Tag Archives: proton-carbon coupling constants

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

Master thesis on NMR methods to mesure residual proton-carbon dipolar couplings in small molecules

Last September I defended my Master thesis entitled: “Medida de Acoplamientos Dipolares Residuales en Moléculas Orgánicas”

In recent years the use of Residual Dipolar Couplings (RDCs) has had a huge impact on the structure determination of biological macromolecules by Nuclear Magnetic Resonance (NMR). Its usefulness in determining the structure of small/medium-size organic compounds is increasingly more recognized. Continue reading Master thesis on NMR methods to mesure residual proton-carbon dipolar couplings in small molecules

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

Measurement of long-range proton-carbon coupling constants from pure in-phase 1D multiplets

“Measurement of long-range proton-carbon constants from pure in-phase 1D multiplets”, by Juan F. Espinosa, Paloma Vidal, Teodor Parella and Sergi Gil: Magnetic Resonance in Chemistry 49, 502-507 (2011). DOI:10.1002/mrc.2782

A double-selective variant of the SELINCOR pulse sequence yields 1D proton multiplets that exhibit pure absortive in-phase lineshapes for precise measurement of specific long-range proton-carbon coupling constants in small organic molecules at natural abundance. Continue reading Measurement of long-range proton-carbon coupling constants from pure in-phase 1D multiplets