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 (nJCH) 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 nJCH 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.
Access to experimentally infeasible spectra by pure-shift NMR covariance. André Fredi, Pau Nolis, Carlos Cobas and Teodor Parella. Journal of Magnetic Resonance, Volume 270, September 2016, Pages 161-168. DOI: 10.1016/j.jmr.2016.07.010
Abstract: Covariance processing is a versatile processing tool to generate synthetic NMR spectral representations without the need to acquire time-consuming experimental datasets. Here we show that even experimentally prohibited NMR spectra can be reconstructed by introducing key features of a reference 1D CHn-edited spectrum into standard 2D spectra. This general procedure is illustrated with the calculation of experimentally infeasible multiplicity-edited pure-shift NMR spectra of some very popular homonuclear (ME-psCOSY and ME-psTOCSY) and heteronuclear (ME-psHSQC-TOCSY and ME-psHMBC) experiments.
Continue reading Access to experimentally infeasible spectra by pure-shift NMR covariance
Title: Exploring the use of Generalized Indirect Covariance to Reconstruct Pure shift NMR Spectra: Current Pros and Cons.
Authors: André Fredi, Pau Nolis, Carlos Cobas, Gary E. Martin and Teodor Parella.
ABSTRACT: The current pros and cons of a processing protocol to generate pure chemical shift NMR spectra using Generalized Indirect Covariance are presented and discussed. The transformation of any standard 2D homonuclear and heteronuclear spectrum to its pure shift counterpart by using a reference DIAG spectrum is described. Reconstructed pure shift NMR spectra of NOESY, HSQC, HSQC-TOCSY and HSQMBC experiments are reported for the target molecule strychnine.
Continue reading Exploring the use of Generalized Indirect Covariance to Reconstruct Pure shift NMR Spectra: Current Pros and Cons.
Some of our last research works has been presented by Núria Marcó at the annual meeting of the SmallMolecule NMR Conference (SMASH) that has been taken place in Baveno (Italy) from 20thto 24thSeptember 2015.
Find below a summary of our contributions.
Continue reading SeRMN at the SMASH NMR 2015 Conference
“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: http://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 Efficient and fast sign-sensitive determination of heteronuclear coupling constants