A5038379542- Electron Spin Resonance Studies
- Advanced NMR Techniques and Applications
- Lanthanide and Transition Metal Complexes
- Magnetism in coordination complexes
- Solid-state spectroscopy and crystallography
- Crystallization and Solubility Studies
- X-ray Diffraction in Crystallography
- RNA Research and Splicing
- RNA and protein synthesis mechanisms
- Photochemistry and Electron Transfer Studies
- RNA modifications and cancer
- Atomic and Subatomic Physics Research
- Advanced Chemical Physics Studies
- Catalytic Processes in Materials Science
- Electrochemical Analysis and Applications
- Muon and positron interactions and applications
- nanoparticles nucleation surface interactions
- Liver Disease Diagnosis and Treatment
- Layered Double Hydroxides Synthesis and Applications
- Bacteriophages and microbial interactions
- Advanced MRI Techniques and Applications
- Copper-based nanomaterials and applications
- Fibroblast Growth Factor Research
- Nuclear Physics and Applications
- Metal-Organic Frameworks: Synthesis and Applications
ETH Zurich
2016-2025
Charles Humbert 8
2018-2020
Board of the Swiss Federal Institutes of Technology
2020
Laboratoire de Chimie
2015
Institute of Inorganic Chemistry of the Slovak Academy of Sciences
2015
Fritz Haber Institute of the Max Planck Society
2006-2010
Institute of Physics
2010
Chinese Academy of Sciences
2010
University of Konstanz
2008
Boreskov Institute of Catalysis
2000-2007
A series of seven functionalized nitroxide biradicals (the bTbK biradical and six derivatives) are investigated as exogenous polarization sources for dynamic nuclear (DNP) solid-state NMR at 9.4 T with ca. 100 K sample temperatures. The impact electron relaxation times on the DNP enhancement (ε) is examined, we observe that longer inversion recovery phase memory provide larger ε. All radicals tested in both bulk 1,1,2,2-tetrachloroethane solutions mesoporous materials, difference ε between...
A series of 37 dinitroxide biradicals have been prepared and their performance studied as polarizing agents in cross-effect DNP NMR experiments at 9.4 T 100 K 1,1,2,2-tetrachloroethane (TCE).
Dynamic nuclear polarization (DNP) solid-state magnetic resonance (NMR) has developed into an invaluable tool for the investigation of a wide range materials. However, sensitivity gain achieved with many polarizing agents suffers from unfavorable field and magic angle spinning (MAS) frequency dependence. We present series new hybrid biradicals, soluble in organic solvents, that consist isotropic narrow electron paramagnetic line radical, α,γ-bisdiphenylene-β-phenylallyl (BDPA), tethered to...
TinyPol binitroxides provide significantly higher DNP enhancement factors for solid-state NMR spectroscopy at high magnetic fields than today's reference radical AMPUPol.
We evaluate the overall sensitivity gains provided by a series of eighteen nitroxide biradicals for dynamic nuclear polarization (DNP) solid-state NMR at 9.4 T and 100 K, including eight new biradicals. find that in best performing group factors contributing to gains, namely DNP enhancement, build-up time, contribution factor, often compete with each other leading very similar across range NaphPol HydroPol are found provide factors, organic aqueous solvents respectively. One biradicals,...
Pricking the surface: STM and EPR spectroscopy demonstrate presence of color centers on thin MgO(001) films their interaction with Au atoms. These systems are used to calibrate IR stretching frequencies CO bound clusters. Clusters regular terrace sites remain neutral while nucleation at results in a charge transfer from surface cluster.
In the present Letter first electron paramagnetic resonance spectra of single metal atoms on a crystalline oxide surface are presented. For Au MgO(001) film investigated here an analysis angular dependent positions and hyperfine coupling to $^{17}\mathrm{O}$ shows that bound top oxygen ions terrace film. This result is in perfect agreement with scanning tunneling microscopy measurements at 5 K presented here. The measured matrix components allow experimental verification theoretically...
The CO binding behavior to gold particles supported on MgO thin films has been analyzed with scanning tunneling microscopy (STM) and infrared spectroscopy (IRAS). ad-particles accommodate excess electrons that originate either from a charge transfer through the oxide film or local interaction electron-rich defects act as Au nucleation centers. enhanced electron density in aggregates affects both spatial distribution vibrational properties of adsorbed species. Whereas preferential attachment...
Double electron−electron resonance has attracted growing attention as a technique to study structure and conformational changes of biomacromolecules. Here, new combination paramagnetic labels is experimentally tested, one being commonly used nitroxide radical, the other Gd3+ ion. The Gd3+−nitroxide spin pair can serve good substitute for nitroxide−nitroxide potentially provides link experimental approaches dealing with structural information.
