyl ester have been studied. The cis-chrysanthemumic and trans-chrysanthemumic acids spectra were obtained to facilitate the interpretation of the complex spectra of the ester. The percentage of the trans isomer in the chrysanthemum ester was measured to be 62.0 ± 1.1%. The cyclopropane proton spin coupling constants were found to be Jcis = 8.7 c.p.s. and Jtrans = 5.4 c.p.s., in reasonable agreement with Karplus' calculations of the dependence of coupling constants on the dihedral angle.

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