Storage properties of the Li-N-H system

hydrogen_energy“Role of aluminum chloride on the reversible hydrogen storage properties of the Li-N-H system”

Fernández, L.; Garroni, S.; Larochette, P.; Nolis, P.; Mulas, G.; Enzo, S.; Baró, M.D.; Gennari, F. International Journal of Hydrogen Energy, IN PRESS 2015 doi:10.1016/j.ijhydene.2015.08.030

 In order to understand the role of AlCl3 addition on the Li–N–H system, we have systematically investigated the hydrogen sorption kinetics and the reactions between LiNH2–LiH and AlCl3 additive with a multitechnique approach involving differential scanning calorimetry (DSC), hydrogen volumetric measurements, X-ray powder diffraction (XRPD), Fourier transform infrared analysis (FTIR) and solid-state nuclear magnetic resonance (NMR). Different interactions were identified as a function of the amount of added AlCl3. For low AlCl3 addition (0.03 mol), the Al3+ is incorporated into the interstitial sites by the LiNH2 structure. When AlCl3 amount increased (0.08 and 0.13 mol), the formation of new amide-chloride phases were detected by XRPD and indexed with cubic and hexagonal Li–Al–N–H–Cl geometries. Occurrence of such new phases was also confirmed by FTIR and NMR. The formation of these new Li–Al–N–H–Cl phases modifies the kinetics as well as the thermodynamic behavior of the original Li–N–H system. Interesting, in all AlCl3-doped composites, hydrogen was stored reversibly with faster sorption kinetics than un-doped Li–N–H system and with a significant reduction of NH3 emission. This improvement can be associated with the Al3+ incorporation into LiNH2 that promotes the migration of Li+, while for high AlCl3 doping, the formation of new phases Li–Al–N–H–Cl also weakens the N–H bond.

Microsoft Word - Role of aluminum chloride_with Figures_final_Ju

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

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

Presentación1

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.

Several 1H homodecoupled NMR experiments have been developed along this doctoral thesis. Most of them are based on the Homodecoupled Band-Selective (HOBS) experiment through which it is possible to obtain homodecoupled NMR spectra with full sensitivity. HOBS methods offer a powerful and simple way to obtain high-resolved 1D and 2D NMR spectra, as efficiently demonstrated for the accurate, simple and direct measurement of T1/T2 relaxation times in overlapped regions, the determination of heteronuclear coupling constants from simplified multiplets, the determination of very small chemical shift differences with success application in enantiodifferentation studies or the analysis of highly complex mixtures. In addition, the concept of ultra-high-resolution NMR spectroscopy has been tested by combining several resolution-enhanced techniques into a single NMR experiment.

On the other hand, for many years the measurement and practical use of coupling constants have been a timely topic but there are still a number of unresolved issues. Along this doctoral thesis a suite of robust HSQC and HSQMBC experiments have been developed which provide accurate and precise measurements of couplings constants through simple and direct analysis of cross-peaks without involving complex post-processing data manipulation.

Useful Links: Pulse Programs and Data Set Examples

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

Title: cover7Disentangling 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.

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References:

 

Pulse Programs Code for Bruker:

Data set Example:

 

Warming differentially influences the effects of drought on stoichiometry and metabolomics in shoots and roots

“Warming differentially influences the effects of drought on stoichiometry and metabolomics in shoots and roots” by Albert Gargallo-Garriga, Jordi Sardans, Míriam Pérez-Trujillo, Michal Oravec,Otmar Urban, Anke Jentsch, Juergen Kreyling, Carl Beierkuhnlein Teodor Parella and Josep Peñuelas. New Phytologist. March 2015. DOI: 10.1111/nph.13377

Plants in natural environments are increasingly being subjected to a combination of abiotic stresses, such as drought and warming, in many regions. The effects of each stress and the combination of stresses on the functioning of shoots and roots have been studied extensively, but little is known about the simultaneous metabolome responses of the different organs of the plant to different stresses acting at once. We studied the shift in metabolism and elemental composition of shoots and roots of two perennial grasses, Holcus lanatus and Alopecurus pratensis, in response to simultaneous drought and warming.

These species responded differently to individual and simultaneous stresses. These responses were even opposite in roots and shoots. In plants exposed to simultaneous drought and warming, terpenesSin título, catechin and indole acetic acid accumulated in shoots, whereas amino acids, quinic acid, nitrogenous bases, the osmoprotectants choline and glycine betaine, and elements involved in growth (nitrogen, phosphorus and potassium) accumulated in roots. Under drought, warming further increased the allocation of primary metabolic activity to roots and changed the composition of secondary metabolites in shoots. These results highlight the plasticity of plant metabolomes and stoichiometry, and the different complementary responses of shoots and roots to complex environmental conditions.

