Proton magnetic resonance studies of non-alternant hydrocarbons. I. Some comments on the aromatic character of the fulvenes

1966 ◽  
Vol 19 (10) ◽  
pp. 1813 ◽  
Author(s):  
ML Heffernan ◽  
AJ Jones
Keyword(s):  
Magnetic Resonance ◽  
High Resolution ◽  
Long Range ◽  
Proton Magnetic Resonance ◽  
Coupling Constants ◽  
Magnetic Resonance Studies ◽  
Aromatic Character ◽  
Alternant Hydrocarbons ◽  
Cyclic Dienes ◽  
Magnetic Resonance Spectra

The high-resolution proton magnetic resonance spectra of 6- phenylfulvene, 6-methyl-6-phenylfulvene, and 6-dimethylaminofulvene have been studied in detail. The aromatic character of the fulvenes is discussed in terms of the derived parameters, and observations, in general, indicate that these compounds should be regarded as cyclic dienes. Long-range coupling constants involving protons separated by five and six bonds have been observed.

Protonenresonanz-Spektroskopie ungesättigter Ringsysteme I

1965 ◽  
Vol 20 (10) ◽  
pp. 948-956 ◽  
Author(s):  
Harald Günther
Keyword(s):  
Magnetic Resonance ◽  
Concentration Dependence ◽  
Proton Magnetic Resonance ◽  
Chemical Shifts ◽  
Electron System ◽  
Coupling Constants ◽  
Resonance Signal ◽  
Aromatic Character ◽  
Additional Support ◽  
Magnetic Resonance Spectra

The proton magnetic resonance spectra of 1.6-methano- and 1.6-oxido-cyclodecapentaene are described and analyzed in terms of chemical shifts and coupling constants. The results are discussed in connection with the structure and possible aromatic character of these compounds. Measurements of the concentration dependence of the chloroform resonance signal in solutions of both compounds give additional support for the presence of a delocalized 10 π-electron system.

The analysis of the proton magnetic resonance spectra of heteroaromatic systems. V. Diazanaphthalenes

1965 ◽  
Vol 18 (5) ◽  
pp. 707 ◽  
Author(s):  
PJ Black ◽  
ML Heffernan
Keyword(s):  
Carbon Tetrachloride ◽  
Magnetic Resonance ◽  
Long Range ◽  
Iterative Procedure ◽  
Proton Magnetic Resonance ◽  
Chemical Shifts ◽  
Direct Calculation ◽  
Coupling Constants ◽  
Dilute Solutions ◽  
Magnetic Resonance Spectra

The proton magnetic resonance spectra of the four isomeric diazanaphthalenes, quinoxaline, phthalazine, quinazoline, and cinnoline, all as dilute solutions in carbon tetrachloride and acetone, have been investigated at 100 Mc/s. The chemical shifts and coupling constants have been obtained by direct calculation or, where appropriate, by an iterative procedure. Long-range coupling constants between protons separated by five and six bonds have been observed.

Proton magnetic resonance spectra of indolizine and its methyl derivatives and aza analogues

1964 ◽  
Vol 17 (10) ◽  
pp. 1128 ◽  
Author(s):  
PJ Black ◽  
ML Heffernan ◽  
LM Jackman ◽  
QN Porter ◽  
GR Underwood
Keyword(s):  
Magnetic Resonance ◽  
Long Range ◽  
Iterative Procedure ◽  
Proton Magnetic Resonance ◽  
Chemical Shifts ◽  
Coupling Constants ◽  
Methyl Derivatives ◽  
Magnetic Resonance Spectra

The proton magnetic resonance spectra of indolizine, indolizine-1,3-d2, 1- and 2-methylindolizine, 2,3-, 2,5-, 2,6-, and 2,7-dimethylindolizine and 1-, 2-, and 3-azaindolizine have been determined at 100 and/or 60 Mc/s. Unequivocal assignments have been made to all protons and the coupling constants and chemical shifts for indolizine and its aza analogues have been obtained by an iterative procedure. Long-range coupling constants involving protons separated by five and six bonds have been observed.

High-Resolutjon nuclear-magnetic-resonance spectra of hydrocarbon groupings VI. The hydrogen spectra of carbon-13 substituted ethane, ethylene and acetylene

1962 ◽  
Vol 269 (1338) ◽  
pp. 385-403 ◽  
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
High Resolution ◽  
Long Range ◽  
Experimental Results ◽  
Coupling Constants ◽  
Nuclear Magnetic Resonance Spectra ◽  
Magnetic Resonance Spectra ◽  
Nuclear Magnetic

High-resolution spectra have been obtained from the hydrogen nuclei of appropriate isotopic mixtures of ethane, ethylene and acetylene containing one or two magnetic 13 C nuclei. Analysis of these spectra has yielded the magnitudes of all but one of the possible inter - nuclear coupling constants in these molecules, including those between pairs of carbon nuclei. Where a given molecule has several coupling constants between pairs of the same type of nuclei the relative signs of these have also been determined. Discussion of the experimental results in terms of current theoretical treatments shows that in nearly all cases the contact, H 3 , term is the most important one in determining the magnitude of the coupling constants. Only in the case of the J CC and the long-range J ' CH coupling constants of acetylene does it appear to be necessary to consider appreciable contributions from other terms.

