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13 C NMR spectroscopy is much less sensitive (ca. by 4 orders of magnitude) to carbon than 1 H NMR spectroscopy is to hydrogen, because of the lower abundance (1.1%) of 13 C compared to 1 H (>99%), and because of a lower(0.702 vs. 2.8) nuclear magnetic moment.
Carbon satellites in physics and spectroscopy, are small peaks that can be seen shouldering the main peaks in the nuclear magnetic resonance (NMR) spectrum.These peaks can occur in the NMR spectrum of any NMR active atom (e.g. 19 F or 31 P NMR) where those atoms adjoin a carbon atom (and where the spectrum is not 13 C-decoupled, which is usually the case).
NMR-active nuclei, particularly those with a spin quantum number of 1/2, are of great significance in NMR spectroscopy. Examples include 1 H, 13 C, 15 N, and 31 P. [10] Some atoms with very high spin (as 9/2 for 99 Tc atom) are also extensively studied with NMR spectroscopy. [11]
is an example of a nuclide that produces no NMR signal, whereas 13 C, 31 P, 35 Cl and 37 Cl are nuclides that do exhibit NMR spectra. The last two nuclei have spin S > 1 / 2 and are therefore quadrupolar nuclei. Electron spin resonance (ESR) is a related technique in which transitions between electronic rather than nuclear spin levels ...
Bulk carbon-13 for commercial use, e.g. in chemical synthesis, is enriched from its natural 1% abundance. Although carbon-13 can be separated from the major carbon-12 isotope via techniques such as thermal diffusion, chemical exchange, gas diffusion, and laser and cryogenic distillation, currently only cryogenic distillation of methane (boiling point −161.5°C) or carbon monoxide (b.p. − ...
Examples of such NMR active nuclei are the isotopes carbon-13 and hydrogen-1 (which in NMR is conventionally known as proton NMR). The resonant frequency of each isotope is directly proportional to the strength of the applied magnetic field, and the magnetogyric or gyromagnetic ratio of that isotope.
For non-protonated carbon atoms the NOE enhancement is small while for carbons that relax by relaxation mechanisms by other than dipole-dipole interactions the NOE enhancement can be significantly reduced. This is one motivation for using deuteriated solvents (e.g. CDCl 3) in 13 C NMR. Since deuterium relaxes by the quadrupolar mechanism, there ...
In HOESY, much like NOESY is used for the cross relaxation between nuclear spins. However, HOESY can offer information about other NMR active nuclei in a spatially relevant manner. Examples include any nuclei X{Y} or X→Y such as 1 H→ 13 C, 19 F→ 13 C, 31 P→ 13 C, or 77 Se→ 13 C.