Mediaspace scheduled maintenance: Aug 25, 2026 07:00 - 12:00 AM. During this time, videos will be temporarily unavailable. Check status updates.

Concept

Mendélévium

Publications associées (26)

A customized MOF-polymer composite for rapid gold extraction from water matrices

Wendy Lee Queen, Daniel Teav Sun, Shuliang Yang, Jun Li, Li Peng, Olga Syzgantseva

With the fast-growing accumulation of electronic waste and rising demand for rare metals, it is compelling to develop technologies that can promotionally recover targeted metals, like gold, from waste, a process referred to as urban mining. Thus, there is ...

AMER ASSOC ADVANCEMENT SCIENCE2023

Stabilizing Unusual Oxidation States of Lanthanides in Molecular Complexes: Synthesis, Properties, and Reactivity

Aurélien René Willauer

The chemistry of divalent lanthanides has generated increasing interest in the past years due to their redox properties and unique reaction pathways. Notably, molecular complexes of low-valent lanthanides have been shown to be suitable one-electron reducta ...

EPFL2022

Structure and small molecule activation reactivity of a metallasilsesquioxane of divalent ytterbium

Rosario Scopelliti, Marinella Mazzanti, Aurélien René Willauer, Anna Maria Dabrowska

The first metallasilsesquioxane of a divalent lanthanide, Yb{Cy7Si7O11(OSiMe3)}(THF),1, was synthesized and structurally characterized. The Cy7Si7O11(OSiMe3)(2-)ligands in1bind two Yb(ii) ions in a bridging mode. The dinuclear complex effects the two- ...

Royal Society of Chemistry2020

4 f occupancy and magnetism of rare-earth atoms adsorbed on metal substrates

Harald Brune, Stefano Rusponi, Sebastian Stepanow, Jan Gui-Hyon Dreiser, Pietro Gambardella, Fabio Donati, Christian Wäckerlin, Aparajita Singha, Romana Baltic

We report x-ray absorption spectroscopy and x-ray magnetic circular dichroism measurements as well as multiplet calculations for Dy, Ho, Er, and Tm atoms adsorbed on Pt(111), Cu(111), Ag(100), and Ag(111). In the gas phase, all four elements are divalent a ...

Amer Physical Soc2017

Magnetic properties of surface-adsorbed single rare earth atoms, molecules, and atomic scale clusters

Aparajita Singha

This thesis presents combined experimental and theoretical investigations of nanoscale, surface-supported magnets based on rare earths (RE) to understand and control the magnetic properties down to the scale of single atoms. We present the effects of adato ...

EPFL2017

Complexation of [Gd(DTTA–Me)(H2O)2]− by Fluoride and Its Consequences to Water Exchange

Lothar Helm, Loïck Moriggi, Shima Karimi

The displacement of water molecule(s) from the inner coordination sphere of [Gd(DTTA–Me)(H2O)2]− (DTTA = ethylenetriamine-N,N,N″,N″-tetraacetate) by fluoride has been studied by multinuclear NMR relaxation (1H, 17O, 19F) and DFT calculations. Fluoride anio ...

American Chemical Society2016

Synthesis of molecular complexes for small molecule activation

Julie Renée Michelle Andrez

The redox chemistry of f-elements is drawing the attention of inorganic chemists due to their unusual reaction pathways. Notably low-valent f-element complexes have been shown to be able to activate small molecules such as CO2 and N2 in mild conditions. Co ...

EPFL2016

Synthesis and spectroscopy of anionic tridentate benzimidazole-pyridine carboxylate and tetrazolate chromophore ligands

Svetlana Eliseeva

We report on seven new anionic benzimidazole-pyridine carboxylate and tetrazolate tridentate (NNO)-N-boolean AND-O-boolean AND and (NNN)-N-boolean AND-N-boolean AND ligands that are modified with chromophore (phenyl, biphenyl, naphthyl) and solubilizing gr ...

Elsevier2015

Solvent Exchange and Electron-Spin Relaxation on Homoleptic Acetonitrile Complexes of Trivalent Lanthanides

Lothar Helm

Homoleptic acetonitrile complexes [Nd(CH3CN)(9)]Al(OC(CF3)(3))(4), [Dy(CH3CN)(9)]Al(OC(CF3)(3))(4), and [Tm(CH3CN)(8)]Al(OC(CF3)(3))(4) have been studied in anhydrous acetonitrile by 14N and 1H NMR relaxation. Solvent-exchange rate constants ...

