Nuclear Magnetic Resonance Coupling Research Articles

Photochemistry of nitroso compounds in solution. XV. Configuration and conformation of the enone oximes obtained from photoaddition of N-nitrosopiperidine to conjugated dienes

In the presence of an acid, N-nitrosopiperidine photolytically adds to conjugated dienes to give 1:1 adducts in excellent yield. While the major products are the syn- and anti-isomers of piperidino α,β-unsaturated oxime derived from 1,4-addition, similar types of oximes derived from 1,2-addition are also obtained. The ratio of syn- and anti-oximes is determined by the relative configurational and the conformational stabilities of the two forms. The nuclear magnetic resonance (n.m.r.) chemical shifts and coupling constants provide useful information for the determination of the configuration and conformation of the oximes. A comparison of the n.m.r. data from α,β-unsaturated oximes indicates that the α-proton generally resonates at a lower field than the β-proton in contrast to the chemical shifts of α,β-unsaturated carbonyl compounds. The photoaddition of nitrosopiperidine to cycloheptatriene gave tropone oxime, probably through the elimination of piperidine from the 1:1 adduct.

Nuclear magnetic resonance coupling constants in tin in 3,3,3-trifluoropropyltin compounds

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTNuclear magnetic resonance coupling constants in tin in 3,3,3-trifluoropropyltin compoundsDwight Edward Williams, Louis H. Toporcer, and Gary M. RonkCite this: J. Phys. Chem. 1970, 74, 10, 2139–2142Publication Date (Print):May 1, 1970Publication History Published online1 May 2002Published inissue 1 May 1970https://doi.org/10.1021/j100909a016RIGHTS & PERMISSIONSArticle Views138Altmetric-Citations11LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (472 KB) Get e-Alerts

Conformation of syn- and anti-3-substituted cis-hexahydrocarbazoles from nuclear magnetic resonance coupling constants

Double-irradiation experiments have been used to interpret the n.m.r. spectra of the methiodides of syn- and anti-3-substituted N-methyl-cis-hexahydrocarbazoles. The Karplus relation and conformational theory have been used qualitatively to rationalise the characteristic splitting patterns and coupling involving the ring junction protons, thus distinguishing between alternative conformations.For the syn-series and the 3,3-dimethyl compound it is suggested that the alicyclic ring adopts a rigid shallow boat conformation. The anti-compounds are probably conformationally mobile at probe temperature.

NMR coupling constants as probes into London-van der Waals interactions

Dispersion forces make small but significant contributions to nuclear magnetic resonance coupling constants. The heteronuclear 117SnCH, 119SnCH, and 207PbCH coupling constants in tetramethyllead and tetramethyltin are very well correlated with the change in the dispersion interaction. Measurements are performed in n-heptane-carbon disulfide mixtures differing markedly in their refractive indices, but not in their dielectric constants. It is thus possible to isolate a contribution to the coupling parameter from London-van der Waals forces by using nonpolar solutes in nonpolar solvents. This contribution appears to be of a similar magnitude to the reaction field and/or Stark terms proposed for polar solutes in polar media. This contribution is to be considered in addition to these terms when the solvent dependencies of coupling constants for polar solutes are being analyzed.

Temperature dependence of nuclear magnetic resonance coupling constants and chemical shifts of the vinyl halides and some vinyl esters

Temperature dependence of nuclear magnetic resonance coupling constants and chemical shifts of the vinyl halides and some vinyl esters

Conformation of the 17-beta side chain of C-20 oxygenated pregnane derivatives as determined by nuclear magnetic resonance coupling CONSTANTS.

Conformation of the 17-beta side chain of C-20 oxygenated pregnane derivatives as determined by nuclear magnetic resonance coupling CONSTANTS.

Nuclear magnetic resonance coupling constant relation-ships in analogous ethyl, disilanyl, silymethyl, and methylsilyl compounds

Nuclear magnetic resonance coupling constant relation-ships in analogous ethyl, disilanyl, silymethyl, and methylsilyl compounds

Nuclear Magnetic Resonance Coupling Constants in Maleic and Itaconic Acids and Their Anhydrides

Nuclear Magnetic Resonance Coupling Constants in Maleic and Itaconic Acids and Their Anhydrides

The Relative Signs of Phosphorus-Proton Nuclear Magnetic Resonance Coupling Constants

Relative signs and magnitudes of proton nuclear magnetic resonance coupling constants in phosphorus compounds

Substituent Effects on Nuclear Magnetic Resonance Coupling Constants and Chemical Shifts in a Saturated System: Hexachlorobicyclo [2.2.1]heptenes

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTSubstituent Effects on Nuclear Magnetic Resonance Coupling Constants and Chemical Shifts in a Saturated System: Hexachlorobicyclo [2.2.1]heptenesKenneth L. WilliamsonCite this: J. Am. Chem. Soc. 1963, 85, 5, 516–519Publication Date (Print):March 1, 1963Publication History Published online1 May 2002Published inissue 1 March 1963https://doi.org/10.1021/ja00888a006RIGHTS & PERMISSIONSArticle Views192Altmetric-Citations156LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (550 KB) Get e-Alerts Get e-Alerts