Phosphoric amides. Bridge effect in geminal coupling constants between31P and13C nuclei

1998 ◽  
Vol 36 (S1) ◽  
pp. S212-S214 ◽  
Author(s):  
T. A. Modro ◽  
A. M. Modro ◽  
P. Bernatowicz ◽  
W. Schilf ◽  
L. Stefaniak
Keyword(s):  
Coupling Constants ◽  
Geminal Coupling

Conformational Studies on 1,3-Dioxepanes. Part IV. Applications of Geminal Coupling Constants to Conformational Analysis of 1,3-Dioxepanes

1974 ◽  
Vol 52 (24) ◽  
pp. 4062-4071 ◽  
Author(s):  
T. Bruce Grindley ◽  
Walter A. Szarek
Keyword(s):  
Conformational Analysis ◽  
Coupling Constants ◽  
Conformational Studies ◽  
Vicinal Coupling Constants ◽  
Geminal Coupling ◽  
Derivatives Of ◽  
Acetal Carbon

The magnitude of —OCH2O— group geminal H,H coupling contants, the size of the vicinal coupling constants, and the tenets of conformational analysis were used to establish that in solution the conformation of the 1,3-dioxepane rings in derivatives of 1,3:2,5-di-O-methylenemannitol and 2,5-O-methylenemannitol is predominantly the twist-chair in which the C2 axis passes through the acetal carbon.

Nitrogen-15 coupling constants: Geminal coupling,2J(15NH), incis- andtrans-aldonitrones and vicinal coupling,3J(15NH), incis-andtrans-ketimines, oxaziridines and nitrones

1980 ◽  
Vol 14 (6) ◽  
pp. 528-533 ◽  
Author(s):  
Derek R. Boyd ◽  
Michael E. Stubbs ◽  
N. J. Thompson ◽  
Herman J. C. Yeh ◽  
Donald M. Jerina ◽  
...  
Keyword(s):  
Coupling Constants ◽  
Geminal Coupling

Eine 15N-NMR-untersuchung einiger trimethylstannylhydrazine / A15N-NMR study of some trimethylstannylhydrazines

1989 ◽  
Vol 44 (6) ◽  
pp. 653-658 ◽  
Author(s):  
Bernd Wrackmeyer ◽  
Theo Gasparis-Ebeling ◽  
Heinrich Nöth
Keyword(s):  
Nmr Spectroscopy ◽  
Lone Electron Pair ◽  
Electron Pair ◽  
Relative Magnitude ◽  
Coupling Constants ◽  
15N Nmr ◽  
Nmr Study ◽  
Geminal Coupling ◽  
In Cis ◽  
First Time

The trimethylstannylhydrazines (Me3Sn)2N-NMe2 (1), Me3Sn(Me)N-N(Me)SnMe3 (2), (Me3Sn)2N-N(Me)SnMe3 (3), and (M e3Sn)2N-N(Ph)SnMe3 (4) have been studied by δ15N NMR at natural abundance. A correlation between δ15N of hydrazines and δI5N of corresponding am ines (replacement of one N-atom by the CH-unit) is proposed in order to estimate δI5N values and to support the non-trivial assignment of 15N resonances of hydrazines. Geminal coupling constants 2J(119SnN 15N) have been observed for the first time. Their relative magnitude is related to the probability of the N-Sn bond being in cis-position with respect to the orientation of the lone electron pair at the 15N nucleus in the 119Sn-N-15N fragment. Treatment of 4 with phenylacetylene causes non-selective cleavage of the Sn-N bonds, leading to the trim ethylstannylhydrazines 5 and 6 which have been characterized by 119Sn and 15N NMR spectroscopy in solution

SOLVENT EFFECTS AS AN AID IN THE ANALYSIS OF THE PROTON MAGNETIC RESONANCE SPECTRUM OF VINYL BROMIDE

1960 ◽  
Vol 38 (11) ◽  
pp. 2066-2073 ◽  
Author(s):  
T. Schaefer ◽  
W. G. Schneider
Keyword(s):  
Chemical Shift ◽  
Solvent Effects ◽  
Resonance Spectrum ◽  
Proton Magnetic Resonance Spectrum ◽  
Coupling Constants ◽  
Vinyl Bromide ◽  
Proton Coupling ◽  
Geminal Proton ◽  
Geminal Coupling ◽  
Cis And Trans

By making use of specific solvent effects it has been possible to vary the relative chemical shift between the geminal protons of vinyl bromide from about +10 cycles/sec to −4 cycles/sec (at 60 Mc/sec) and to study the resultant changes in the proton resonance spectrum in the limiting region of zero chemical shift. Of particular interest is the growth and displacement of the combination lines, which appear in the resonance signals of the proton bonded to the same carbon atom as the bromine. From the variation of the six possible lines in this region it was confirmed that the cis and trans proton coupling constants must have the same sign. The intensity distribution of the lines in the geminal proton region require the geminal coupling constant to be of opposite sign to the other two.

Interproton allylic spin-spin coupling involving exocyclic groups

1972 ◽  
Vol 25 (8) ◽  
pp. 1669 ◽  
Author(s):  
GP Newsoroff ◽  
S Sternhell
Keyword(s):  
Coupling Constants ◽  
Spin Coupling ◽  
Dihedral Angles ◽  
Ring Size ◽  
Methylene Groups ◽  
Exocyclic Methylene ◽  
Geminal Coupling ◽  
The Absolute ◽  
Absolute Magnitudes ◽  
Spin Spin Coupling

N.m.r. parameters for 55 compounds incorporating exocyclic groups were obtained. In unstrained structures the relative (as well as the absolute) magnitudes of transoid and cisoid allylic coupling constants depend on the magnitudes of the dihedral angles but additional effects were also identified. The magnitudes of geminal coupling constants between the protons of exocyclic methylene groups and of homoallylic coupling constants involving exocyclic ethylidene and isopropylidene groups vary systematically with ring size.

The influence of an adjacent sulphur atom on geminal coupling constants in methylene groups

Tetrahedron ◽  
1968 ◽  
Vol 24 (4) ◽  
pp. 1989-1995 ◽  
Author(s):  
Y. Allingham ◽  
R.C. Cookson ◽  
T.A. Crabb
Keyword(s):  
Coupling Constants ◽  
Sulphur Atom ◽  
Methylene Groups ◽  
Geminal Coupling
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