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Available through Wiley Online Library [3] (John Wiley & Sons), SpecInfo on the Internet NMR is a collection of approximately 440,000 NMR spectra (organized as 13 C, 1 H, 19 F, 31 P, and 29 Si NMR databases). The data are accessed via the Internet using a Java interface and are stored in a server developed jointly with BASF. The software ...
To be NMR-active, a nucleus must have a non-zero nuclear spin (I ≠ 0). [8] It is this non-zero spin that enables nuclei to interact with external magnetic fields and show signals in NMR. Atoms with an odd sum of protons and neutrons exhibit half-integer values for the nuclear spin quantum number (I = 1/2, 3/2, 5/2, and so on). These atoms are ...
In practice, the value of T 2 *, which is the actually observed decay time of the observed NMR signal, or free induction decay (to 1 / e of the initial amplitude immediately after the resonant RF pulse), also depends on the static magnetic field inhomogeneity, which may be quite significant. (There is also a smaller but significant ...
Data must be entered in the NMR-STAR format, conversion from other common formats can be carried out using the STARch file converter provided at the site. [13] The site also contains an NMR-STAR template generator which produces formatted tables where NMR data can be entered. [14] NMR time-domain data is uploaded separately via ftp. [15]
Experimental magnetic resonance imaging systems: NMR spectrometer at 400 MHz (9.4 T) to 500 MHz (11.7 T) 10 1 T decatesla 10 T: 100 kG: 11.7 T: 117 kG: 16 T: 160 kG: Levitate a frog by distorting its atomic orbitals [16] 23.5 T: 235 kG: 1 GHz NMR spectrometer [17] 32 T: 235 kG: Strongest continuous magnet field produced by all-superconducting ...
19 F NMR chemical shifts in the literature vary strongly, commonly by over 1 ppm, even within the same solvent. [5] Although the reference compound for 19 F NMR spectroscopy, neat CFCl 3 (0 ppm), [6] has been used since the 1950s, [7] clear instructions on how to measure and deploy it in routine measurements were not present until recently. [5]
Nucleic acid NMR is the use of nuclear magnetic resonance spectroscopy to obtain information about the structure and dynamics of nucleic acid molecules, such as DNA or RNA. It is useful for molecules of up to 100 nucleotides, and as of 2003, nearly half of all known RNA structures had been determined by NMR spectroscopy.
Nitrogen-15 is frequently used in nuclear magnetic resonance spectroscopy (NMR), because unlike the more abundant nitrogen-14, that has an integer nuclear spin and thus a quadrupole moment, 15 N has a fractional nuclear spin of one-half, which offers advantages for NMR like narrower line width.