American Chemical Society2015

Mossbauer studies of the peculiar magnetism in parent compounds of the iron-based superconductors

A review of the magnetism in the parent compounds of the iron-based superconductors is given based on the transmission Mossbauer spectroscopy of Fe-57 and Eu-151. It was found that the 3d magnetism is of the itinerant character with varying admixture of th ...

Taylor & Francis Ltd2015

Tridentate Benzimidazole-Pyridine-Tetrazolates as Sensitizers of Europium Luminescence

Rosario Scopelliti, Jean-Claude Bünzli, Svetlana Eliseeva

We report on new anionic tridentate benzimidazole-pyridine-tetrazolate ligands that form neutral 3:1 complexes with trivalent lanthanides. The ligands are UV-absorbing chromophores that sensitize the red luminescence of europium with energy-transfer effici ...

Amer Chemical Soc2014

Free volume in ionic liquids: a connection of experimentally accessible observables from PALS and PVT experiments with the molecular structure from XRD data

Safak Bulut

In the current work, free volume concepts, primarily applied to glass formers in the literature, were transferred to ionic liquids (ILs). A series of 1-butyl-3-methylimidazolium (C4MIM) based ILs was investigated by Positron Annihilation Lifetime Spec ...

Royal Soc Chemistry2013

Stereoselectivity and electrostatics in charge-transfer Mn- and Cs-TCNQ(4) networks on Ag(100)

Klaus Kern, Sebastian Stepanow

Controlling supramolecular self-assembly is a fundamental step towards molecular nanofabrication, which involves a formidable reverse engineering problem. It is known that a variety of structures are efficiently obtained by assembling appropriate organic m ...

Nature Publishing Group2012

Ga3+ and Y3+ Cationic Substitution in Mesoporous TiO2 Photoanodes for Photovoltaic Applications

Michael Graetzel, Aravind Kumar Chandiran, Lioz Etgar

The optoelectronic properties of transparent nanocrystalline TiO2 films were modified by the incorporation of a low level of Ga3+ or Y3+ cations. After optimizing their relative concentration level, we were able to increase in a noticeable manner the power ...

American Chemical Society2011

Benzothiazole- and Benzoxazole-Substituted Pyridine-2-Carboxylates as Efficient Sensitizers of Europium Luminescence

Rosario Scopelliti, Jean-Claude Bünzli, Frédéric Gumy

A facile synthesis of benzothiazole- and benzoxazole-substituted pyridine-2-carboxylic acids has been developed. These ligands form mononuclear nine-coordinate complexes [Ln(κ3-ligand)2(κ1-ligand)(H2O)2] with light and heavy trivalent lanthanides, as estab ...

2009

Structural, Spectroscopic, and Thermodynamic Consequences of Anti-Chelate Effect in Nine-Coordinate Lanthanide Podates

Jean-Claude Bünzli, Frédéric Gumy

The connection of three tridentate 2,6-bis(1-ethyl-benzimidazol-2-yl)pyridine binding units to an extended sulfurcontaining tripodal anchor in the ligand L9 yields nine-coordinate podates [Ln(L9)]3+ upon reaction with trivalent lanthanides, Ln(III). Struct ...

2009

Exploring the potential of europium(III) luminescence for the detection of phase transitions in ionic liquid crystals

Jean-Claude Bünzli, Anne-Sophie Chauvin, Frédéric Gumy

The ionic liquid crystal [C12-mim]Cl has been doped with 5 mol% europium nitrate and the photophysical properties of both the ionic liquid and the trivalent europium ion have been monitored with respect to temperature in the range of 248 to +120 uC. The re ...

Royal Society of Chemistry2007

Selective Self-Assembly of Hexameric Homo- and Heteropolymetallic Lanthanide Wheels: Synthesis, Structure, and Photophysical Studies

Jean-Claude Bünzli, Marinella Mazzanti

A rational approach to the formation of pure heteropolymetallic lanthanide complexes that uses a two-step assembly strategy and exploits the different size requirements of the two metals included in the final structure is described. The investigation of th ...

2007

Mécanismes d'isomérisation et d'échange de ligand de complexes octaédriques labiles de cobalt (II) : étude par RMN et haute pression

Fabrice Riblet

There are only few structural thermodynamic and kinetic studies on labile octahedral complexes available today. Octahedral paramagnetic compounds of cobalt(II) have an optimum electronic relaxation leading to NMR spectra with good resolution. Therefore, th ...

EPFL2007

Benefiting from the Unique Properties of Lanthanide Ions

Jean-Claude Bünzli

The recent upsurge of interest in contrast agents for magnetic resonance imaging, of luminescent chemosensors for medical diagnostic, and lately, for optical imaging of cells has generated an impressive momentum for the coordination and supramolecular chem ...

American Chemical Society2006