Publications associées à Encapsulation of labile trivalent lanthanides into a homobimetallic chromium(III)-containing triple-stranded helicate. Synthesis, characterization, and divergent intramolecular energy transfers

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

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

Carbon dioxide reduction by lanthanide(iii) complexes supported by redox-active Schiff base ligands

Rosario Scopelliti, Marinella Mazzanti, Davide Toniolo, Nadir Jori

Here we have explored the ability of Schiff bases to act as electron reservoirs and to enable the multi-electron reduction of small molecules by lanthanide complexes. We report the reductive chemistry of the Ln(iii) complexes of the tripodal heptadentate S ...

2020

Colorimetry of Luminescent Lanthanide Complexes

Anne-Sophie Chauvin, Julien Alexandre Andres

Europium, terbium, dysprosium, and samarium are the main trivalent lanthanide ions emitting in the visible spectrum. In this work, the potential of these ions for colorimetric applications and colour reproduction was studied. The conversion of spectral dat ...

2020

Tuning the structure, reactivity and magnetic communication of nitride-bridged uranium complexes with the ancillary ligands

Rosario Scopelliti, Marinella Mazzanti, Anne-Clémence Corminboeuf, Ivica Zivkovic, Alberto Fabrizio, Luciano Barluzzi

Molecular uranium nitride complexes were prepared to relate their small molecule reactivity to the nature of the U & xe001;N & xe001;U bonding imposed by the supporting ligand. The U4+-U4+ nitride complexes, [NBu4][{(((BuO)-Bu-t)(3)SiO)(3)U}(2)(mu-N)], [NB ...

2019

Water exchange studies of lanthanide complexes and aqua ions

Shima Karimi

Complexes of lanthanide (III) ions have been used in structural studies of biomolecules and as contrast agents (CA). Clinically approved CAs have only one water molecule in their first coordination sphere. Structure and water exchange rate of these complex ...

EPFL2016

Water Exchange on [Ln(DO3A)(H2O)2] and [Ln(DTTA–Me)(H2O)2]− Studied by Variable Temperature, Pressure, and Magnetic Field NMR

Lothar Helm, Shima Karimi

Water exchange kinetics of [Ln(L)(H2O)2]x complexes (Ln = Pr, Nd, Dy, Tm, and Yb; L = DO3A and DTTA–Me) were studied by 17O NMR spectroscopy as a function of temperature, pressure, and frequency and by 1H nuclear magnetic relaxation dispersion. Water excha ...

American Chemical Society2016

Lanthanide(II) Complexes Supported by N,O-Donor Tripodal Ligands: Synthesis, Structure, and Ligand-Dependent Redox Behavior

Rosario Scopelliti, Marinella Mazzanti, Julie Renée Michelle Andrez

The preparation and characterization of a series of complexes of the Yb and Eu cations in the oxidation state II and III with the tetradentate N,O-donor tripodal ligands (tris(2-pyridylmethyl)amine (TPA), BPA(-) (HBPA=bis(2-pyridylmethyl)(2-hydroxybenzyl)a ...

2015

Tridentate Benzimidazole-Pyridine-Tetrazolates as Sensitizers of Europium Luminescence

Jean-Claude Bünzli, Rosario Scopelliti, 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

A Eu(III) Tetrakis(b-diketonate) Dimeric Complex: Photophysical Properties, Structural Elucidation by Sparkle/AM1 Calculations, and Doping into PMMA Films and Nanowires

Jean-Claude Bünzli, Rosario Scopelliti

Reaction of Ln(III) with a tetrakis(diketone) ligand H4L [1,1?-(4,4?-(2,2-bis((4-(4,4,4-trifluoro-3-oxobutanoyl) phenoxy)methyl)propane-1,3-diyl)bis(oxy)bis(4,1-phenylene))bis(4,4,4-trifluorobutane-1,3-dione)] gives new podates which, according to mass spe ...

American Chemical Society2014

Energy transfer in coumarin-sensitised lanthanide luminescence: investigation of the nature of the sensitiser and its distance to the lanthanide ion

Anne-Sophie Chauvin, Julien Alexandre Andres

A series of lanthanide complexes Ln(dpxCy)(3) have been synthesised. The ligands are composed of a coordinating dipicolinic acid backbone decorated with a polyoxyethylene arm fitted with a coumarin moiety at its extremity. The nature of the coumarin ...

Royal Society of Chemistry2013

Biphenylene-bridged mesostructured organosilica as a novel hybrid host material for Ln(III) (Ln = Eu, Gd, Tb, Er, Yb) ions in the presence of 2-thenoyltrifluoroacetone

Jean-Claude Bünzli

A hierarchically ordered 4,4'-biphenylene-bridged mesoporous organosilica framework (Bp-PMO) has been synthesized with the aim of using it as a new hybrid host for Ln(III) ions. A series of novel organic-inorganic luminescent hybrid materials have been obt ...

