NUCLEAR MAGNETIC RESONANCE STUDIES: PART I. THE CHEMICAL SHIFT OF THE FORMYL PROTON IN AROMATIC ALDEHYDES

1962 ◽  
Vol 40 (6) ◽  
pp. 1071-1081 ◽  
Author(s):  
R. E. Klinck ◽  
J. B. Stothers
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Chemical Shift ◽  
Solvent Effects ◽  
Aromatic Aldehydes ◽  
Lower Field ◽  
Magnetic Resonance Studies ◽  
Chemical Shift Data ◽  
Steric Inhibition Of Resonance ◽  
Shift Data

Chemical shift data for the formyl proton in some 30 aromatic aldehydes are reported. It was found that meta- and para-substituted benzaldehydes exhibited this peak in the range 9.65–10.20 δ, while ortho-substituted compounds appear at lower field, 10.20–10.50 δ; the former shifts show an approximate correlation with the Hammett sigma parameter. Evidence for steric inhibition of resonance is presented for some ortho-substituted compounds and some interesting solvent effects are discussed.

Metabolites of bird's nest fungi. Part 10. Carbon-13 nuclear magnetic resonance studies on the cyathins

1978 ◽  
Vol 56 (16) ◽  
pp. 2197-2199 ◽  
Author(s):  
William A. Ayer ◽  
Thomas T. Nakashima ◽  
Dale E. Ward
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Chemical Shift ◽  
Chemical Shifts ◽  
Magnetic Resonance Studies ◽  
Chemical Shift Data ◽  
Related Compounds ◽  
Shift Data ◽  
Methyl Acetal ◽  
Magnetic Resonance Spectra

The carbon-13 magnetic resonance spectra of cyathin A3 and several related compounds have been measured and the chemical shifts have been assigned. The chemical shift data have been used to determine the stereochemistry at C-1 in cyafrin A4 and to determine the position of the bromine in 1-bromoallocyathin A3 methyl acetal.

Nuclear magnetic resonance spectra, stereochemistry, and conformation of flavan derivatives

1964 ◽  
Vol 17 (6) ◽  
pp. 632 ◽  
Author(s):  
JW Clark-Lewis ◽  
LM Jackman ◽  
TM Spotswood
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Chemical Shift ◽  
Heterocyclic Ring ◽  
Coupling Constant ◽  
Nuclear Magnetic Resonance Spectra ◽  
Chemical Shift Data ◽  
Shift Data ◽  
Magnetic Resonance Spectra ◽  
Nuclear Magnetic

Chemical-shift and coupling-constant data for protons in 68 flavan derivatives are reported. Coupling-constant data for interactions involving the 2-, 3-, and 4-protons have been used to define the configuration of the 2-, 3-, and 4-substituents and the conformation of the heterocyclic ring. It is shown that chemical-shift data for protons of the heterocyclic ring and of 3- and 4-acetoxyl groups are of little value in stereochemical studies. Analysis of the absorptions of the aromatic protons shows that N.M.R. is useful for determining the oxygenation pattern in rings A and B.

Determination of for aliphatic ketones from nuclear magnetic resonance chemical shift data

1970 ◽  
Vol 48 (12) ◽  
pp. 1919-1923 ◽  
Author(s):  
Donald G. Lee
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Raman Spectroscopy ◽  
Magnetic Resonance ◽  
Chemical Shift ◽  
Aliphatic Ketones ◽  
Chemical Shift Data ◽  
Shift Data ◽  
Good Agreement ◽  
Nuclear Magnetic

The [Formula: see text] values for 3-pentanone, 2-butanone, and 3-methyl-2-butanone have been determined from chemical shift data. The values (−7.6, −7.1, and −7.2, respectively) are in good agreement with those previously determined for aliphatic ketones by use of ultraviolet–visible and Raman spectroscopy.

17O nuclear magnetic resonance spectroscopic study of substituted phthalic anhydrides and phthalides

1987 ◽  
Vol 65 (6) ◽  
pp. 1214-1217 ◽  
Author(s):  
David W. Boykin ◽  
Alfons L. Baumstark ◽  
Margaret M. Kayser ◽  
Chantal M. Soucy
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Chemical Shift ◽  
Chemical Shifts ◽  
Carbonyl Groups ◽  
Chemical Shift Data ◽  
The Relationship ◽  
Electronic Character ◽  
Shift Data ◽  
Phthalic Anhydrides

17O chemical shift data (natural abundance) for 3-substituted phthalic anhydrides and 4- and 7-substituted phthalides in acetonitrile at 75 °C are reported. Steric interactions of substituents ortho to the carbonyl groups result in deshielding effects (9–22 ppm) relative to parent compounds regardless of the electronic character of the substituents. Factors contributing to the deshielding effects are discussed. The relationship between 17O chemical shifts and regiochemistry of the phthalic anhydrides is discussed.

