scholarly journals Complete Analysis of the 100 MHz 1H NMR Spectrum of Triphenylphosphine.

1974 ◽  
Vol 28a ◽  
pp. 249-250 ◽  
Author(s):  
S. Sørensen ◽  
H. J. Jakobsen ◽  
F. Lindeløv ◽  
Terje Østvold ◽  
Alf Bjørseth ◽  
...  
Keyword(s):  
1H Nmr ◽  
Complete Analysis ◽  
Nmr Spectrum

Complete analysis of the 1H nmr spectrum of tetrahydrothiophene

1980 ◽  
Vol 58 (22) ◽  
pp. 2340-2348 ◽  
Author(s):  
Angel Luis Esteban ◽  
Ernesto Díez
Keyword(s):  
Potential Energy ◽  
1H Nmr ◽  
Time Scale ◽  
Complete Analysis ◽  
Nmr Spectrum ◽  
H Nmr ◽  
Karplus Relationship ◽  
The One

The 1H nmr spectrum of tetrahydrothiophene has been analyzed. The best set of coupling values (Hz) is: [Formula: see text], [Formula: see text], [Formula: see text], [Formula: see text], [Formula: see text], [Formula: see text], [Formula: see text], [Formula: see text], [Formula: see text] (A and B refer to α-and β-protons and c and t denote respectively the same and opposite sides of the ring). The variances observed between the values of this set and those reported by Lozach etal., particularly the interchange of the [Formula: see text] and [Formula: see text] couplings, are discussed and it is concluded that our set is the one that reproduces the most fine details of the spectrum profile. The proposed set has been selected as being the most physically meaningful, from amongst 24 equally valid sets of couplings, on the basis of a better agreement with the [Formula: see text] and [Formula: see text] values calculated from a Karplus relationship and from the INDO-FPT method respectively. In these calculations it was assumed that the molecule was interconverting rapidly (on the nmr time scale) between two puckered conformations with C2 symmetry. A detailed discussion of the dependence of the couplings on the height of the pseudorotational barrier and on the temperature indicate that the minimum values of the potential energy correspond to these conformations.

THE STEREOCHEMISTRY OF 2-t-BUTYL-2-CYANO-3-PHENYLCYCLOBUTANONE BY COMPLETE ANALYSIS OF ITS 1H NMR SPECTRUM

1982 ◽  
pp. 143-147
Author(s):  
MIRCEA D. GHEORGHIU ◽  
LUMINITA PÂRVULESCU ◽  
CONSTANTIN DRÂGHICI ◽  
MIHAI ELIAN
Keyword(s):  
1H Nmr ◽  
Complete Analysis ◽  
Nmr Spectrum

21,22-Disubstituted 18α,19βH-Ursane Derivatives with Oxabicyclooctane System in Ring E

1993 ◽  
Vol 58 (1) ◽  
pp. 173-190 ◽  
Author(s):  
Eva Klinotová ◽  
Jiří Klinot ◽  
Václav Křeček ◽  
Miloš Buděšínský ◽  
Bohumil Máca
Keyword(s):  
Spectral Data ◽  
Spin Systems ◽  
Coupling Constants ◽  
Complete Analysis ◽  
Nmr Spectrum ◽  
Proton Proton ◽  
H Nmr ◽  
Proton Coupling ◽  
C Nmr

Reaction of 3β-acetoxy-21,22-dioxo-18α,19βH-ursan-28,20β-olide (IIIa) and 20β,28-epoxy-21,22-dioxo-19α,19βH-ursan-3β-yl acetate (IIIb) with diazomethane afforded derivatives XII-XIV with spiroepoxide group in position 21 or 22, which were further converted into hydroxy derivatives XV and XVII. Ethylene ketals VIII-X were also prepared. In connection with the determination of position and configuration of the functional groups at C(21) and C(22), the 1H and 13C NMR spectral data of the prepared compounds are discussed. Complete analysis of two four-spin systems in the 1H NMR spectrum of bisethylenedioxy derivative Xb led to the proton-proton coupling constants from which the structure with two 1,4-dioxane rings condensed with ring E, and their conformation, was derived.

