Tag Archives: HOBS

PhD Thesis: Development and application of modern pure shift NMR techniques and improved HSQC and HSQMBC experiments

2015-07-27Methods & Applications, News from the SeRMN, Our Researchcoupling-constants, enhanced resolution, full sensitivity, HOBS, homonuclear decoupling, HSQC, HSQMBC, perfect HSQC, PhD Thesis, PIP experiments, pure in-phase signals, pure-shift NMR, residual dipolar couplings, SAPS-HSQC, sensitivity enhancementLaura

Last 16^st July 2015 I defended my PhD Thesis entitled: Development and application of modern pure shift NMR techniques and improved HSQC/HSQMBC experiments.

The present doctoral thesis is framed within the Nuclear Magnetic Resonance (NMR) spectroscopy field, more specifically in the design of modern NMR methodologies. The research work carried out is focused on the design and application of new and modern NMR methodologies (i) to perform efficient broadband ¹H homodecoupling in 1D/2D NMR experiments and (ii) to accurately determine homo- and heteronuclear coupling constants in isotropic and anisotropic conditions through improved HSQC and HSQMBC-type experiments. The thesis is presented as a compendium ten (10) publications that have been published in several peer-reviewed international scientific journals as original research papers. Continue reading PhD Thesis: Development and application of modern pure shift NMR techniques and improved HSQC and HSQMBC experiments →

Ultra-high-resolved NMR: Analysis of complex mixtures of compounds with near-identical ¹H and ¹³C NMR spectra

2015-07-20Methods & Applications, Our Publications, Our Researchenhanced resolution, HOBS, HOBS-HSQC, HOBS-HSQC-TOCSY, HOBS-HSQMBC, homodecoupling, homonuclear decoupling, NUS, Pure shift, pure-shift NMR, spectral aliasingLaura

Title: Disentangling complex mixtures of compounds with near-identical ¹H and ¹³C NMR spectra using pure shift NMR.
Authors: L. Castañar, R. Roldán, P. Clapés, A. Virgili and T. Parella.
Reference: Chem. Eur. J., 2015, 21, 7682-7685.
DOI: 10.1002/chem.201500521

Abstract: The thorough analysis of highly complex NMR spectra using pure shift NMR experiments is described. The enhanced spectral resolution obtained from modern 2D HOBS experiments incorporating spectral aliasing in the ¹³C indirect dimension enables the distinction of similar compounds exhibiting near-identical ¹H and ¹³C NMR spectra. It is shown that a complete set of extremely small Δδ(1H) and Δδ(13C) values, even below the natural line width (1 and 5 ppb, respectively), can be simultaneously determined and assigned.

References:

“Full sensitivity and enhanced resolution in homodecoupled band-selective NMR experiments” Chem. Eur. J. 2013, 19, 17283-17286.

“Simultaneous ¹H and ¹³C NMR enantiodifferentiation from highly-resolved pure shift HSQC spectra” Chem. Commun. 2014 50, 10214-10217.

“Implementing homo- and heterodecoupling in region-selective HSQMBC experiments” J. Magn. Reson. 2014, 238, 63-69.

Pulse Programs Code for Bruker:

2D HOBS-HSQC-TOCSY

Data set Example:

Mixture

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 →

Laura Castañar receives award at ENC 2015

2015-05-10News from the SeRMN, Our Researchaward, HOBS, HOBS-HSQC, HOBS-HSQMBC, HOBS-TOCSY, homonuclear decouplingMiquel

Laura Castañar Award to Laura Castañar at the 56th ENC held in Asilomar from 19th to 24th April 2015. was honoured at the 56^th Experimental Nuclear Magnetic Resonance Conference (ENC) with the Ritchey Travel Award for her Ph.D. Thesis research on “Development and application of modern pure shift NMR techniques and improved HSQC/HSQMBC experiments”. The award ceremony took place at the After-Dinner Program in Asilomar Conference Center in Pacific Grove, California, USA, the 23th April, 2015.
Continue reading Laura Castañar receives award at ENC 2015 →

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 →

SeRMN presentation at the 56th ENC 2015 Conference

2015-04-23NMR Events & CoursesENC, HOBS, HOBS-HSQC, HOBS-HSQMBC, HOBS-TOCSY, homodecoupling, NMR Conference, Pure shift, spectral aliasingLaura

