Tag Archives: heteronulear coupling constants

Measuring Long-Range Heteronuclear Coupling Constants with Sel-HSQMBC Experiments: A Tutorial

2019-09-13Our Publications, Our Researchheteronulear coupling constants, HSQMBC, HSQMBC-TOCSY, sel-HSQMBCPau

How to measure long‐range proton‐carbon coupling constants from ¹H‐selective HSQMBC experiments, by Josep Saurí, Pau Nolis and Teodor Parella. Magn. Reson. Chem. 2019. Early View, DOI: https://onlinelibrary.wiley.com/doi/10.1002/mrc.4928

Heteronuclear long‐range scalar coupling constants (ⁿJ_CH) are a valuable tool for solving problems in organic chemistry and are especially suited for stereochemical and configurational analyses of small molecules and natural products. This tutorial will focus on the step‐by‐step implementation of several 2D ¹H frequency selective HSQMBC experiments for the easy and accurate measurement of either the magnitude or both the magnitude and the sign of long‐range ⁿJ_CH couplings. The performance of these experiments will be showcased with several scenarios in a range of different experimental conditions.

Bruker pulse program code for selHSQMBC experiments available here.

Bruker pulse program code for selHSQMBC-TOCSY experiment available here.

Strychnine dataset examples available here.

PhD Thesis by Laura Castañar: Pulse Programs and Data Set Examples

2015-05-31Methods & Applications, News from the SeRMN, NMR Events & Courses, Our Publications, Our Researchaligned-media, coupling-constants, enantiodifferentiation, enhanced resolution, full sensitivity, heteronulear coupling constants, HOBS, HOBS-HSQC, HOBS-HSQC-TOCSY, HOBS-HSQMBC, HOBS-TOCSY, homodecoupling, homonuclear decoupling, HSQC, HSQMBC, J-resolved, multi-slice selection, multiple frequency pulses, NUS, one-bond proton-carbon coupling constants, perfect HSQC, PhD Thesis, PIP experiments, proton-carbon coupling constants, proton-proton coupling constants, pure in-phase signals, Pure shift, quantitative nmr, RDCs, Relaxation times, residual dipolar couplings, resolution enhancement, SAPS-HSQC, sensitivity enhancement, sign of coupling constants, spectral aliasing, T1-relaxation, T2-relaxation, two-bonds proton-proton coupling constantsLaura

Development and application of modern pure shift NMR techniques and improved HSQC/HSQMBC experiments

In the following links one can find Data Set Examples of each Publication presented in the Thesis Work, as well as the corresponding Pulse Program Code for Bruker. All 2D spectra have been previously phased and 2ii, 2ir, and 2ri files removed, otherwise data sets would be too big. Continue reading PhD Thesis by Laura Castañar: Pulse Programs and Data Set Examples →

Review – Pure shift NMR experiments: recent developments, methods and applications

2015-05-02Methods & Applications, NMR Bibliography, Our Publications, Our Researchenantiodifferentiation, enhanced resolution, full sensitivity, heteronulear coupling constants, HOBS, HOBS-HSQC, HOBS-HSQMBC, HOBS-TOCSY, homodecoupling, homonuclear decoupling, Pure shift, Relaxation times, resolution enhancement, review, SAPS-HSQC, sensitivity enhancement, T1-relaxation, T2-relaxationLaura

“Broadband ¹H homodecoupled NMR experiments: recent developments, methods and applications” by Laura Castañar and Teodor Parella. Magnetic Resonance in Chemistry, 2015. DOI: 10.1002/mrc.4238

In recent years, a great interest in the development of new broadband ¹H homonuclear decoupled techniques providing simplified J_HH multiplet patterns has emerged again in the field of small molecule NMR. The resulting highly resolved ¹H NMR spectra display resonances as collapsed singlets, therefore minimizing signal overlap and expediting spectral analysis. This review aims at presenting the most recent advances in pure shift NMR spectroscopy, with a particular emphasis to the Zangger–Sterk experiment. Continue reading Review – Pure shift NMR experiments: recent developments, methods and applications →

Ultra high-resolution HSQC

2015-04-29Our Research, Seminarsheteronulear coupling constants, HSQC, spectral aliasingNúria

SeRMN seminar

Date: Thursday 7th May, 2015
Hour: 15:30
Location: SeRMN, Facultats de Ciències i Biociències, C2/-135
Speaker: Núria Marcó, SeRMN PhD Student

The content of our recently published article entitled “Ultra high-resolution HSQC: Application to the efficient and accurate measurement of heteronuclear coupling constants” will be explained and discussed briefly. A rapid NMR data acquisition strategy in terms of enhanced resolution per time unit for the simple and efficient determination of multiple coupling constants is described. The use of 13C spectral aliasing combined with broadband 1H homodecoupling allows accurate measurements from ultra high resolved 2D HSQC cross-peaks.

