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SDBS includes 14700 1 H NMR spectra and 13000 13 C NMR spectra as well as FT-IR, Raman, ESR, and MS data. The data are stored and displayed as an image of the processed data. Annotation is achieved by a list of the chemical shifts correlated to letters which are also used to label a molecular line drawing.
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]
This occurs most frequently in compounds that contain phosphorus or fluorine, as they are both spin-1/2 nuclei of 100% abundance. For example, the 1H signals for the protons in fluoromethane are split into a doublet by the fluorine atom; conversely, the fluorine-19 NMR spectrum of this compound shows a quartet due to being split by the three ...
Solid-state 900 MHz (21.1 T [1]) NMR spectrometer at the Canadian National Ultrahigh-field NMR Facility for Solids. Solid-state nuclear magnetic resonance (ssNMR) is a spectroscopy technique used to characterize atomic-level structure and dynamics in solid materials. ssNMR spectra are broader due to nuclear spin interactions which can be categorized as dipolar coupling, chemical shielding ...
Paramagnetism diminishes the resolution of an NMR spectrum to the extent that coupling is rarely resolved. Nonetheless spectra of paramagnetic compounds provide insight into the bonding and structure of the sample. For example, the broadening of signals is compensated in part by the wide chemical shift range (often 200 ppm in 1 H NMR).
If a spectrum of an unknown chemical compound is available, a reverse search can be carried out by entering the values of the chemical shift, frequency or mass of the peaks in the NMR, FT-IR or EI-MS spectrum respectively. This type of search affords all the chemical compounds in the database that have the entered spectral characteristics. [6]
Phosphorus is commonly found in organic compounds and coordination complexes (as phosphines), making it useful to measure 31 - NMR spectra routinely. Solution 31 P-NMR is one of the more routine NMR techniques because 31 P has an isotopic abundance of 100% and a relatively high gyromagnetic ratio. The 31 P nucleus also has a spin of 1 / 2 ...
NMR spectroscopy is nucleus specific. Thus, it can distinguish between hydrogen and deuterium. The amide protons in the protein exchange readily with the solvent, and, if the solvent contains a different isotope, typically deuterium, the reaction can be monitored by NMR spectroscopy. How rapidly a given amide exchanges reflects its solvent ...