Study on the Inclusion Behavior of Cucurbit [n] uril with Phenylalanine

2011 ◽  
Vol 197-198 ◽  
pp. 1153-1156
Author(s):  
Ning Chen ◽  
Ya Bin Li
Keyword(s):  
1H Nmr ◽  
Interaction Mechanism ◽  
Acetate Buffer Solution ◽  
Molar Ratio ◽  
High Concentration ◽  
Buffer Solution ◽  
Visible Absorption ◽  
Nmr Spectrum ◽  
Application Range ◽  
Uv Visible

The characteristics of host-guest complexes between cucurbit[n]uril (CB [n]) and phenylalanine were investigated by UV-visible absorption spectroscopy in acetate buffer solution at room temperature. It was found that the UV-visible absorption increased steadily with constantly dropping the high concentration of cucurbit[6]uril (CB [6]) and cucurbit[8]uril (CB [8]) in the phenylalanine solution which indicates that there are some interaction betweenCB [n] and phenylalanine.Then CB [6] and phenylalanine at molar ratio of 1:1 to weigh while CB [8] and phenylalanine at molar ratio of 1:2, respectively, are both demonstrated by 1H NMR spectra. 1H NMR spectrum of complexes was obtained, indicating an enthalpic driving force for host-guest complexes. The possible interaction mechanism and inclusion mode were also discussed. This work may extend the application range of CB [n] in supramolecular and pharmaceutical analysis.

scholarly journals Identification of Methyl Resonances in the 1H NMR Spectrum of Incubated Blood Cell Lysates

1989 ◽  
Vol 264 (4) ◽  
pp. 2100-2107 ◽  
Author(s):  
G L Mendz ◽  
M N McCall ◽  
P W Kuchel
Keyword(s):  
Blood Cell ◽  
1H Nmr ◽  
Nmr Spectrum ◽  
Cell Lysates

Solving the 31P{1H} NMR spectrum of (Me3Si)3P7 as B[AC]3 case

2017 ◽  
Vol 192 (6) ◽  
pp. 727-731
Author(s):  
Eberhard Matern ◽  
Michael Engelhardt ◽  
Gerhard Hägele
Keyword(s):  
1H Nmr ◽  
Nmr Spectrum

scholarly journals One-Dimensional 13C NMR Is a Simple and Highly Quantitative Method for Enantiodiscrimination

Molecules ◽  
2018 ◽  
Vol 23 (7) ◽  
pp. 1785 ◽  
Author(s):  
Peter Lankhorst ◽  
Jozef van Rijn ◽  
Alexander Duchateau
Keyword(s):  
1H Nmr ◽  
13C Nmr ◽  
Quantitative Method ◽  
Enantiomeric Excess ◽  
Nmr Spectrum ◽  
One Dimensional ◽  
Nmr Method ◽  
Relative Standard ◽  
Excess Value ◽  
Chiral Solvating Agent

The discrimination of enantiomers of mandelonitrile by means of 1D 13C NMR and with the aid of the chiral solvating agent (S)-(+)-1-(9-anthryl)-2,2,2-trifluoroethanol (TFAE) is presented. 1H NMR fails for this specific compound because proton signals either overlap with the signals of the chiral solvating agent or do not show separation between the (S)-enantiomer and the (R)-enantiomer. The 13C NMR method is validated by preparing artificial mixtures of the (R)-enantiomer and the racemate, and it is shown that with only 4 mg of mandelonitrile a detection limit of the minor enantiomer of 0.5% is obtained, corresponding to an enantiomeric excess value of 99%. Furthermore, the method shows high linearity, and has a small relative standard deviation of only 0.3% for the minor enantiomer when the relative abundance of this enantiomer is 20%. Therefore, the 13C NMR method is highly suitable for quantitative enantiodiscrimination. It is discussed that 13C NMR is preferred over 1H NMR in many situations, not only in molecules with more than one chiral center, resulting in complex mixtures of many stereoisomers, but also in the case of molecules with overlapping multiplets in the 1H NMR spectrum, and in the case of molecules with many quaternary carbon atoms, and therefore less abundant protons.

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