Ultra high-resolution HSQC: Application to the efficient and accurate measurement of heteronuclear coupling constants

2015-01-16Our Publicationsheteronulear coupling constants, HSQC, spectral aliasingNúria

“Ultra high-resolution HSQC: Application to the efficient and accurate measurement of heteronuclear coupling constants” by Núria Marcó, Andre Fredi and Teodor Parella. Chemical Communications 2015, 51:3262-3265. DOI: 10.1039/C4CC10279G

A rapid NMR data acquisition strategy in terms of enhanced resolution per time unit for the simple and efficient determination of multiple coupling constants is described. The use of 13C spectral aliasing combined with broadband 1H homodecoupling allows accurate measurements from ultra high resolved 2D HSQC cross-peaks.

Pulse Program Code for Bruker:

SAPS-HSQC (see post “Simultaneous 1H and 13C NMR enantiodifferentation from highly-resolved pure shift HSQC spectra” for details).

Data set Example:

Fluoropyridine

Perfect-HSQC experiments: pure in-phase spectra

2014-10-04Methods & Applications, Our Publications, Our Researchheteronulear coupling constants, HSQC, one-bond proton-carbon coupling constants, perfect HSQC, proton-proton coupling constants, pure in-phase signalsLaura

“Suppresión of phase and amplitude J_HH modulations in HSQC experiments” by Laura Castañar, Eduard Sistaré, Albert Virgili, Robert Thomas Williamson and Teodor Parella. Magnetic Resonance in Chemistry, 2014 , 53:115-119. DOI: 10.1002/mrc.4149

The amplitude and the phase of cross peaks in conventional 2D HSQC experiments are modulated by both proton–proton, J_HH, and proton–carbon, ¹J_CH, coupling constants. It is shown by spectral simulation and experimentally that J_HH interferences are suppressed in a novel perfect-HSQC pulse scheme that incorporates perfect-echo INEPT periods. Continue reading Perfect-HSQC experiments: pure in-phase spectra →

Pure In-Phase Heteronuclear Correlation NMR Experiments

2014-06-27Methods & Applications, Our Publications, Our Researchheteronulear coupling constants, HSQC, HSQMBC, IPAP, PIP experiments, proton-carbon coupling constants, proton-proton coupling constantsLaura

“Pure In-Phase Heteronuclear Correlation NMR Experiments ” by Laura Castañar, Josep Sauri, Robert Thomas Williamson, Albert Virgili and Teodor Parella. Angew. Chem. Int. Ed. 2014, 53, 8379-8382. DOI: 10.1002/anie.201404136

A general NMR approach to provide pure in-phase (PIP) multiplets in heteronuclear correlation experiments is described. The implementation of a z-filter efficiently suppresses any unwanted anti-phase contributions that usually distort the multiplet pattern of cross-peaks and can make their analysis difficult. Continue reading Pure In-Phase Heteronuclear Correlation NMR Experiments →

Presentations at the EUROMAR 2014 Conference

2014-06-18News from the SeRMN, NMR Events & Courses, Our Researchenantiodifferentiation, EUROMAR, heteronulear coupling constants, HOBS, homonuclear decoupling, NMR Conference, pure-shift NMRLaura

EUROMAR 2014

In a few days several SeRMN members will present our research work at the annual meeting of the European magnetic resonance community EUROMAR 2014 Conference that will take place in Zurich (Switzerland) from 29^thJune to 3^th July. Find below a summary of our contributions. Continue reading Presentations at the EUROMAR 2014 Conference →

PhD Thesis by Josep Saurí: Pulse Programs and Data Set Examples

2014-04-25News from the SeRMN, Our Researchheteronulear coupling constants, pulse programsJosep

In the following links one can find Data Set Examples of each Publication presented in the Thesis Work, as well as the corresponding Pulse Program Code for Bruker. All spectra have been previously phased and 2ii, 2ir, and 2ri files removed, otherwise data sets would be too big. Continue reading PhD Thesis by Josep Saurí: Pulse Programs and Data Set Examples →

Efficient and fast sign-sensitive determination of heteronuclear coupling constants

2013-10-02Methods & Applications, Our Publications, Our Researchheteronulear coupling constants, HSQMBC-TOCSY, IPAP, sign of coupling constantsJosep

“Efﬁcient and fast sign-sensitive determination of heteronuclear coupling constants” by Josep Saurí, Pau Nolis and Teodor Parella. Journal of Magnetic Resonance 236 (2013) 66–69. DOI: https://dx.doi.org/10.1016/j.jmr.2013.08.013

Two complementary 1D NMR approaches for the fast and easy determination of the magnitude and the sign of heteronuclear J(XH) coupling constants are proposed:The Up&Down technique relies on the direct analysis of anti-phase multiplets whereas the Left&Right technique is based on the relative displacement between separate IPAP components.

Continue reading →

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