Publications associées à Broadband femtosecond fluorescence spectroscopy of [Ru(bpy)3]2+

Symmetry-Induced Singlet-Triplet Inversions in Non-Alternant Hydrocarbons

Anne-Clémence Corminboeuf, Jacob Terence Blaskovits, Marc Hamilton Folkmann Garner

Molecules with inversion of the singlet and triplet excited-state energies are highly promising for the development of organic light-emitting diodes (OLEDs). To date, azaphenalenes are the only class of molecules where these inversions have been identified ...

Wiley-VCH Verlag GmbH2023

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

Photochemical oxidation of phenols and anilines mediated by phenoxyl radicals in aqueous solution

Silvio Canonica, Urs von Gunten, Stephanie Christa Remke

Reactive intermediates formed upon irradiation of chromophoric dissolved organic matter (CDOM) contribute to the degradation of various organic contaminants in surface waters. Besides well-studied "short-lived" photo oxidants, such as triplet state CDOM (3 ...

PERGAMON-ELSEVIER SCIENCE LTD2022

Superexchange mechanism and quantum many body excitations in the archetypal di-Cu oxo-bridge

Cédric Weber, Edward Baxter Linscott

The hemocyanin protein binds and transports molecular oxygen via two copper atoms at its core. The singlet state of the Cu2O2 core is thought to be stabilised by a superexchange pathway, but detailed in situ computational analysis is complicated by the mul ...

NATURE PUBLISHING GROUP2020

A general framework for non-exponential delayed fluorescence and phosphorescence decay analysis, illustrated on Protoporphyrin IX

Georges Wagnières, Aurelien Stephen Arnaud Gregor, Emmanuel Louis Arthur Gerelli, Jaroslava Joniová

Delayed fluorescence (DF) is a long-lived luminescence process used in a variety of applications ranging from oxygen sensing in biological tissues to organic Light Emitting Diodes. In common cases, DF results from the deexcitation of the first excited trip ...

2020

A systematic investigation on the bactericidal transient species generated by photo-sensitization of natural organic matter (NOM) during solar and photo Fenton disinfection of surface waters

César Pulgarin, Stefanos Giannakis, Mona Kohantorabi, Ling Feng

In this work, the role of dissolved oxygen in the solar and the photo-Fenton-mediated E. coli inactivation process was put under scrutiny. The effect of transient species that were produced in the presence of various natural organic matter isolates (NOM), ...

ELSEVIER SCIENCE BV2019

Non-equilibrium dynamics of di-platinum complexes and molecular dyes in solution: Insights from transient absorption and two-dimensional Fourier transform spectroscopy

Lars-Hendrik Mewes

Unraveling the interplay between electronic- and vibrational degrees of freedom on the earliest time scales of physical, chemical and biological processes is crucial to gaining insight into the mechanisms that govern the world around us, since it is during ...

EPFL2019

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

César Pulgarin, Jean Arnaud Troyon, 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, Roberto Monni, Kathrin Maria Aziz-Lange, Dominik Kinschel

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

Investigations of the non-adiabatic photophysics of Cu(I)-phenanthroline complexes

Gloria Capano

Cu(I)-phenanthrolines are an important class of metal-organic molecules that exhibits much promise for solar energy harvesting and solar-driven catalysis applications. Although many experimental studies have been performed calling for high-level simulation ...

EPFL2016

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, Maninder Singh

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, Nicola Salvi, Diego Carnevale, Roberto Buratto, Daniele Mammoli, 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

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

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

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

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

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

Ultrafast electronic and vibrational relaxations in mixed-ligand dithione-dithiolato Ni, Pd, and Pt complexes

Majed Chergui, Frank van Mourik, Andrea Cannizzo, Ahmad Odeh

Ultrafast excited-state dynamics of planar Pt, Pd, and Ni dithione-dithiolato complexes were investigated by transient absorption spectroscopy on the femtosecond-picosecond timescale. All studied complexes show a common photobehaviour, although individual ...

Royal Society of Chemistry2014

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

Method for nuclear magnetic resonance (NMR) spectroscopy measurements using long-lived coherences (LLC)

Geoffrey Bodenhausen, Riddhiman Sarkar, Paul Romeo Vasos, Puneet Ahuja

A method for nuclear magnetic resonance (NMR) spectroscopy of a sample comprises preparation of the sample and carrying out an NMR spectroscopy measurement. Preparation includes excitation of long lived coherences (LLC) between the singlet state S0 and the ...

2013