Tag Archives: HSQMBC

On the interference of JHH modulation in HSQMBC-IPAP and HMBC-IPAP experiments

cover_MRC“On the interference of J(HH) modulation in HSQMBC-IPAP and HMBC-IPAP experiments”, by Josep Saurí and Teodor ParellaMagn. Reson. Chem. 2013. DOI: 10.1002/mrc.3977

The effects of phase signal modulation due to homonuclear proton–proton coupling constants in HSQMBC-IPAP and HMBC-IPAP experiments are experimentally evaluated. An assessment of the reliability ofnJCH measurement from distorted cross-peaks obtained in IPAP versions of HMBC and HSQMBC experiments is presented. Continue reading On the interference of JHH modulation in HSQMBC-IPAP and HMBC-IPAP experiments

CLIP-HSQMBC: Very easy, direct and accurate measurement of nJCH in organic molecules and natural products

CLIP-HSQMBC: Easy measurement of small proton-carbon coupling constants in organic molecules, by Josep Saurí, Teodor Parella and Juan F. Espinosa; Org. Biomol. Chem., 2013, 11, 4473-4478. DOI:10.1039/C3OB40675J

A user-friendly 2D NMR approach denoted as CLIP-HSQMBC is proposed for the very easy, direct and accurate measurement of long-range proton-carbon coupling constants in organic molecules and natural products. The J value can be extracted directly from the analysis of resolved in-phase 1H multiplets that show an additional splitting arising from the proton-carbon coupling. Continue reading CLIP-HSQMBC: Very easy, direct and accurate measurement of nJCH in organic molecules and natural products

J-selHSQMBC: Simultaneous measurement of JHH and two different nJCH using IPAP, J-resolved and E.COSY principles

cover_MRC“Simultaneous measurement of J(HH) and two different nJ(CH) coupling constants from a single multiply-edited 2D cross-peak”, by Josep Saurí and Teodor ParellaMagn. Reson. Chem. 201351, 397-402. DOI: 10.1002/mrc.3960

Three different J-editing methods (IPAP, E.COSY and J-resolved) are implemented in a single NMR experiment to provide spin-state-edited 2D cross-peaks from which simultaneous measurement of different homonuclear and heteronuclear coupling constants can be performed. Continue reading J-selHSQMBC: Simultaneous measurement of JHH and two different nJCH using IPAP, J-resolved and E.COSY principles

P.E.HSQMBC: Simultaneous measurement of proton–proton and proton–carbon coupling constants

“P.E.HSQMBC: Simultaneous measurement of proton–proton and proton–carbon coupling constants” by Josep Saurí, Pau Nolis, Laura Castañar, Albert Virgili and Teodor Parella. Journal of Magnetic Resonance 224 (2012) 101–106. DOI: 10.1016/j.jmr.2012.09.007

A long-range optimized P.E.HSQC experiment, named P.E.HSQMBC, is proposed for the simultaneous measurement of a complete set of homonuclear and heteronuclear coupling constants from a single 2D cross-peak. Continue reading P.E.HSQMBC: Simultaneous measurement of proton–proton and proton–carbon coupling constants

HSQMBC-COSY: Measurement of the sign and the magnitude of long-range proton-carbon coupling constants

“Efficient measurement of the sign and the magnitude of long-range proton-carbon coupling constants from a spin-state-selective HSQMBC-COSY experiment”, by Josep Saurí and Teodor Parella; Magn. Reson. Chem. 2012, 50, 717-721. DOI:10.1002/mrc.3867

A spin-state-selective HSQMBC-COSY experiment is proposed to measure the sign and  the magnitude of long-range proton-carbon coupling constants (nJ(CH); n>1) either for protonated and for non-protonated carbons in small molecules. Continue reading HSQMBC-COSY: Measurement of the sign and the magnitude of long-range proton-carbon coupling constants

Presentations to the Ibero-American NMR & GERMN Bienal & Iberian NMR joint meeting

Next week several SeRMN members will present our research work at the IV Ibero-American NMR – VI GERMN Bienal – III Iberian NMR joint meeting that will take place in Aveiro (Portugal) from 25th to 28th September. Find below a summary of our contributions.

Continue reading Presentations to the Ibero-American NMR & GERMN Bienal & Iberian NMR joint meeting

Accurate measurement of small heteronuclear coupling constants from pure-phase α/β HSQMBC cross-peaks

“Accurate measurement of small heteronuclear coupling constants from pure-phase α/β HSQMBC, by Sergi Gil, Juan Félix Espinosa and Teodor Parella; Journal of Magnetic Resonance 213, 1, 145-150 (2011). DOI:10.1016/j.jmr.2011.09.036

A simple proton-selective α/β-HSQMBC experiment is proposed for the accurate measurement of long-range proton–carbon coupling constants (nJCH) in small molecules without need for an individualized and time-consuming post-processing fitting procedure. Continue reading Accurate measurement of small heteronuclear coupling constants from pure-phase α/β HSQMBC cross-peaks

Measurement of the magnitude and the sign of small nJCH on protonated and non-protonated carbons

“A definitive NMR solution for the simple and accurate measurement of the magnitude and the sign of small heteronuclear coupling constants on protonated and non-protonated carbons”, by Josep Saurí, Juan Félix Espinosa and Teodor ParellaAngew. Chem. Int. Ed. (2012) DOI: 10.1002/anie.201108959

The measurement of long-range proton carbon coupling constants in natural-abundance molecules has always been a tranding topic for the NMR community. Despite the extensive number of NMR techniques that have been developed, there are still remain two unsolved problems pertaining to non-protonated carbons, namely, a) and accurate measurement of very small coupling constants (less than 2-3 Hz) , and b) the absence of a general and robust approach to determine the sign of the coupling. Continue reading Measurement of the magnitude and the sign of small nJCH on protonated and non-protonated carbons

A new way to measure small proton-carbon coupling constants

About this Journal“IPAP–HSQMBC: Measurement of long-range heteronuclear coupling constants from spin-state selective multiplets”, by Sergi Gil, Juan Félix Espinosa and Teodor ParellaJournal of Magnetic Resonance, 207, 312-321 (2010). DOI: 10.1016/j.jmr.2010.09.017

A new NMR approach is proposed for the measurement of long-range heteronuclear coupling constants (nJXH,n > 1) in natural abundance molecules. Two complementary in-phase (IP) and anti-phase (AP) data are separately recorded from a modified HSQMBC experiment and then added/subtracted to provide spin-state-selective α/β–HSQMBC spectra. Continue reading A new way to measure small proton-carbon coupling constants