IR and NMR Correlations for 3-x and 4-x Substituted Anilines

1993 ◽  
Vol 47 (4) ◽  
pp. 411-422 ◽  
Author(s):  
R. A. Nyquist
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Carbon Tetrachloride ◽  
Magnetic Resonance ◽  
Chemical Shift ◽  
Vapor Phase ◽  
Reference Frequency ◽  
Substituted Anilines ◽  
Nmr Chemical Shift ◽  
Chemical Shift Data ◽  
Shift Data

Infrared (IR) and/or Nuclear Magnetic Resonance (NMR) carbon-13 data are presented for 3- x and 4- x substituted anilines. Correlations are presented for the δ13C-1 chemical shift vs. Hammett δ p and δ m values, vasym., NH2 vs. δ13C-1, vsym. NH2 vs. δ13C-1, δ13C-1 vs. vasym. NH2, δ13C-1 vs. the absorbance ratio A( vasym. NH2/ A( vsym. NH2), and δ13C-l vs. Taft δ R°. The IR data for these compounds are recorded in the vapor phase, and in hexane, carbon tetrachloride, and chloroform solutions. The NMR chemical shift data for these compounds in solution with chloroform were obtained with the use of tetramethylsilane as the δ13C resonance reference frequency.

scholarly journals Proton and carbon-13 nuclear magnetic resonance chemical shift data for nitroquinolines and their N-oxides.

1986 ◽  
Vol 34 (2) ◽  
pp. 881-885 ◽  
Author(s):  
TOYO KAIYA ◽  
NAOHIRO SHIRAI ◽  
YUTAKA KAWAZOE
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Chemical Shift ◽  
Chemical Shift Data ◽  
Shift Data ◽  
Nuclear Magnetic

Carbon-13 Nuclear Magnetic Resonance Spectra of Isothiazole, 1,2-Dithiole, and 1,3-Dithiole Derivatives

1975 ◽  
Vol 53 (6) ◽  
pp. 836-844 ◽  
Author(s):  
N. Plavac ◽  
I. W. J. Still ◽  
M. S. Chauhan ◽  
D. M. McKinnon
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Chemical Shift ◽  
Carbonyl Compounds ◽  
Heterocyclic Compounds ◽  
Chemical Shifts ◽  
Conjugated Systems ◽  
Nuclear Magnetic Resonance Spectra ◽  
Chemical Shift Data ◽  
Shift Data

Carbon-13 chemical shift data have been obtained for a number of isothiazole, benzo[c]isothiazole, 1,2-dithiole, and 1,3-dithiole derivatives. A number of these compounds are thiones and the chemical shifts of the C=S carbons are discussed in the light of recent attempts to predict such chemical shifts from those of the analogous carbonyl compounds. Comparisons of substituent chemical shift (s.c.s.) effects in these heterocyclic compounds with those in simpler aromatic or conjugated systems have been made and additivity correlations tested in a number of cases.

Organometallic compounds in synthesis. VIII. Carbon-13 nuclear magnetic resonance spectroscopic study of tricarbonylcyclohexadienyliron salts

1976 ◽  
Vol 29 (8) ◽  
pp. 1671 ◽  
Author(s):  
AJ Birch ◽  
PW Westerman ◽  
AJ Pearson
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Chemical Shift ◽  
Spectroscopic Study ◽  
Chemical Shifts ◽  
Substituent Effects ◽  
Organometallic Compounds ◽  
Nucleophilic Attack ◽  
Chemical Shift Data ◽  
Shift Data

The carbon-13 N.M.R. spectra of eleven substituted tricarbonylcyclohexadienyliron salts (1) have been determined and individual resonances assigned. Substituent effects have been deduced and compared with corresponding effects in cyclohexadienyl cations. The structures of the tricarbonylcyclohexadienyliron salts are discussed with reference to chemical shift data. The proportions of irreversible nucleophilic attack at the terminal positions in the unsymmetrical 2-substituted salts are compared with the observed chemical shifts at these carbon atoms.

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