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Concept

Diradical

Publications associées (23)

Large Orbital Moment of Two Coupled Spin-Half Co Ions in a Complex on Gold

Stefano Rusponi, Chao Li, Boris Sorokin

The magnetic propertiesof transition-metal ions aregenerallydescribed by the atomic spins of the ions and their exchange coupling.The orbital moment, usually largely quenched due the ligand field,is then seen as a perturbation. In such a scheme, S = 1/2 io ...

AMER CHEMICAL SOC2023

Single molecule fluorescence and phosphorescence studies using a scanning tunneling microscope

Abhishek Grewal

This thesis investigates novel single-molecule luminescence phenomena at their inherent, sub-molecular length scale. The microscopic understanding of luminescence processes will be crucial for the continued improvement of organic optoelectronic and semicon ...

EPFL2022

Photoinduced disinfection in sunlit natural waters: Measurement of the second order inactivation rate constants between E-coli and photogenerated transient species

César Pulgarin, Stefanos Giannakis

This work uncovers the implications of the estimation of exogenous inactivation rates for E. coli after the initial lag phase, and presents a strategy for the determination of the second-order inactivation rate constants (k2nd) of these bacteria with relev ...

PERGAMON-ELSEVIER SCIENCE LTD2018

Conservation of vibrational coherence in ultrafast electronic relaxation: The case of diplatinum complexes in solution

Majed Chergui, Gerald Auböck, Dominik Kinschel, Roberto Monni

We report the results of ultrafast transient absorption studies of tetrakis(l-pyrophosphito) diplatinate(II), Pt-2(mu-P(2)O(5)H2)(4) (Pt(pop)) and its perfluoroborated derivative Pt-2(mu-P2O5(BF2)(4) (Pt(pop-BF2)) in water and acetonitrile upon e ...

Elsevier2017

Origin of the Spin-Orbital Liquid State in a Nearly J=0 Iridate Ba3ZnIr2O9

Henrik Moodysson Rønnow, Martin Mansson, Paul Gregory Freeman

We show using detailed magnetic and thermodynamic studies and theoretical calculations that the ground state of Ba3ZnIr2O9 is a realization of a novel spin-orbital liquid state. Our results reveal that Ba3ZnIr2O9 with Ir5+ (5d(4)) ions and strong spin-orbi ...

2016

Lifetimes of long-lived states in inhomogeneous magnetic fields

Geoffrey Bodenhausen, Srinivas Chinthalapalli

Long-lived states (LLS), also known as singlet states, have been widely studied in the last decade. So far, LLS have only been observed in homogeneous magnetic fields, which preclude applications to many biological samples that are inherently inhomogeneous ...

Elsevier2015

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

Geoffrey Bodenhausen, Sami Jannin, Aurélien Bornet, Jonas Milani, Diego Carnevale, Daniele Mammoli, Nicola Salvi, 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

Fragmentation mechanism of UV-excited peptides in the gas phase

Thomas Rizzo, Oleg Boyarkine, Michael Zachary Kamrath, Aleksandra Zabuga

We present evidence that following near-UV excitation, protonated tyrosine- or phenylalanine–containing peptides undergo intersystem crossing to produce a triplet species. This pathway competes with direct dissociation from the excited electronic state and ...

American Institute of Physics2014

A Vibronic Coupling Hamiltonian to Describe the Ultrafast Excited State Dynamics of a Cu(I)-Phenanthroline Complex

Ursula Röthlisberger, Ivano Tavernelli, Thomas James Penfold, Gloria Capano

We present a model Hamiltonian to study the nonadiabatic dynamics of photoexcited Cu(dmp)(2), (dmp = 2,9-dimethyl-1,10-phenanthroline). The relevant normal modes, identified by the magnitude of the first order coupling constants, correspond closely to ...

2014

Photobleaching Kinetics and Time-Integrated Emission of Fluorescent Probes in Cellular Membranes

Daniel Sage

Since the pioneering work of Hirschfeld, it is known that time-integrated emission (TiEm) of a fluorophore is independent of fluorescence quantum yield and illumination intensity. Practical implementation of this important result for determining exact prob ...