Royal Society of Chemistry2013

Lanthanide Complexes Formed with the Tri- and Tetraacetate Derivatives of Bis(aminomethyl)phosphinic Acid: Equilibrium, Kinetic and NMR Spectroscopic Studies

Laurent Quebatte, André Merbach, Eva Jakab Toth

The lanthanide(III) complexes formed with the tri- and tetraacetate derivatives of bis(aminomethyl)phosphinic acid, L1 and L2, respectively, have been studied by pH potentiometry, spectrophotometry and 1H and 17O NMR spectroscopy. L1 forms [Ln(L1)], [Ln(L1 ...

Wiley-Blackwell2012

Isoquinoline-Based Lanthanide Complexes: Bright NIR Optical Probes and Efficient MRI Agents

Sandrine Villette, Lothar Helm, Eva Jakab Toth

In the objective of developing ligands that simultaneously satisfy the requirements for MRI contrast agents and near-IR emitting optical probes that are suitable for imaging, three isoquinoline-based polyaminocarboxylate ligands, L1, L2 and L3, have been s ...

2012

New Bisaqua Picolinate-Based Gadolinium Complexes as MRI Contrast Agents with Substantial High-Field Relaxivities

Lothar Helm, Marinella Mazzanti

Two new tripodal heptadentate ligands, H4dpaba (N,N'-bis[(6-carboxypyridin-2-yl)methyl]aspartic acid) and H3mpatcn(1,4-bis(methoxycarbonyl)-7-[(6-carboxypyridin-2-yl)methyl]-1,4,7-triazacyclononane), which bear one or two picolinate pendant arms, have been ...

Wiley-Blackwell2012

Uranyl complexes formed with a para-t-butylcalix[4]arene bearing phosphinoyl pendant arms on the lower rim. Solid and solution studies

Jean-Claude Bünzli

The current interest in functionalized calixarenes with phosphorylated pendant arms resides in their coordination ability towards f elements and capability towards actinide/rare earth separation. Uranyl cation forms 1: 1 and 1: 2 (M : L) complexes with a t ...

2012

6-Phosphoryl Picolinic Acids as Europium and Terbium Sensitizers

Anne-Sophie Chauvin, Julien Alexandre Andres

Three 6-phosphoryl picolinic acid (6PPA) derivatives were synthesized and used as europium and terbium sensitizers. Two of the three ligands (6-diethoxyphosphoryl picolinic acid (Hdeppa) and 6-monoethoxyphosphoryl picofinic acid (H(2)meppa)) are water-solu ...

2011

Dimerization of Dendrimeric Lanthanide Complexes: Thermodynamic, Thermal, and Liquid-Crystalline Properties

Thomas Binderup Jensen, Kurt Schenk

A series of 10 different mesomorphic semidendrimeric tridentate ligands L5-L14 grafted with terminal cyanobiphenyl groups have been synthesized. Upon reaction with Ln(NO3)(3) (Ln = trivalent lanthanide), the central 2,6-bis(N-ethylbenzimidazol-2-yl)pyridin ...

2010

Europium Complexes of Tris(dipicolinato) Derivatives Coupled to Methylumbelliferone: A Double Sensitization

Anne-Sophie Chauvin, Julien Alexandre Andres

A para-poly(oxyethylene) dipicolinic acid derivative coupled to methylumbelliferone was synthesized and used as a ligand for coordination with europium ions. Characterization of the complex by mass spectrometry and spectrophotometry was performed in aqueou ...

Wiley-Blackwell2010

Synthesis and Photophysical Properties of Ln(III)-DOTA-Bipy Complexes and Ln(III)-DOTA-Bipy-Ru-II Coordination Conjugates

Jean-Claude Bünzli, Svetlana Eliseeva

The synthesis and the systematic and comparative photo-physical study of a series of visible (Eu-III, Tb-III) and NIR-emitting (Nd-III, Yb-III) lanthanide complexes (Ln(2)L) and ruthenium lanthanide coordination conjugates (Ln(2)LRu) are reported. The Gd-I ...

Wiley-Blackwell2010

2,2’-Bipyrimidine as Efficient Sensitizer of the Solid-State Luminescence of Lanthanide and Uranyl Ions from Visible to Near-Infrared

Jean-Claude Bünzli, Frédéric Gumy

Treatment of Ln(NO3)3.nH2O with 1 or 2 equiv 2,2-bipyrimidine (BPM) in dry THF readily afforded the monometallic complexes [Ln(NO3)3(bpm)2] (Ln=Eu, Gd, Dy, Tm) or [Ln(NO3)3(bpm)2]THF (Ln=Eu, Tb, Er, Yb) after recrystallization from MeOH or THF, respectivel ...

2009