Results 251 to 260 of about 494,170 (294)
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Bulletin of the Academy of Sciences of the USSR Division of Chemical Science, 1979
1. An assignment was made of the lines in the13C and1H NMR spectra of the diterpene alcohol lagochilin. 2. The spectral parameters were compared with the characteristic structural traits of lagochilin, which can be used to establish the structure, configuration, and conformation of diterpenes of the labdane series.
O. S. Chizhov +2 more
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1. An assignment was made of the lines in the13C and1H NMR spectra of the diterpene alcohol lagochilin. 2. The spectral parameters were compared with the characteristic structural traits of lagochilin, which can be used to establish the structure, configuration, and conformation of diterpenes of the labdane series.
O. S. Chizhov +2 more
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Chemistry of Natural Compounds, 1972
The NMR spectra of 12 coumestans in trifluoroacetic acid have been studied. The same features of the chemical shifts of the ring protons are found in the spectra of the coumestans as in the spectra of the coumarins.
L. L. Simonova +3 more
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The NMR spectra of 12 coumestans in trifluoroacetic acid have been studied. The same features of the chemical shifts of the ring protons are found in the spectra of the coumestans as in the spectra of the coumarins.
L. L. Simonova +3 more
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Chemistry of Heterocyclic Compounds, 1978
The 13C and 1H NMR spectra of 1-arylaziridines, 2-phenyl-1-arylaziridines, and 2-aryl-1-phenylaziridines were studied. The additive contributions of aziridinyl, 1-phenyl-2-aziridinyl, and 2-phenyl-1-aziridinyl substituents to the shielding of the aromatic protons were calculated.
�. �. Liepin'sh +3 more
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The 13C and 1H NMR spectra of 1-arylaziridines, 2-phenyl-1-arylaziridines, and 2-aryl-1-phenylaziridines were studied. The additive contributions of aziridinyl, 1-phenyl-2-aziridinyl, and 2-phenyl-1-aziridinyl substituents to the shielding of the aromatic protons were calculated.
�. �. Liepin'sh +3 more
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2010
NMR spectra of many systems governed by axially symmetric second rank tensor interactions exhibit P2(cos θ) dependence on the angle 9 between the symmetry axis and the externally applied magnetic field. For the so-called "powder samples" consisting of many randomly oriented domains the resulting spectrum is the superposition of contributions from each ...
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NMR spectra of many systems governed by axially symmetric second rank tensor interactions exhibit P2(cos θ) dependence on the angle 9 between the symmetry axis and the externally applied magnetic field. For the so-called "powder samples" consisting of many randomly oriented domains the resulting spectrum is the superposition of contributions from each ...
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ChemInform, 2005
AbstractFor Abstract see ChemInform Abstract in Full Text.
Ludger Ernst, Kerstin Ibrom
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AbstractFor Abstract see ChemInform Abstract in Full Text.
Ludger Ernst, Kerstin Ibrom
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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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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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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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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
openaire +1 more source