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

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

Presentación1

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.

 

Publication 1:

cover1Title: Simultaneous multi-slice excitation in spatially encoded NMR experiments.
Authors: L. Castañar, P. Nolis, A. Virgili and T. Parella.
Reference: Chem. Eur. J., 2013, 19, 15472-15475.
DOI: 10.1002/chem.201303272

 

Pulse programs code for Bruker:

Data set example

Java script for multi-offset calculation and examples

 

 

Publication 2:

cover2Title: Full sensitivity and enhanced resolution in homodecoupled band-selective NMR experiments.
Authors: L. Castañar, P. Nolis, A. Virgili and T. Parella.
Reference: Chem. Eur. J., 2013, 19, 17283-17286.
DOI: 10.1002/chem.201303235

 

Pulse Programs Code for Bruker:

Data set Example:

 

Publication 3:

cover3Title: Measurement of T1/T2 relaxation times in overlapped regions from homodecoupled 1H singlet signals.
Authors: L. Castañar, P. Nolis, A. Virgili and T. Parella.
Reference: J. Magn. Reson., 2014, 244, 30-35.
DOI: 10.1016/j.jmr.2014.04.003

 

Pulse program code for Bruker:

Data set example:

 

 

Publication 4:

cover4Title: Enantiodifferentiation through frequency-selective pure-shift 1H Nuclear Magnetic Resonance spectroscopy.
Authors: L. Castañar, M. Pérez-Trujillo, P. Nolis, E. Monteagudo, A. Virgili and T. Parella.
Reference: ChemPhysChem., 2014, 15, 854-857.
DOI: 10.1002/cphc.201301130

Pulse program code for Bruker:

Data set example

 

 

Publication 5:

Cover5Title: Simultaneous 1H and 13C NMR enantiodifferentiation from highly-resolved pure shift HSQC spectra.
Authors: M. Pérez-Trujillo, L. Castañar, E. Monteagudo, L. T. Kuhn, P. Nolis, A. Virgili, R. T. Williamson and T. Parella.
Reference: Chem. Comm., 2014, 50, 10214-10217.
DOI: 10.1039/C4CC04077E

 

Pulse program code for Bruker:

 Data set example

 

 

Publication 6:

cover6Title: Implementing homo- and heterodecoupling in region-selective HSQMBC experiments.
Authors: L. Castañar, J. Saurí, P. Nolis, A. Virgili and T. Parella
Reference: J. Magn. Reson., 2014, 238, 63-69.
DOI:10.1016/j.jmr.2013.10.022

 

Pulse Programs Code for Bruker:

Data set Example:

 

 

Publication 7:

cover7Title: 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

 

Pulse Programs Code for Bruker:

Data set Example:

 

 

Publication 8:

cover8Title: Pure in-phase heteronuclear correlation NMR experiments.
Authors: L. Castañar, J. Saurí, R. T. Williamson, A. Virgili and T. Parella.
Reference: Angew. Chem. Intl. Ed., 2014, 53, 8379-8382.
DOI: 10.1002/anie.201404136

 

 Pulse program code for Bruker:

Data set example:

 

Publication 9:

cover9Title: Suppression of phase and amplitude JHH modulations in HSQC experiments.
Authors: L. Castañar, E. Sistaré, A. Virgili, R. T. Williamson and T. Parella.
Reference: Magn. Reson. Chem., 2015, 53, 115-119.
DOI: 10.1002/mrc.4149

Pulse Program Code for Bruker:

Data set Example:

 

Publication 10:

cover10Title: Recent advances in small molecule NMR: Improved HSQC and HSQMBC experiments.
Authors: L. Castañar and T. Parella.
Reference: Annu. Rep. NMR Spectrosc., 2015, 84, 163-232.
DOI: 10.1016/bs.arnmr.2014.10.004

 

 

 

APPENDIX

REFERENCE: Josep Sauri PhD thesis

Publication 11:

cover11Title: P.E.HSQMBC: Simultaneous measurement of proton-proton and proton-carbon coupling constants
Authors: J. Saurí, P. Nolis, L. Castañar, A. Virgili and T. Parella.
Reference: J. Magn. Reson., 2012, 224, 101-16.
DOI: 10.1016/j.jmr.2012.09.007

