All posts by Pau

¹¹B-MQMAS Solid State NMR experiment performed on polyaminoborane derivatives

2016-07-09Our Publications11B-NMR, catalysis, Dehydrogenation, MQMAS, polyaminoborane, Rh_catalyst, ssNMRPau

Ammonia Borane Dehydrogenation Promoted by a Pincer-Square-Planar Rhodium(I) Monohydride: A Stepwise Hydrogen Transfer from the Substrate to the Catalyst
Esteruelas, M.A.; Nolis, P.; Oliván, M.; Oñate, M.; Vallribera, A.; Vélez, A. Inorg. Chem., 2016, 55 (14), pp 7176–7181. DOI: 10.1021/acs.inorgchem.6b01216

The pincer d8-monohydride complex RhH-{xant(PiPr2)2} (xant(PiPr2)2 = 9,9-dimethyl-4,5-bis-(diisopropylphosphino)xanthene) promotes the release of 1 equiv of hydrogen from H3BNH3 and H3BNHMe2 with TOF50% values of 3150 and 1725 h−1, to afford [BH2NH2]n and [BH2NMe2]2 and the tandem ammonia borane dehydrogenation−cyclohexene hydrogenation. Continue reading ¹¹B-MQMAS Solid State NMR experiment performed on polyaminoborane derivatives →

Annion binding affinities studied by ¹H-NMR

2016-06-28Our Publicationsamino_acid_derivatives, anion_receptors, bifluoride_anion, binding_affinity, C3-symmetric_podands, NMR_titraionPau

“Synthesis, Selectivity and Structural Study of New C₃-Symmetric Tripodal Amides as Anion Receptors. An Experimental and Theoretical Approach”

Celis, S.; Pi-Boleda, B.; Nolis, P.; Illa, O.; Branchadell, V.; Ortuño, R. Chemistry Select. doi: 10.1002/slct.201600560

Several new nitrilotriacetic acid (NTA) based C₃-symmetric tripodal amides have been synthesized. The NTA branches are alkyl chains or esters derived from amino acids of different length, namely glycine, β-alanine and γ-aminobutyric acid. The behavior of these compounds to entrap different monoanions has been tested revealing that they are good ligands able to form host-guest complexes with the following affinity order: H₂PO₄^– > CH₃CO₂^– > PhCO₂^– > Cl^–, in DMSO. Continue reading Annion binding affinities studied by ¹H-NMR →

Storage properties of the Li-N-H system

2015-09-01Our Publications27Al-NMR, 7Li-NMR, hydrogen-Storage, solid-state nmrPau

“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). Continue reading Storage properties of the Li-N-H system →

Automation in ¹J_CH measurements from Pure Shift NMR experiments

2014-11-26Our Research, Seminarshomonuclear decoupling, java_applet, Jres, proton-carbon coupling constants, software_developmentPau

SeRMN seminar

Date: Thursday 27th November, 2014
Hour: 12 am
Location: SeRMN, Facultats de Ciències i Biociències, C2/-135
Speaker: Dr. Pau Nolis, SeRMN

A preliminary version of an applet that performs the authomatic measurement of 1J(CH) couplings from homodecoupled iINEPT-Jres HSQC experiment will be presented. Continue reading Automation in ¹J_CH measurements from Pure Shift NMR experiments →

Confining light metal hydrides in micro- or mesoporous scaffolds

2014-03-01Our Publications27Al-NMR, 7Li-NMR, hydrides, solid-state nmrPau

“Unusual Oxidation Behavior of Light Metal Hydride by Tetrahydrofurane Solvent Molecules Confined in Ordered
Mesoporous Carbon” Klose, M.; Lindemann, I.; Minella, C.; Pinkert, K.; Zier, M.; Giebeler, L.; Nolis, P.; Baro, M.; Oswald, S.; Gutfleisch, O.; Ehrenberg, H.; Eckert, J. Journal Of Materials Research, 2014, 29, 55-63 DOI:10.1557/jmr.2013.199

Confining light metal hydrides in micro- or mesoporous scaffolds is considered to be a promising way to overcome the existing challenges for these materials, e.g. their application in hydrogen storage. Different techniques exist which allow us to homogeneously fill pores of a host matrix with the respective hydride, thus yielding well defined composite materials. Continue reading Confining light metal hydrides in micro- or mesoporous scaffolds →

Structural evolution upon decomposition of the LiAlH₄+LiBH₄ system

2013-12-11Our Publications11B-NMR, 27Al-NMR, 7Li-NMR, borohydrides, hydrogen-Storage, solid-state nmrPau

Structural evolution upon decomposition of the LiAlH₄+LiBH₄ system. S. Soru, A. Taras, C. Pistiddb, C. Milanese, C. Bonatto Minella, E. Masolo, P. Nolis, M. D. Baró, A. Marinic, M. Tolkiehn,M. Dornheim, S. Enzo, G. Mulas, S. Garroni. Journal of Alloys and Compounds 2014, in press. DOI: 10.1016/j.jallcom.2013.12.027

In the present work we focus the attention on the phase structural transformations occurring upon the desorption process of the LiBH₄ + LiAlH₄ system. Continue reading Structural evolution upon decomposition of the LiAlH₄+LiBH₄ system →

NaAlH₄ confined in Ordered Mesoporous Carbon

2013-07-13Our Publications23Na-NMR, 27Al-NMR, hydrides, ordered_mesoporous_carbon, solid-state nmrPau

NaAlH4 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.

Gelation process followed by NMR

2013-06-11Our Publicationschirality, foldamers, gelation, hydrogen-bonds, organogels, peptides, secondary structures, self-assemblyPau

Low-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

2013-05-14Our Publicationspeptides, PET, strucutural characterizationPau

“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

2013-04-15Our Publicationsconformational-study, heterochirality, homochirality, hydrogen-bonds, peptides, peptidomimeticsPau

“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 →

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