Mdpi Ag2014

Dynamics of UV-excited, protonated peptides in the gas phase

Aleksandra Zabuga

The scope of this thesis is the electronically excited state dynamics of protonated peptides and their photofragmentation mechanism. UV radiation induces fragmentation of biological molecules and might cause various diseases, such as cataracts or skin canc ...

EPFL2014

High proton spin polarization with DNP using the triplet state of pentacene-d14

Tim Rolf Eichhorn

The proton spins in a large naphthalene single crystal have been very efficiently polarized using optically excited triplet states of fully deuterated pentacene (C22D14) guest molecules. In a field of 0.3 T a proton polarization of 0.50 has been achieved. ...

Elsevier2013

Quantum dynamics study of the competing ultrafast intersystem crossing and internal conversion in the "channel 3" region of benzene

Thomas James Penfold

Time-resolved photoelectron spectroscopy can obtain detailed information about the dynamics of a chemical process on the femtosecond timescale. The resulting signal from such detailed experiments is often difficult to analyze and therefore theoretical calc ...

American Institute of Physics2012

The Cause for Tremendous Acceleration of Chloride Substitution via Base Catalysis in the Chloro Pentaammine Cobalt(III) Ion

François Rotzinger, Basile Curchod

The base hydrolysis reaction of Co(NH3)5Cl2+ was investigated using density functional theory and molecular orbital methods. Geometries and energies of conjugate bases, intermediates, transition states, and minimum energy crossing points were computed. For ...

2011

Singlet-Triplet Excitations and High-Field Magnetization in CuTe2O5

Helmuth Berger, Zhe Wang

By measuring the THz electron spin resonance (ESR) transmission spectra and high-field magnetization on the spin-gapped system CuTe2O5, we identified the singlet-triplet excitations in the dimerized non-magnetic ground state. The determined spin-gap value ...

2011

Study of the pO2-sensitivity of the dendrimeric and free forms of Pd-meso-tetra(4-carboxyphenyl)porphyrin, incorporated or not in chitosan-based nanoparticles

Hubert van den Bergh, Georges Wagnières, Patrycja Nowak-Sliwinska

The concentration of oxygen and its rate of consumption are important factors in certain medical treatments, such as radiotherapy and photodynamic therapy (PDT). Measuring the tissue concentration of oxygen or its partial pressure (pO2) can be achieved by ...

Schweizerische Chemische Gesellschaft2011

Vibrational coherences and relaxation in the high-spin state of aqueous [Fell(bpy)3]2+

Majed Chergui, Frank van Mourik, Andrea Cannizzo, Amal El Nahhas, Cristina Consani

Dizzy cooling: Femtosecond excitation of the singlet states of aqueous [FeII(bpy)3]2+ (bpy=2,2-bipyridine) leads to the formation of a vibrationally hot quintet state that exhibits wave-packet dynamics arising from a chelate-ring and bending mode. The vibr ...

Wiley-VCH Verlag GmbH2009

Lanthanide Luminescent Bioprobes (LLBs)

Jean-Claude Bünzli

Lanthanide luminescent bioprobes (LLBs) are amongst the most sensitive luminescent probes because their excited states are long-lived, which allows time-resolved detection (TRD) of their luminescence, boosting the signal-to-noise ratio and the sensitivity; ...

2009

Structural Determination of a Short-Lived Excited Iron(II) Complex by Picosecond X-Ray Absorption Spectroscopy

Majed Chergui, Wojciech Gawelda, Van Thai Pham

Structural changes of the Fe(II)-tris-bipyridine ([FeII(bpy)3]2+) complex induced by ultrashort pulse excitation and population of its short-lived (?0.6 ns) quintet high spin state were detected by picosecond x-ray absorption spectroscopy. The structural r ...

2007

A Novel Strategy for the Design of 8-Hydroxyquinolinate- Based Lanthanide Bioprobes That Emit in the Near Infrared Range

Jean-Claude Bünzli, Caroline Vandevyver, Steve Comby

A new polydentate tripodal ligand T2soxMe was synthesized to take advantage of the chelating effect of tridentate 8- hydroxyquinolinate subunits. Potentiometric and spectrophotometric titrations reveal seven pKa values of between 3.7 and 10.2. In water, th ...

2007