 

Pulse Program Code for Bruker:

Data set Example:

 

Publication 12:

cover12Title: Straightforward measurement of individual 1JCH and 2JHH in diastereotopic CH2 groups
Authors: J. Saurí, L. Castañar, P. Nolis,  A. Virgili and T. Parella.
Reference: J. Magn. Reson., 2014, 242, 33-40.
DOI: 10.1016/j.jmr.2014.02.003

 

 Pulse Program Code for Bruker:

Data set Example:

 

Publication 13:

cover13Title: Broadband 1H homodecoupled NMR experiments: recent developments, methods and applications
Authors: L. Castañar and T. Parella.
Reference: Mag. Reson. Chem., 2015, 53, 399-426.
DOI: 10.1002/mrc.4238

Laura Castañar receives award at ENC 2015

Laura CastañarAward to Laura Castañar at the 56th ENC held in Asilomar from 19th to 24th April 2015. was honoured at the 56th 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.

The ENC Ritchey Travel Award to advanced Ph.D. students was established to honor William M. Ritchey, who was Professor Emeritus of Chemistry and Macromolecular Science at Case Western Reserve University and founder of the ENC. Professor William Ritchey founded the ENC in 1960 when he organized a rather informal meeting to discuss experimental problems with early nmr spectrometer and «we decided to meet again the next year and possibly a few more times and to keep our focus on experimental aspects of NMR.» The areas of the Award are to reflect Professor Ritchey’s broad interests in the development and application of NMR to chemical and material sciences.

As part of the award, Laura gave the oral presentation entitled “HOBS: Broadband Homonuclear Decoupled Band-Selective NMR Experiments with Full Sensitivity” in which she explained a novel NMR approach for recording broadband HOmodecoupled Band-Selective (HOBS) NMR spectra with full sensitivity. The HOBS technique allows recording fully homodecoupled singlet signals from chosen parts of the 1H spectrum without loss of sensitivity.

Saurí, a former Ph.D. student at SeRMN currently pursuing a postdoc at Merck Research Laboratories.
Laura shows her diploma of the ENC Ritchey Travel Award. Next to her is Josep Saurí, a former Ph.D. student at SeRMN currently working as postdoc researcher at Merck Research Laboratories.

She also described the straightforward implementation of the HOBS technique for a number of homo and heteronuclear multidimensional experiments (e.g. HOBS-TOCSY, HOBS-HSQC, HOBS-HSQMBC, and more) and she demonstrated that this technique had an ample range of practical applications like the direct measurement of nJCH, the determination of T1 and T2 NMR relaxation times, and enantiodifferentiation studies, among other.

Laura has been working as a Ph.D. candidate at the Department of Chemistry and SeRMN under the co-direction of Dr. Albert Virgili and Dr. Teodor Parella since Sept 2012, when she enrolled in the Department of Chemistry doctoral program at Universitat Autònoma de Barcelona with a fellowship from UAB. She is currently in her third year and expects to defend the doctoral thesis before the summer holiday. You can read about her work on this blog.

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

MRC_teo copy“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 JHH 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. A detailed discussion about the most relevant practical aspects in terms of pulse sequence design, selectivity, sensitivity, spectral resolution and performance is provided. Finally, the implementation of the different reported strategies into traditional 1D and 2D NMR experiments is described while several practical applications are also reviewed.

Presentación1

Ultra high-resolution HSQC

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 Resolved HSQCportada

SeRMN presentation at the 56th ENC 2015 Conference

Imagen1

During these days takes place the 56th 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”

Abstract: Recently, a novel NMR approach for recording broadband HOmodecoupled Band-Selective (HOBS) NMR spectra with full sensitivity has been reported. The HOBS technique is a frequency-selective experiment which affords fully homodecoupled singlet signals in particular areas of the 1H spectrum without sacrificing sensitivity, allowing the fast NMR data acquisition in the same experimental times as regular experiments. Here we present the easy and reliable implementation of the HOBS technique for a number of homo and heteronuclear multidimensional experiments, such as HOBS-TOCSY, HOBS-HSQC, HOBS-HSQMBC, HOBS Inversion-Recovery and HOBS-CPMG-PROJECT. In addition, its practical utility in a wide range of applications, covering the direct measurement of nJCH, the determination of T1 and T2 NMR relaxation times and the enantiodifferentiation studies, among other.

ENC2015_TOC_ Laura Castañar