Publications associées à Oxygène 17

Endogenous O-17 Dynamic Nuclear Polarization of Gd-Doped CeO2 from 100 to 370 K

David Lyndon Emsley, Snaedis Björgvinsdóttir, Moreno Lelli, Michael Allan Hope, Georges Guévork Jean-Jacques Menzildjian, Bowen Zhang, Zhuoran Wang

O-17 NMR is an invaluable tool to study the structure and dynamics of oxide materials but remains challenging to apply in many systems. Even with isotopic enrichment, studies of samples with low masses and/or concentrations of the active species, such as t ...

2021

Measurement of Proton Spin Diffusivity in Hydrated Cementitious Solids

David Lyndon Emsley, Brennan James Walder, Federico Maria Paruzzo, Jayasubba Reddy Yarava, Bradley Floyd Chmelka

The study of hydration and crystallization processes involving inorganic oxides is often complicated by poor long-range order and the formation of heterogeneous domains or surface layers. In solid-state NMR, H-1-H-1 spin diffusion analyses can provide info ...

2019

BDPA-Nitroxide Biradicals Tailored for Efficient Dynamic Nuclear Polarization Enhanced Solid-State NMR at Magnetic Fields up to 21.1 T

David Lyndon Emsley, Aaron James Rossini, Dominik Józef Kubicki, Arthur César Pinon, Moreno Lelli, Georges Guévork Jean-Jacques Menzildjian, David Benjamin Roger Antoine Gajan

Dynamic nuclear polarization (DNP) solid-state nuclear magnetic resonance (NMR) has developed into an invaluable tool for the investigation of a wide range of materials. However, the sensitivity gain achieved with many polarizing agents suffers from an unf ...

AMER CHEMICAL SOC2018

Carbazole as Linker for Dinuclear Gadolinium-Based MRI Contrast Agents

Lothar Helm, Bibimaryam Mousavi, Anne-Sophie Chauvin, Loïck Moriggi

Ligands able to complex two gadolinium ions have been synthesized and characterized in view of the ability of the complexes to increase the spin relaxation of water protons. All ligands are based on the heptadentate diethylenetriaminetetraacetic acid (DTTA ...

Wiley-V C H Verlag Gmbh2017

Prototropic Exchange Governs T-1 and T-2 Relaxivities of a Potential MRI Contrast Agent Nanozeolite Gd-LTL with a High pH Responsiveness

Lothar Helm

Aqueous suspensions of lanthanide exchsanged zeolite LTL have been investigated by 1H, 17O NMR, and EPR relaxivity studies. Both the longitudinal and the transverse relaxivity of these Gd3+ loaded materials are strongly pH dependent and therefore, they hav ...

American Chemical Society2015

Challenges in preparing, preserving and detecting para-water in bulk: overcoming proton exchange and other hurdles

Geoffrey Bodenhausen, Aurélien Bornet, Sami Jannin, Jonas Milani, Diego Carnevale, Nicola Salvi, Daniele Mammoli, Roberto Buratto, Estel Canet Martinez

Para-water is an analogue of para-hydrogen, where the two proton spins are in a quantum state that is antisymmetric under permutation, also known as singlet state. The populations of the nuclear spin states in para-water are believed to have long lifetimes ...

Royal Society of Chemistry2015

Single-Molecule-Magnet Behavior in Mononuclear Homoleptic Tetrahedral Uranium(III) Complexes

Marinella Mazzanti, Lucile Sylvie Danielle Chatelain

The magnetic properties of the two uranium coordination compounds, [K(18c6)][U(OSi-((OBu)-Bu-t)(3))(4)] and [K(18c6)][U(N(SiMe3)(2))(4)], both presenting the U-III ion in similar pseudotetrahedral coordination environments but with different O- or N-donor ...

Amer Chemical Soc2014

O-17 NMR and Density Functional Theory Study of the Dynamics of the Carboxylate Groups in DOTA Complexes of Lanthanides in Aqueous Solution

Lothar Helm

The rotation of the carboxylate groups in DOTA (DOTA = 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetate) complexes of several lanthanide ions and Sc3+ was investigated with density functional theory (DFT) calculations and with variable temperature O-17 ...

2012

Improving Sensitivity in Solid State NMR : Surfaces, Quadrupolar Nuclei and Dynamic Nuclear Polarization

Sensitivity in Nuclear Magnetic Resonance (NMR), especially in solid-state NMR, has always been a challenging and important issue and thus a motivation for new developments. The magnetic field B0, the gyromagnetic ratios of the observed nuclei, as well as ...

EPFL2012

Facile synthesis and relaxation properties of novel bispolyazamacrocyclic Gd3+ complexes: An attempt towards calcium-sensitive MRI contrast agents

Eva Jakab Toth, Anurag Mishra

Three novel GdDO3A-type bismacrocyclic complexes, conjugated to Ca2+ chelating moieties like ethylenediamine-tetraacetic acid and diethylenetriamine pentaacetic acid bisamides, were synthesized as potential "smart" magnetic resonance imaging contrast agent ...

2008