{Cu(bpy)(H(2)O)(2)(BF(4))(2)(bpy)} (Cu-MOF; MOF=metal-organic framework; bpy=4,4'-bipyridine), with a 3D-interpenetrated structure and saturated Cu coordination sites in the framework, possesses unexpectedly high activity ring-opening reaction of epoxides MeOH, although rate drops remarkably more bulky alcohols. This (apparent) size selection single Cu(2+) an identical environment crystalline matrix resemble zeolites. The real nature active was investigated by attenuated total reflection...
We present the first example of chemoselective site-specific spin labeling a monomeric protein with two spectroscopically orthogonal labels: gadolinium(III) chelate complex and nitroxide radical. A detailed analysis performance commercially available Gd(III) ligands in Gd(III)-nitroxide pulse double electron-electron resonance (DEER or PELDOR) experiment is reported. modification flip angle pump DEER proposed to optimize sensitivity.
Nanosized gold particles were functionalised with two types of paramagnetic surface tags, one having a nitroxide radical and the other carrying DTPA complex loaded Gd3+. Selective measurements nitroxide–nitroxide, Gd3+–nitroxide Gd3+–Gd3+ distances performed on this system information distance distribution in three spin pairs was obtained. A numerical analysis dipolar frequency distributions is presented for Gd3+ centres moderate magnitudes zero-field splitting, range detection frequencies...
The relaxation induced dipolar modulation enhancement (RIDME) technique is applied at W-band microwave frequencies around 94 GHz to a pair of Gd(III) complexes that are connected by rodlike spacer, and the extraction interspin distance distribution discussed. A pattern derived from RIDME experimental data superposition Pake-like patterns corresponding fundamental interaction higher harmonics thereof. Intriguingly, relative weights stretched do not depend significantly on mixing time. As much...
Article15 February 2018Open Access Transparent process Structural basis of siRNA recognition by TRBP double-stranded RNA binding domains Gregoire Masliah Institute Molecular Biology and Biophysics, ETH Zürich, Switzerland Search for more papers this author Christophe Maris Sebastian LB König Department Biochemistry, University Maxim Yulikov Laboratory Physical Chemistry, Florian Aeschimann Novartis Institutes Biomedical Research, Basel, Anna L Malinowska Pharmaceutical Sciences, Chemistry...
The development of magic-angle spinning dynamic nuclear polarization (MAS DNP) has allowed atomic-level characterization materials for which conventional solid-state NMR is impractical due to the lack sensitivity. rapid progress MAS DNP been largely enabled through understanding rational design concepts more efficient polarizing agents (PAs). Here, we identify a new principle so far overlooked. We find that local geometry around unpaired electron can change enhancement by an order magnitude...
Abstract Interaction of heterogeneous nuclear ribonucleoprotein A1 (hnRNP A1) with specific single‐stranded RNA and its relation to liquid‐liquid phase separation (LLPS) were studied in vitro by magnetic resonance based on site‐directed spin labelling. An ensemble model dispersed hnRNP the absence was derived from distance distributions between labelled sites small angle X‐ray scattering. This revealed a compact state low‐complexity domain interaction recognition motifs. Paramagnetic...
This is a methodological guide to the use of deep neural networks in processing pulsed dipolar spectroscopy (PDS) data encountered structural biology, organic photovoltaics, photosynthesis research, and other domains featuring long-lived radical pairs paramagnetic metal ions. PDS uses distance dependence magnetic interactions; measuring single well-defined straightforward, but extracting distributions hard mathematically ill-posed problem requiring careful regularisation background fitting....
The sensitivity of NMR spectroscopy is considerably enhanced by dynamic nuclear polarization (DNP). In DNP transferred from unpaired electrons a polarizing agent to nearby proton spins. solids, this transfer followed the transport hyperpolarization bulk via 1 H-1 H spin diffusion. efficiency these steps critical obtain high gains, but pathways for in region near electron spins are unclear. Here we report series seven deuterated and one fluorinated TEKPol biradicals probe effect deprotonation...
Innocence lost: The IR spectra of Au/CO complexes adsorbed on a MgO(001) film differ from the corresponding neutral Au clusters. Calculations indicate this shift 200–250 cm−1 can be associated with negative charge complex. For so-called color centers transfer is expected, however atoms terrace sites are neutral. Thus, CO in fact induces instead reporting state atoms.
Multi-spinning: The use of modified triphosphates and DNA polymerases has resulted in the multiple spin-labeling (see picture). A helix entirely labeled with paramagnetic centers been generated this way investigated by EPR spectroscopy.
The conversion of layered metal hydroxides into a metal–organic framework is studied for the case Fe–BTC (BTC = 1,3,5-benzenetricarboxylate). synthesis occurs at room temperature as early 5 min using double hydroxide, green rust, precursor and yielding product with high surface area. Monitoring crystallisation kinetics function degree crystallinity iron hydroxide reveals dependence MOF assembly on presence structure in precursor. Further insights evolution Fe centers are provided by...