All posts by Pau

Simultaneous multi-slice excitation in Spatially encoded NMR experiments

cover“Simultaneous multi-slice excitation in Spatially encoded NMR experiments” by Laura Castañar, Pau Nolis, Albert Virgili and Teodor Parella. Chem. Eur. J. 2013, 19, 15472–1547. DOI: 10.1002/chem.201303272

multiple-sliceA novel strategy to enhance the experimental sensitivity in spatially encoded NMR experiments has been developed. Continue reading Simultaneous multi-slice excitation in Spatially encoded NMR experiments

Efficient and fast sign-sensitive determination of heteronuclear coupling constants

“Efficient and fast sign-sensitive determination of heteronuclear coupling constants” by Josep Saurí, Pau Nolis and Teodor ParellaJournal 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: Continue reading Efficient and fast sign-sensitive determination of heteronuclear coupling constants

NaAlH4 confined in Ordered Mesoporous Carbon

hydrogen_energyNaAlH4 confined in Ordered Mesoporous Carbon

Bonatto, C.; Lindemann, I.; Nolis, P.; KieBling, A.; Baró, M. D.; Klose, M.; Giebler, L.; Rellinghaus, B.; Eckert, J.; Schultz, L.; Gutfleisch, O.

In this paper we performed a comprehensive investigation of the structural and sorption properties of a 40 wt. % NaAlH4 confined in a ordered mesoporous carbon (OMC, i.e. CMK-3) by means of X-ray diffraction (XRD), transmission electron microscopy (TEM), 23Na{1H} and 27Al{1H} solid-state magic angle spinning-nuclear magnetic resonance (MAS-NMR).

This study evidences a remarkable improvement of the sorption kinetics of NaAlH4 due to its existence in nanometer size within the OMC. The pressure composition isotherm (PCI) analysis (for the re-absorption step) of the nanoconfined NaAlH4 would suggest an alteration of its equilibrium thermodynamic properties.

13hydrogen_energy_fig4

Gelation process followed by NMR

Journal cover: Organic & Biomolecular ChemistryLow-molecular-weight gelators consisting of hybrid cyclobutane-based peptides, by Sergi Celis, Pau Nolis, Ona Illa, Vicenç Branchadell, Rosa M. Ortuño, Organic & Biomolecular Chemistry 2013, 11, 2839 DOI: 10.1039/c3ob27347d

Some hybrid tetrapeptides consisting of (1R,2S)-2-aminocyclobutane-1-carboxylic acid and glycine, β-alanine, or γ-aminobutyric acid (GABA) joined in alternation, compounds 1–3, respectively, have been investigated to gain information on the non-covalent interactions responsible for their self-assembly to form ordered aggregates, as well as on parameters such as their morphology and size. All three peptides formed nice gels in many organic solvents and significant difference in their behaviour was not observed. Continue reading Gelation process followed by NMR

NMR confirms cysteine labelling with SFB in peptides

issue 1 - RSC Advances_2012.indd“Efficient cysteine labelling of peptides with N-succinimidyl 4-[18F]fluorobenzoate: stability study and in vivo biodistribution in rats by positron emission tomography ( PET)” by Santiago Rojas, Pau Nolis, Juan D. Gispert, Jan Spengler, Fernando Albericio, José R. Herance, Sergio Abad.  RSC Advances. 2013. DOI: 10.1039/C3RA40754C

A rapid and high-yielding cysteine labelling of peptides has been observed with the specific labelling agent for amines, N-succinimidyl 4-[18F]fluorobenzoate ([18F]SFB). Interestingly, NMR demonstrates that conjugation of the 4-fluorobenzoyl (FB) moiety is selectively achieved through a cysteine (Cys) thiol of the peptides with high yield (>80%) in short time (<5 min), while for a Cys amino acid derivative, a slow process has been observed. Continue reading NMR confirms cysteine labelling with SFB in peptides

Conformational Bias of Several Types of γ-Peptides

EurJoc“The Role of the Chiral cis-1,3-Disubstituted 2,2-Dimethylcyclobutane Motif in the Conformational Bias of Several Types of γ-Peptides”  by Jordi Aguilera, Juan A. Cobos, Raquel Gutiérrez-Abad, Carles Acosta, Pau Nolis, Ona Illa, Rosa M. Ortuño. Eur.  J. Org. Chem. 2013 (early view). DOI: 10.1002/ejoc.201300066

Three series of new γ-peptides have been synthesized by starting from conveniently protected cis-3-amino-2,2-dimethylcyclobutane-1-carboxylic acid derivatives. The first series is constructed with only one enantiomer of this γ-amino acid, whereas in the second one both enantiomeric cyclobutane residues are joined in alternating fashion. Continue reading Conformational Bias of Several Types of γ-Peptides

Additives on the Ca(BH) system

jpccck_v116i051.indd“Chemical State, Distribution and Role of Ti- and Nb-Based Additives on the Ca(BH4)2 System” by Christian Bonatto Minella, Eva Pellicer, Emma Rossinyol, Fahim Karini, Claudio Pistidda,Sebastiano Garroni, Chiara Milanese, Pau Nolis, Maria Dolors Baró, Oliver Gutfleisch, Klaus Pranzas, Andreas Schreyer, Thomas Klassen, Rüdiger Bormann and Martin Dornheim. The Journal of Physical Chemistry C. 117:4394-4403 (2013). DOI: 10.1021/jp3116275

Light metal tetrahydroborates are regarded as promising materials for solid state hydrogen storage. Due to both a high gravimetric hydrogen capacity of 11.5 wt. % and an ideal de-hydrogenation enthalpy of 32 kJ mol-1 H2, Ca(BH4)2 is considered to be one of the most interesting compounds in this class of materials. In this work, a comprehensive investigation of the effect of different selected additives (TiF4, NbF5, Ti-isopropoxide and CaF2) on the reversible hydrogenation reaction of calcium borohydride is presented combining different investigation techniques.  Continue reading Additives on the Ca(BH) system

Ca(BH4)2 + MgH2: Desorption Reaction

jpccck_v117i005.indd“Ca(BH4)2 + MgH2: Desorption Reaction and Role of Mg on its Reversibility” by Christian Bonatto Minella, Claudio Pistidda, Sebastiano Garroni, Pau Nolis, Maria Dolors Baró, Oliver Gutfleisch, Thomas Klassen, Rüdiger Bormann, and Martin Dornheim. The Journal of Physical Chemistry C. 117:3846-3852 (2013). DOI: 10.1021/jp312271s

The Ca(BH4)2-MgH2 composite system represents a promising candidate for mobile hydrogen storage due to a 10.5 wt. % theoretical hydrogen storage capacity and an estimated equilibrium temperature lower than 160 °C. For this system, the reversibility was achieved without further addition of additives. Continue reading Ca(BH4)2 + MgH2: Desorption Reaction

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