Proton magnetic resonance spectra of some β-methylstyrenes, β,β-dimethylstyrenes, and α-methylstilbenes; and a discussion of long-range shieldingand coupling effects in these and related systems

1965 ◽  
Vol 18 (11) ◽  
pp. 1759 ◽  
Author(s):  
H Rottendorf ◽  
S Sternhell ◽  
JR Wilmshurst
Keyword(s):  
Magnetic Resonance ◽  
Long Range ◽  
Proton Magnetic Resonance ◽  
Coupling Constants ◽  
Coupling Effects ◽  
Styrene Derivatives ◽  
Shielding Effects ◽  
Magnetic Resonance Spectra

The preparation of some new β,β-dimethylstyrenes and α-methylstilbenes is described and their p.m.r. spectra are reported. The long-range shielding effects in β,β-dimethylstyrenes and other styrene derivatives are discussed. The differences between the cisoid and transoid allylic coupling constants in β,β-dimethylstyrenes are much smaller than the corresponding differences in simple propenes. No appreciable (J ≥ 0.3 c/s) coupling between the non-equivalent methyl protons in β,β-dimethylstyrenes has been observed. Long-range coupling in the compounds investigated appears to be independent of ring substitution. Some general features of allylic coupling are discussed.

Long-range coupling in substituted coumarins

1968 ◽  
Vol 21 (10) ◽  
pp. 2445 ◽  
Author(s):  
MW Jarvis ◽  
AG Moritz
Keyword(s):  
Magnetic Resonance ◽  
High Resolution ◽  
Long Range ◽  
Proton Magnetic Resonance ◽  
Very High ◽  
Substituted Coumarins ◽  
Magnetic Resonance Spectra

The proton magnetic resonance spectra of some substituted coumarins and furanocoumarins have been examined under very high resolution (0.1 Hz). Trans-annular long-range spin-spin couplings across four, five, six, and seven bonds are reported.

Nuclear magnetic resonance spectra of the epihalohydrins: II. Spectral analyses and structural correlations for all the epihalohydrins

1970 ◽  
Vol 48 (7) ◽  
pp. 1046-1053 ◽  
Author(s):  
C. J. Macdonald ◽  
W. F. Reynolds
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Long Range ◽  
Propylene Oxide ◽  
Proton Magnetic Resonance ◽  
Dipole Moments ◽  
Coupling Constants ◽  
Vicinal Coupling Constants ◽  
Nuclear Magnetic Resonance Spectra ◽  
Magnetic Resonance Spectra

Complete analyses of the proton magnetic resonance spectra of propylene oxide, epifluorohydrin, epibromohydrin, and epiiodohydrin shows that in all cases the cisoid coupling constants over four bonds are negative, and the transoid coupling constants positive. Dipole moments, together with the vicinal coupling constants of the CH—CH2X moiety, are used to establish the probable conformations for all the epihalohydrins. Conformational factors appear to obscure any possible relationship between substituent electronegativity and long-range coupling constants.

The configurations and P.M.R. spectra of iodo lactones and oxymercurials derived from some 5-Norbornene-2-endo-carboxylic acids

1969 ◽  
Vol 22 (6) ◽  
pp. 1157 ◽  
Author(s):  
DN Ford ◽  
W Kitching ◽  
PR Wells
Keyword(s):  
Magnetic Resonance ◽  
Dicarboxylic Acid ◽  
Carboxylic Acids ◽  
Long Range ◽  
Proton Magnetic Resonance ◽  
General Pattern ◽  
Coupling Constants ◽  
Trans Addition ◽  
Magnetic Resonance Spectra

Iodo lactones and chloromercuri lactones derived from a number of 2- and 3-methyl-5-norbornene-2-endo-carboxylic acids have been prepared and characterized. Analyses of 60-MHz and 100-MHz proton magnetic resonance spectra have estab- lished their configurations, which conform to a general pattern of trans-addition. Criteria for stereochemical assignments in this system can be based upon identifiable vicinal, geminal, and some long-range 1H-1H and 1H-199Hg coupling constants. These criteria are used to establish that 5-norbornene-2-endo,3-endo-dicarboxylic acid and its derivatives do not follow the cis-oxymercuration route previously suggested.

Nuclear magnetic resonance studies. XVIII.The proton parameters of some bicyclo[2•2•2]octane derivatives

1969 ◽  
Vol 47 (19) ◽  
pp. 3515-3528 ◽  
Author(s):  
Gurudata Gurudata ◽  
J. B. Stothers
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
High Resolution ◽  
Long Range ◽  
Coupling Constants ◽  
Magnetic Resonance Studies ◽  
Anisotropic Effect ◽  
Shielding Effects ◽  
Nuclear Magnetic

The high resolution proton spectra of ten substituted bicyclo[2•2•2]octenes and octanes have been analyzed. The proton shieldings and coupling constants are discussed with particular emphasis on the stereochemical dependence of these parameters. Evidence bearing on the anisotropic effect of carbonyl bonds is presented to substantiate other recent findings on these shielding effects. Certain long-range couplings permit stereochemical assignments.

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