scholarly journals CSSF-CLIP-HSQMBC: measurement of heteronuclear coupling constants in severely crowded spectral regions

RSC Advances ◽  
2019 ◽  
Vol 9 (62) ◽  
pp. 36082-36087 ◽  
Author(s):  
Aitor Moreno ◽  
Kine Østnes Hansen ◽  
Johan Isaksson
Keyword(s):  
Chemical Shift ◽  
Long Range ◽  
Program Development ◽  
Coupling Constants ◽  
Selective Filtration ◽  
User Friendly ◽  
Heteronuclear Coupling

A new pulse program development, a chemical shift selective filtration clean in-phase HSQMBC (CSSF-CLIP-HSQMBC), is presented for the user-friendly measurement of long-range heteronuclear coupling constants in severely crowded spectral regions.

Measurement of long-range heteronuclear coupling constants

1989 ◽  
Vol 85 (1) ◽  
pp. 111-131 ◽  
Author(s):  
Jeremy J Titman ◽  
David Neuhaus ◽  
James Keeler
Keyword(s):  
Long Range ◽  
Coupling Constants ◽  
Heteronuclear Coupling

SUBSTITUTIONAL AND CONFIGURATIONAL EFFECTS ON CHEMICAL SHIFT IN PYRANOID CARBOHYDRATE DERIVATIVES

1965 ◽  
Vol 43 (7) ◽  
pp. 2059-2070 ◽  
Author(s):  
R. U. Lemieux ◽  
J. D. Stevens
Keyword(s):  
Chemical Shift ◽  
Long Range ◽  
Chemical Shifts ◽  
Coupling Constants ◽  
Equatorial Orientation ◽  
Free Energies ◽  
Bonding Interaction ◽  
Conformational Properties ◽  
Good Agreement ◽  
Shielding Effects

The effects of long-range and virtual long-range coupling on the observed spectra of acetylated hexopyranoses and pentopyranoses are examined. Use is made of both spin decoupling and specific deuteration for the assignment of signals. It is seen that specific solvent effects on chemical shift can be superior to increasing the applied magnetic field for the resolution of the signals of closely related protons. The alteration of virtual long-range coupling effects in these ways can be useful in the diagnosis of spectra. Empirical rules are derived for estimating the long-range shielding effects which occur on changing configurations. It is seen that the inversion of a center can lead to deshielding of axial protons and to shielding of equatorial protons at other centers relative to the chemical shifts observed in reference compounds wherein all the acetoxy groups are in equatorial orientation. The effects in several cases result in equatorial protons giving their signal to higher field than chemically similar but axial protons. The conformational properties of pentopyranose tetraacetates as estimated from chemical shifts and coupling constants are seen to be in good agreement with expectations based on non-bonding interaction free energies. As expected, 2-deoxy-β-D-ribopyranose triacetate has the 1C-conformation when dissolved in chloroform.

A Method for Measurement of Long-Range Heteronuclear Coupling Constants from 2D HMQC Spectra

1996 ◽  
Vol 119 (1) ◽  
pp. 120-124 ◽  
Author(s):  
Dušan Uhrı́n ◽  
Vikram Varma ◽  
Jean-Robert Brisson
Keyword(s):  
Long Range ◽  
Coupling Constants ◽  
Heteronuclear Coupling
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