High Resolution for Chemical Shifts and Scalar Coupling Constants: The 2D Real-Time J-Upscaled PSYCHE-DIAG

ChemPhysChem ◽  
2018 ◽  
Vol 19 (22) ◽  
pp. 3166-3170 ◽  
Author(s):  
Sebastian Tassoti ◽  
Predrag Novak ◽  
Craig P. Butts ◽  
Klaus Zangger
Keyword(s):  
High Resolution ◽  
Real Time ◽  
Chemical Shifts ◽  
Coupling Constants ◽  
Scalar Coupling

The High Resolution NMR Spectra of Pesticides. II. The DDT-Type Compounds

1969 ◽  
Vol 52 (5) ◽  
pp. 1074-1092 ◽  
Author(s):  
L H Keith ◽  
A L Alford ◽  
A W Garrison
Keyword(s):  
Nuclear Magnetic Resonance ◽  
High Resolution ◽  
Nmr Spectra ◽  
Chemical Shifts ◽  
Coupling Constants ◽  
Aromatic Rings ◽  
Nuclear Magnetic Resonance Spectra ◽  
High Resolution Nmr ◽  
Related Compounds ◽  
Deshielding Effect

Abstract The high resolution nuclear magnetic resonance spectra of the DDT class of pesticides and related compounds are discussed, including a study of the resonances of the aromatic protons as they are affected by various substiluents. The CCl3 moiety on the α-carbon strongly deshields the ortho protons on the aromatic rings, and this deshielding effect is greatly enhanced by substitution of a chlorine ortho rather than para on the aromatic ring. These deshielding effects are explained by a consideration of the electronegativity of the substituents and the stereochemistry of the molecule. The chemical shifts and coupling constants are tabulated.

THE ANALYSIS OF NUCLEAR MAGNETIC RESONANCE SPECTRA: III. PYRIDINE AND DEUTERATED PYRIDINES

1957 ◽  
Vol 35 (12) ◽  
pp. 1487-1495 ◽  
Author(s):  
W. G. Schneider ◽  
H. J. Bernstein ◽  
J. A. Pople
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
High Resolution ◽  
Chemical Shifts ◽  
Coupling Constants ◽  
Spin Coupling ◽  
Calculated Spectrum ◽  
Proton Resonance ◽  
Nuclear Magnetic Resonance Spectra ◽  
Spin Coupling Constants

The proton resonance spectra of pyridine, 2,6-pyridine-d2, 3-pyridine-d1, and 4-pyridine-d1 have been obtained for the pure liquids under conditions of high resolution. The spectra have been analyzed as proton groupings of AB2X2, AB2, perturbed ABX, and B2X2 respectively. The spin-coupling constants obtained from analysis of the simpler spectra of the deuterated molecules were used to suggest trial solutions for the analysis of the complicated AB2X2 spectrum of pyridine. A final set of chemical shifts and spin-coupling constants derived for pyridine give satisfactory agreement between the observed and calculated spectrum.

The High Resolution NMR Spectra of Pesticides. III. The Carbamates

1970 ◽  
Vol 53 (1) ◽  
pp. 157-179 ◽  
Author(s):  
L H Keith ◽  
A L Alford
Keyword(s):  
Nuclear Magnetic Resonance ◽  
High Resolution ◽  
Nmr Spectra ◽  
Chemical Shifts ◽  
Coupling Constants ◽  
Hindered Rotation ◽  
Solvent Dependence ◽  
Nuclear Magnetic Resonance Spectra ◽  
High Resolution Nmr ◽  
Proton Resonances

Abstract The high resolution nuclear magnetic resonance spectra of 35 carbamate pesticides and a major metabolite of one pesticide are discussed. The chemical shifts and coupling constants are tabulated and reproductions of the more complex or unusual spectra are included. A concentration and solvent dependence of both the NH-proton and the NCH3-proton resonances of an N-monosubstituted carbamate is discussed. Hindered rotation is observed in the N,N-dimethylcarbamates, the thiolcarbamates and the dithiocarbamates, but not in the N-methylcarbamates.

Carbon magnetic resonance studies of some phenyl, furyl and thienyl organometallics. Some comments on carbon-metal scalar coupling

1974 ◽  
Vol 27 (2) ◽  
pp. 417 ◽  
Author(s):  
D Doddrell ◽  
KG Lewis ◽  
CE Mulquiney ◽  
W Adcock ◽  
W Kitching ◽  
...  
Keyword(s):  
Chemical Shift ◽  
Chemical Shifts ◽  
Substituent Effects ◽  
Coupling Constants ◽  
Scalar Coupling ◽  
Coupling Constant ◽  
Aryl Substituent ◽  
Magnetic Resonance Studies ◽  
Thienyl Group ◽  
13C Chemical Shift

13C chemical shift variations within a series of phenyl, furyl and thienyl Group IVB organometallics appear to be best understood in terms of the usual alkyl and aryl substituent effects on 13C chemical shifts and not variations in dπ ?pπ metal-aryl interactions. Large changes in 13C-metal scalar coupling constants have been observed suggesting that other factors besides the s-character of the carbon-metal bond is responsible in determining the coupling constant.

