Results 241 to 250 of about 581,535 (297)

Accurate determinations of one-bond 13C–13C couplings in 13C-labeled carbohydrates

Journal of Magnetic Resonance, 2013
Carbon plays a central role in the molecular architecture of carbohydrates, yet the availability of accurate methods for (1)D(CC) determination has not been sufficiently explored, despite the importance that such data could play in structural studies of oligo- and polysaccharides.
Hugo F, Azurmendi, Darón I, Freedberg
openaire   +2 more sources

13C-13C Coupling in [1.1.1]Propellane

Tetrahedron Letters, 1990
Abstract The C1–C2 coupling constant in [1.1.1]propellane is measured to be 9.9 ± .1 Hz. The CH bond is sp 2.1 and the CCH 2 bond is estimated to be sp 8.6 -sp 4.8 . The remaining orbital at each bridgehead carbon is sp 0.5 .
Ronald M. Jarret, Leonarda Cusumano
openaire   +1 more source

Editing of 13C13C satellite spectra

Journal of Magnetic Resonance (1969), 1988
Abstract The SEMUT and DEPT spectral editing techniques are combined with the techniques INADEQUATE and SLAP for observation of 13C13C satellites in natural abundance samples. The theory is documented by experimental edited spectra, in some cases exhibiting dramatic simplification compared to the normal spectra.
Niels Chr Nielsen, Henrik Bildsøe, Hans J jakobsen, Ole W S/orensen   +3 more
openaire   +1 more source

13C–13C dipolar spectra in solids

The Journal of Chemical Physics, 1977
A single crystal NMR study has been made of the 13C–13C dipolar interaction in oxalic acid dihydrate (HOX) and diammonium oxalate monohydrate (DAOX). The results show that indirect contributions to the interaction are negligibly small so that the dipolar tensor provides information on the C–C bond length and orientation in the crystal lattice.
H. van Willigen, R. G. Griffin, R. A. Haberkorn   +2 more
openaire   +1 more source

Elastic scattering of 13C from 13C

Nuclear Physics A, 1973
Abstract Angular distributions and excitation functions for 13 C+ 13 C elastic scattering have been measured in the energy range E (lab) = 14.0–27.5 MeV. The angular distributions at E (lab) = 15, 16, 18 and 20 MeV can be described fairly well with the method of molecular wave functions.
H.-D. Helb, P. Dück, G. Hartmann, G. Ischenko, F. Siller, H. Voit   +5 more
openaire   +1 more source

J(13C13C) in allylmetal complexes

Journal of Organometallic Chemistry, 1982
Abstract The J(13C13C) coupling constants of simple allyl compounds of nickel, chromium, magnesium and lithium have been determined on natural abundance samples. In transition metal complexes 1J(13C13C) is reduced to 41 Hz (Ni) whilst in allyllithium it is 58.7 Hz.
Reinhard Benn, Anna Rufińska
openaire   +1 more source

The influence of electronegative substituents on coupling constants 1J(13C13C), 1J(13C77Se), 1J(13C125Te), and 1J(13C113Cd)

Journal of Fluorine Chemistry, 1991
Abstract A study of NMR coupling constants, 1J(13C13C), of compounds containing a CF3 group has revealed that the values for the coupling of the CF3 carbon with the neighbouring carbon are exceptionally large [1]. In a series of compounds in which the CF3 group is bonded to a spa3, sp2, and sp-carbon the 1J(CC) values show a very good linear ...
W. Gombler, F. Behle, G. Bollmann
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Biosynthese de la botryodiplodine, mycotoxine de penicillium roqueforti: Incorporations d'acetate[1-13C], [2-13C], [1-2 13C]et d'acide orsellinique 2-13C-carboxyle 13C], [3-4 13C]

Tetrahedron, 1984
Resume Les incorporations d'acetate [1- 13 C], [2- 13 C], [1-2 13 C]et d'acide orsellinique [2- 13 C, carboxyle- 13 C], [3-4 13 C] dans la botryodiplodine montrent que cette mycotoxine est biosynthetisee par la voie des polycetoacides. L'acide orsellinique est un precurseur de la botryodiplodine.
F. Renauld, S. Moreau, A. Lablache-Combier   +2 more
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1J(13C, 13C) in (η4-butadien)übergangsmetallkomplexen

Journal of Organometallic Chemistry, 1987
The indirect scalar spin-spin coupling constant 1J(13C, 13C) has been determined in dissolved (η4-diene)transition metal complexes using natural-abundance samples of complexes of Zr, Hf, Th, Mo, W, Fe, and Co. 1J(13C, 13C) is a sensitive probe for metal-diene bonding in such complexes: In planar η4-s-cis-diene compounds with similar carbon bond lengths,
Reinhard Benn, Anna Rufińska
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13C-13C Coupling-Constants in Carboxylate Esters

Microchemical Journal, 1993
Abstract Isotopic enrichment or a multipulse NMR experiment (INADEQUATE) was utilized to measure the 13 C- 13 C coupling constants for a collection of carboxylate esters. Significantly different values were measured for the C 2 C 3 bond of endo - and exo -2-norbornyl acetates. The 13 C- 13 C coupling constants for the CαCO bond of substituted
R.M. Jarret, L. Cusumano, M. Dinztner, M. Fortin, K. Pothier, J. Connolly, M. Biondi, T. Morrison   +7 more
openaire   +1 more source