Tag Archives: nanoparticles

Recyclable Mesoporous Organosilica Nanoparticles (MSN) for Asymmetric Organocatalysis

2019-10-07Methods & Applications, News from the SeRMN, Our Publicationsasymmetric, catalysis, nanoparticles, sustainable chemistryMiriam

Li, Hao, Míriam Pérez-Trujillo, Xavier Cattoën & Roser Pleixats. 2019. Recyclable Mesoporous Organosilica Nanoparticles Derived from Proline-Valinol Amides for Asymmetric Organocatalysis. ACS Sustainable Chemistry & Engineering 7(17). 14815-14828. DOI: 10.1021/acssuschemeng.9b02838

This is the first report on the obtention of functionalized MSN by a co-condensation procedure with a structurally complex chiral precursor. The functionalized MSN have been characterized by elemental analysis, ²⁹Si and ¹³C CP MAS NMR, transmission electron microscopy, scanning electron microscopy, N₂-sorption measurements, dynamic light scattering, ζ-potential, and powder X-ray diffraction. We have evaluated the activity of these materials as recyclable catalysts in the asymmetric aldol reaction. The use of organosilica nanoparticles reduces the problems of diffusion and low reaction rates encountered with bulk organosilicas.

Solid-state NMR supports a study on Rh nanoparticles

2017-09-18Our PublicationsAromatic, hydrogenation, Ketone, nanoparticles, NHC, Phenol, Pyridine, Quinoline, Rhodium, ssNMR, SurfacePau

NHC-stabilised Rh nanoparticles: Surface study and application in the catalytic hydrogenation of aromatic substrates

F. Martinez-Espinar, P. Blondeau, P. Nolis, B. Chaudret, C. Claver, S. Castillón and C. Godard

DOI: 10.1016/j.jcat.2017.08.010

Highlights

Synthesis and characterisation of small RhNPs stabilised by N-heterocyclic carbenes.
Evidence of the location of the ligands on the faces, edges and apexes of the NPs.
Hydrogenation of aromatic ketones, phenols and N-heteroaromatic substrates.
Tuning of the selectivity as a function of the reaction conditions.
Full reduction of quinoline under mild conditions with total selectivity.

13C{1H} CP-MAS spectra of (a) L, (b) Rh0.4, (c) Rh0.4 + CO and (d) 13C-Rh0.4.

Novel MRI contrast agents: peptide-SPION conjugates

2012-05-21Our Publicationscontrast-agents, molecular imaging, MRI, nanomedicine, nanometric size, nanoparticles, nanotechnology, peptidesSilvia

“Efficient γ-amino-proline-derived cell penetrating peptide-superparamagnetic iron oxide nanoparticle conjugates via aniline-catalyzed oxime chemistry as bimodal imaging nanoagents”, by Cavalli S, Carbajo D, Acosta M, Lope-Piedrafita S, Candiota AP, Arús C, Royo M, Albericio F; Chem. Commun 48 (2012) p. 5322. DOI: 10.1039/C2CC17937G

Recent advances in nanotechnology have offered new opportunities for detection, prevention, and treatment of different diseases. In this respect engineered superparamagnetic iron oxide nanoparticles (SPIONs) represent an advanced tool in nanomedicine because they can be loaded in a multiple and orthogonal way with drugs and probes in order to simultaneously act as molecular imaging agents and drug carriers. Continue reading Novel MRI contrast agents: peptide-SPION conjugates →

HR-MAS: a key technique to study Nanoparticles

2012-01-26Our Publications31P-NMR, aromatic hydrogenation, HRMAS, ligand effect, nanoparticles, ruthenium nanoparticles, surface bound molecules characterizationPau

“Phosphine Stabilized Ruthenium Nanoparticles: the Effect of the Nature of the Ligand in Catalysis” David González-Gálvez, Pau Nolis, Karine Philippot, Bruno Chaudret and Piet W. N. M. van Leeuwen. ACS Catalysis, Volume 2, Pages 317-321, January 2012 DOI: 10.1021/cs200633k

Various ligands not forming monometallic complexes were used for Ru nanoparticle stabilization, enabling the control of size, shape and electronic properties. HRMAS NMR spectroscopy allowed us to study surface-bound molecules, evidencing ligand hydrogenation and decomposition of THF during the RuNP synthesis. Continue reading HR-MAS: a key technique to study Nanoparticles →

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