High-resolution methods for the measurement of scalar coupling constants

2018 ◽  
Vol 109 ◽  
pp. 135-159 ◽  
Author(s):  
Yanqin Lin ◽  
Qing Zeng ◽  
Liangjie Lin ◽  
Zhong Chen ◽  
Peter B. Barker
Keyword(s):  
High Resolution ◽  
Coupling Constants ◽  
Scalar Coupling

scholarly journals Application of multiplet structure deconvolution to extract scalar coupling constants from 1D NMR spectra

2021 ◽  
Author(s):  
Damien Jeannerat ◽  
Carlos Cobas
Keyword(s):  
Nmr Spectra ◽  
Chemical Shifts ◽  
Second Order ◽  
Coupling Constants ◽  
Scalar Coupling ◽  
Order Effects ◽  
Robust Method ◽  
Multiplet Structure ◽  
First Order ◽  
Coupling Structure

Abstract. Multiplet structure deconvolution provides a robust method to determine the values of the coupling constants in first-order 1D NMR spectra. Functions simplifying the coupling structure for any spins and for doublet with unequal amplitudes were introduced. The chemical shifts of the coupling partners causing mild second-order effects can, in favourable cases, be calculated from the slopes measured in doublet structures. Illustrations demonstrate that deconvolution can straightforwardly analyse multiplet posing difficulties to humans and, in some cases, extract coupling constants from unresolved multiplets.

High-Resolution J-Scaling Nuclear Magnetic Resonance Spectra in Inhomogeneous Fields via Intermolecular Multiple-Quantum Coherences

2009 ◽  
Vol 63 (5) ◽  
pp. 585-590 ◽  
Author(s):  
Yanqin Lin ◽  
Zhong Chen ◽  
Shuhui Cai ◽  
Jianhui Zhong
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
High Resolution ◽  
Chemical Shifts ◽  
Spin Systems ◽  
Coupling Constants ◽  
Multiple Quantum ◽  
J Coupling ◽  
Inhomogeneous Fields ◽  
J Coupling Constants

High-resolution nuclear magnetic resonance (NMR) spectroscopy with information on chemical shifts and J-coupling constants is a sensitive tool for studying physical, chemical, and biological properties of materials at the molecular level. In this paper, a pulse sequence is developed for acquiring high-resolution NMR spectra of liquid samples with J-scaling in inhomogeneous fields via two-dimensional intermolecular multiple-quantum coherence acquisitions. In the resulting one-dimensional projection spectra, apparent J-coupling constants were obtained with a scaling factor theoretically varying from zero (completely decoupled) to infinity relative to the original J-coupling constants while retaining information on chemical shifts, relative peak areas, and multiplet patterns. This allows either an accurate measurement of small J-coupling constants of weakly coupled spin systems or less crowded spectra for spin systems with J-splitting. Experimental observations and simulation results agree with theoretical analysis.

scholarly journals Application of multiplet structure deconvolution to extract scalar coupling constants from 1D nuclear magnetic resonance spectra

2021 ◽  
Vol 2 (2) ◽  
pp. 545-555
Author(s):  
Damien Jeannerat ◽  
Carlos Cobas
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Chemical Shifts ◽  
Coupling Constants ◽  
Scalar Coupling ◽  
Order Effects ◽  
Multiplet Structure ◽  
First Order ◽  
Nuclear Magnetic Resonance Spectra ◽  
Nuclear Magnetic

Abstract. Multiplet structure deconvolution provides a robust method to determine the values of the coupling constants in first-order 1D nuclear magnetic resonance (NMR) spectra. Functions simplifying the coupling structure for partners with spin larger than 1/2 and for doublets with unequal amplitudes were introduced. The chemical shifts of the coupling partners causing mild second-order effects can, in favourable cases, be calculated from the slopes measured in doublet structures. Illustrations demonstrate that deconvolution can straightforwardly analyse multiplet posing difficulties to humans and, in some cases, extract coupling constants from unresolved multiplets.

scholarly journals Differentiation between 6- and 7-Membered Rings Based on Theoretical Calculation of NMR Parameters

2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
Karel D. Klika
Keyword(s):  
Dft Calculation ◽  
Chemical Shifts ◽  
Membered Ring ◽  
Coupling Constants ◽  
Scalar Coupling ◽  
Ring Size ◽  
Broad Application ◽  
Nmr Parameters ◽  
Difficult Cases

The determination of ring size can vary from simple to complex, but the process in difficult cases can be advantageously augmented by DFT calculation of NMR parameters such as the chemical shifts of (), (), and other nuclei as well as pertinent spin-spin (scalar) coupling constants, for example, those between protons (). Differentiation between 6- and 7-membered ring formation in the case of 3,4-dihydro-2H-3-hydroxymethyl-1,4-benzoxazine and 2,3,4,5-tetrahydro-1,5-benzoxazepine-3-ol was evaluated with a view to not only affecting 6- versus 7-membered ring differentiation generally for cases on hand, but also in the case of literature reports where the assigned structures may be in doubt. Thus, the main focus was on the usually reported NMR parameters of , , and and wherein the analysis was found to be highly successful, particularly for , and thus potentially amenable for broad application.

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