Carbon-13-carbon-13 coupling constants. VI. Homonuclear double resonance experiments for carbon-13 nuclear magnetic resonance assignments

1972 ◽  
Vol 76 (21) ◽  
pp. 2972-2974 ◽  
Author(s):  
Harry C. Dorn ◽  
Gary E. Maciel
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Double Resonance ◽  
Resonance Assignments ◽  
Coupling Constants ◽  
Nuclear Magnetic

The nuclear magnetic resonance spectra and stereochemistry of 4-Benzoyloxy-1-thiaflavans

1967 ◽  
Vol 20 (10) ◽  
pp. 2235 ◽  
Author(s):  
GF Katekar ◽  
AG Moritz
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Double Resonance ◽  
Heterocyclic Ring ◽  
Coupling Constants ◽  
Spectral Parameters ◽  
Nuclear Magnetic Resonance Spectra ◽  
Cis And Trans ◽  
Magnetic Resonance Spectra ◽  
Nuclear Magnetic

The nuclear magnetic resonance spectra of cis- and trans-4-benzoyloxy- 1-thiaflavan in deuterochloroform have been investigated at 60 Mc/s. The spectral parameters for the heterocyclic ring protons have been obtained by analysis of the frequency-sweep double-resonance spectra and verified by an iterative technique using a digital computer. Long- range coupling constants were observed between the protons at C 4 and C 5 (J 0.8 c/s) and between the protons at C 2 and C 4 (J 0.2 c/s) for the cis isomer.

Conformational dynamics detected by nuclear magnetic resonance NOE values and J coupling constants

1988 ◽  
Vol 110 (11) ◽  
pp. 3393-3396 ◽  
Author(s):  
Horst. Kessler ◽  
Christian. Griesinger ◽  
Joerg. Lautz ◽  
Arndt. Mueller ◽  
Wilfred F. Van Gunsteren ◽  
...  
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Conformational Dynamics ◽  
Coupling Constants ◽  
J Coupling ◽  
J Coupling Constants ◽  
Nuclear Magnetic

Studies of specifically fluorinated carbohydrates. Part I. Nuclear magnetic resonance studies of hexopyranosyl fluoride derivatives

1969 ◽  
Vol 47 (1) ◽  
pp. 1-17 ◽  
Author(s):  
L. D. Hall ◽  
J. F. Manville ◽  
N. S. Bhacca
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Angular Dependence ◽  
Chemical Shifts ◽  
Relative Orientation ◽  
Coupling Constants ◽  
Pyranose Ring ◽  
Spectral Parameters ◽  
Magnetic Resonance Studies ◽  
Nuclear Magnetic

A detailed study has been made of both the 1H and 19F nuclear magnetic resonance (n.m.r.) spectra of a series of hexopyranosyl fluoride derivatives. Some of the 1H spectra were measured at 220 MHz. The 1H spectral parameters define both the configuration and the conformation of each of these derivatives. Study of the 19F n.m.r. parameters revealed several stereospecific dependencies. The 19F chemical shifts depend upon, (a) the orientation of the fluorine substituent with respect to the pyranose ring and, (b) the relative orientation of other substituents attached to the ring; for acetoxy substituents, these configurational dependencies appear to be additive. The vicinal19F–1H coupling constants exhibit a marked angular dependence for which Jtrans = ca. 24 Hz whilst Jgauche = 1.0 to 1.5 Hz for [Formula: see text] and 7.5 to 12.6 Hz for [Formula: see text] The geminal19F–1H couplings depend on the orientation of the substituent at C-2; when this substituent is equatorial JF,H is ca. 53.5 Hz and when it is axial the value is ca. 49 Hz.

Studies of specifically fluorinated carbohydrates. Part II. Nuclear magnetic resonance studies of pentopyranosyl fluoride derivatives

1969 ◽  
Vol 47 (1) ◽  
pp. 19-30 ◽  
Author(s):  
L. D. Hall ◽  
J. F. Manville
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Magnetic Resonance Spectroscopy ◽  
Nuclear Magnetic Resonance Spectroscopy ◽  
Chemical Shifts ◽  
Coupling Constants ◽  
Resonance Spectroscopy ◽  
Magnetic Resonance Studies ◽  
Conformational Model ◽  
Nuclear Magnetic

Detailed studies, by 1H and 19F nuclear magnetic resonance spectroscopy, of a series of fully esterified pentopyranosyl fluorides, show that all such derivatives favor that conformer in which the fluorine substituent is axially oriented. This conclusion is supported by separate considerations of the vicinal and geminal19F–1H and 1H–1H coupling constants, of the long-range (4J) 1H–1H and 19F–1H coupling constants and of the 19F chemical shifts. The limitations of the above conformational model are discussed.

The influence of charge on nuclear magnetic resonance isotope effects

1987 ◽  
Vol 65 (12) ◽  
pp. 2707-2712 ◽  
Author(s):  
Roderick E. Wasylishen ◽  
Neil Burford
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Isotope Effects ◽  
Heavy Atom ◽  
Coupling Constants ◽  
Molecular Orbital Calculations ◽  
Isoelectronic Series ◽  
Deuterium Isotope Effects ◽  
Charged Ions ◽  
Nuclear Magnetic

Deuterium isotope effects on the 31P shielding constants and spin–spin coupling constants in the isoelectronic series, PH2−, PH3, PH4+, are examined. Also, deuterium isotope effects on the nuclear magnetic resonance parameters of SnH3− are examined and compared with our earlier results on SnH4 and SnH3+. The experimental results are analyzed using the models of Jameson and Osten. In each isoelectronic series it is found that the isotope effects on the heavy atom chemical shifts are largest for the negatively charged ions and essentially zero for the positively charged ions, as predicted by recent molecular orbital calculations. The primary isotope effects on J(A,H) are positive for all species containing lone-pair electrons, otherwise Δp1J(A,H) is negative. The primary and secondary isotope effects on J(Sn,H) in the SnH3− ion are the largest reported to date.

High-resolution nuclear-magnetic-resonance spectra of hydrocarbon groupings - V. ABCX spectra of vinyl fluoride and 3-methylbut-l-ene

1961 ◽  
Vol 263 (1312) ◽  
pp. 136-148 ◽  
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
High Resolution ◽  
Coupling Constants ◽  
Vinyl Fluoride ◽  
General Properties ◽  
Nuclear Magnetic Resonance Spectra ◽  
Magnetic Resonance Spectra ◽  
Nuclear Magnetic

Some general properties of ABCX -type spectra are discussed. It is shown that it is possible to deduce from such spectra the relative signs of all inter-nuclear coupling constants. Analyses are presented of the hydrogen (proton) spectra from the vinyl groups of vinyl fluoride and 3-methylbut-l-ene, and of the fluorine spectrum of the former molecule. It is shown that all HF coupling constants in vinyl fluoride are of the same sign as the cis and trans HH coupling constants.

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