During these days takes place the 56^th Experimental Nuclear Magnetic Resonance Conference (ENC) in Asilomar Conference Grounds (Pacific Grove, California, USA) where Laura Castañar presents an Oral Communication entitled “HOBS: Broadband Homonuclear Decoupled Band-Selective NMR Experiments with Full Sensitivity” Continue reading SeRMN presentation at the 56th ENC 2015 Conference →

SeRMN presentations at the 2014 Ibero-American NMR & GERMN Bienal & Iberian NMR meeting

2014-09-15Methods & Applications, NMR Events & Courses, Our Researchchirality, enantiodifferentiation, enhanced resolution, full sensitivity, HOBS, HOBS-TOCSY, homodecoupling, homonuclear decoupling, multipl, pure-shift NMRLaura

Some of our last research work will be presented next week at the VI Ibero-American NMR – VII GERMN Bienal – IV Iberian NMR joint meeting that will take place in Alcalá de Henares, Madrid (Spain) from 22^nd to 25^th September. Find below a summary of our contributions.

Laura Castañar presents an oral communication and a poster entitled “Enantiodifferentiation throgh frequency-selective pure shift ¹H NMR”. NMR-aided discrimination of enantiomers using chiral solvating agents (CSAs) is a well established method to carry out enantiodifferentiation studies. Continue reading SeRMN presentations at the 2014 Ibero-American NMR & GERMN Bienal & Iberian NMR meeting →

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 →

HOBS experiments to measure T₁/T₂ relaxation times in overlapped regions

2014-05-14Methods & Applications, Our Publications, Our Research, Uncategorizedband-selective, CPMG, enhanced resolution, full sensitivity, HOBS, homodecoupling, homonuclear decoupling, Inversion Recovery, PROJECT, pure-shift NMR, Relaxation times, T1-relaxation, T2-relaxationLaura

“Measurement of T₁/T₂ relaxation times in overlapped regions from homodecoupled ¹H singlet signals” by Laura Castañar, Pau Nolis, Albert Virgili and Teodor Parella. Journal of Magnetic Resonance 244 (2014) 30-35. DOI: 10.1016/j.jmr.2014.04.003

The implementation of the HOmodecoupled Band-Selective (HOBS) technique in the conventional Inversion-Recovery and CPMG-based PROJECT experiments is described. The achievement of fully homodecoupled signals allows the distinction of overlapped ¹H resonances with small chemical shift differences. It is shown that the corresponding T₁ and T₂ relaxation times can be individually measured from the resulting singlet lines using conventional exponential curve-fitting methods. Continue reading HOBS experiments to measure T₁/T₂ relaxation times in overlapped regions →

HOBS Applications

2014-03-26Methods & Applications, Our Research, Seminarsenantiodifferentiation, enhanced resolution, full sensitivity, HOBS, HOBS-HSQC, HOBS-HSQMBC, HOBS-TOCSY, homodecoupling, homonuclear decoupling, proton-carbon coupling constants, pure-shift NMRLaura

SeRMN seminar

Date: Friday 28th March, 2014
Hour: 12 am
Location: SeRMN, Facultats de Ciències i Biociències, C2/-135
Speaker: Laura Castañar, SeRMN PhD Student & Teaching Assistant, Dept. of Chemistry.

Several NMR applications using HOmodecouped Band-Selective NMR experiments [1] are proposed. The easy implementation of this HOBS scheme as a general building block into a great variety of multidimensional NMR experiments leads to pure-shift spectra with enhanced resolution and with the maximum attainable sensitivity. In this talk is presented the application of HOBS for measuring direct [1] and long-range [2] heteronuclear coupling constants. Also the use of HOBS experiments to enantiodiscrimination studies are presented [3].

Reference:

[1] “Full sensitivity and enhanced resolution in homodecoupled band-selective NMR experiments” by L. Castañar, P. Nolis, A. Virgili and T. Parella. Chem. Eur. J. 2013, 19, 17283-17286. DOI: 10.1002/chem.201303235

[2] “Implementing homo- and heterodecoupling in region-selective HSQMBC experiments” by Laura Castañar, Josep Sauri, Pau Nolis,Albert Virgili and Teodor Parella. Journal of Magnetic Resonance,2014, 238, 63-69. DOI:10.1016/j.jmr.2013.10.022

[3] “Enantiodifferentiation through Frequency-Selective Pure-Shift 1H Nuclear Magnetic Resonance Spectroscopy” by Laura Castañar, Míriam Pérez-Trujillo, Pau Nolis, Eva Monteagudo , Albert Virgili and Teodor Parella. ChemPhysChem, 2014. DOI: 10.1002/cphc.201301130

Continue reading HOBS Applications →

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