Results 221 to 230 of about 223,391 (261)
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1970
NMR spectra are presented in order of increasing oxidation and substitution of the flavonoid nucleus for flavones, flavonols, isoflavones, dihydroflavonols, flavanones, chalcones and aurones.
Tom J. Mabry +2 more
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NMR spectra are presented in order of increasing oxidation and substitution of the flavonoid nucleus for flavones, flavonols, isoflavones, dihydroflavonols, flavanones, chalcones and aurones.
Tom J. Mabry +2 more
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The information in NMR spectra
2016This chapter analyzes the energy of a magnetic nucleus that depends on its electronic environment and the presence of magnetic nuclei in its vicinity. It covers concepts that lead to an understanding of how molecular structure affects the appearance of nuclear magnetic resonance (NMR) spectra.
Peter Atkins +2 more
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Homogeneous NMR Spectra in Inhomogeneous Fields
Science, 1996Researchers interested in high-resolution nuclear magnetic resonance (NMR) spectroscopy have long sought higher magnetic fields to enhance resolution and simplify spectra. Magnets with substantially larger fields than those available in the best commercial spectrometers are available, but the inhomogeneity is unacceptable for high ...
S, Vathyam, S, Lee, W S, Warren
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Quantitative analysis of NMR spectra with chemometrics
Journal of Magnetic Resonance, 2008The number of applications of chemometrics to series of NMR spectra is rapidly increasing due to an emerging interest for quantitative NMR spectroscopy e.g. in the pharmaceutical and food industries. This paper gives an analysis of advantages and limitations of applying the two most common chemometric procedures, Principal Component Analysis (PCA) and ...
Winning, Hanne +3 more
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Effect of Solvents on NMR Spectra of Penicillins
Journal of Pharmaceutical Sciences, 1974High-resolution NMR spectra of penicillin G and ampicillin in deuterium oxide, water, deuterated dimethyl sulfokide, and deuterated dimethyl sulfoxide-deuterium oxide were examined. The α-amino group of ampicillin could not be observed in these solvents but was observed using the pivaloyl derivative of ampicillin in deuterochloroform.
J M, Padfield, I W, Kellaway
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2013
Contents The chemical shift 464 Brief illustration 48.1: The δ scale 465 Example 48.1: Interpreting the NMR spectrum of ethanol 465 The origin of shielding constants 466 The local ...
Peter Atkins +2 more
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Contents The chemical shift 464 Brief illustration 48.1: The δ scale 465 Example 48.1: Interpreting the NMR spectrum of ethanol 465 The origin of shielding constants 466 The local ...
Peter Atkins +2 more
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1974
The definition and uses of band width and band shape were introduced in Chapter 1, Section IIE, and were illustrated briefly. However, full use of these two characteristics requires a much more extensive acquaintance with actual spectra. It is necessary to have a mental picture of the appearance of the various kinds of multiplets under different ratios
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The definition and uses of band width and band shape were introduced in Chapter 1, Section IIE, and were illustrated briefly. However, full use of these two characteristics requires a much more extensive acquaintance with actual spectra. It is necessary to have a mental picture of the appearance of the various kinds of multiplets under different ratios
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1986
The theory of chemical shifts in proton NMR can be rationalised comprehensively, and correlation data are available in tabular form to aid spectral interpretation.
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The theory of chemical shifts in proton NMR can be rationalised comprehensively, and correlation data are available in tabular form to aid spectral interpretation.
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Mass Spectra and NMR Spectra of Gangliosides Containing Fucose
1980Two gangliosides containing fucose, prepared from minipig posterior root ganglion, were analyzed as methylated, methylated-reduced and methylated-reduced-trimethylsilylated derivatives by mass spectrometry and NMR spectroscopy and shown to have the following structures:Fuc alpha 1 leads to Hex beta 1 leads to 3HexNac (comes from NeuAc) beta 1 leads to ...
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