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Publications associées (28)

Double-bond delocalization in non-alternant hydrocarbons induces inverted singlet-triplet gaps

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

Molecules where the first excited singlet state is lower in energy than the first excited triplet state have the potential to revolutionize OLEDs. This inverted singlet-triplet gap violates Hund's rule and currently there are only a few molecules which are ...

ROYAL SOC CHEMISTRY2023

Double-bond delocalization in non-alternant hydrocarbons induces inverted singlet-triplet gaps

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

ROYAL SOC CHEMISTRY2023

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

Bacterial inactivation in sunlit surface waters is dominated by reactive species that emanate from the synergy between light, iron, and natural organic matter

César Pulgarin, Stefanos Giannakis, Jun Ma, Da Wang, Shuang Song

In this study, the synergistic and antagonistic effects of Fe species and coexisting natural organic matter (NOM) on the efficacy of solar light disinfection of water are investigated. Different initial iron species (Fe2+/Fe3+) and naturalorganic matter ty ...

Elsevier2023

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

Optical properties and photochemical production of hydroxyl radical and singlet oxygen after ozonation of dissolved organic matter

Frank Jonathan Leresche, Urs von Gunten

This study focuses on the effects of ozonation on the optical and photochemical properties of dissolved organic matter (DOM). Upon ozonation, a decrease in light absorption properties of DOM was observed concomitantly with a large increase in singlet oxyge ...

ROYAL SOC CHEMISTRY2021

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

Trisubstituted geminal diazaalkene derived transient 1,2-carbodications

Shubhajit Das

The coulombic repulsion between two adjacent cation centres of 1,2-carbodications is known to decrease with pi- and/or n-donor substituents by a positive charge delocalization. Here we report the delocalization of the positive charge of transient 1,2-carbo ...

Royal Society of Chemistry2020

Copper(I) Based Photoredox Chemistry

Murat Alkan

Photoredox catalysis has become a powerful tool for chemists. However, the reliance on expensive Ir and Ru based photoredox catalysts (PC) motivates research for more sustainable options. Copper complexes based on favorable photophysical properties, high a ...

EPFL2020

Kinetic modeling of lag times during photo-induced inactivation of E. coli in sunlit surface waters: Unraveling the pathways of exogenous action

César Pulgarin, Jean Arnaud Troyon, Stefanos Giannakis

This work presents a kinetic analysis of the exogenous photo-induced disinfection of E. coli in natural waters. Herein, the inactivation of bacteria by light and photo-generated transient species, i.e., hydroxyl radical (HO center dot), excited triplet sta ...

PERGAMON-ELSEVIER SCIENCE LTD2019

Effects of Ozone on the Photochemical and Photophysical Properties of Dissolved Organic Matter

Silvio Canonica, Frank Jonathan Leresche, Urs von Gunten

This study focused on the effects of ozonation on the photochemical and photophysical properties of dissolved organic matter (DOM). Upon ozonation, a decrease in DOM absorbance was observed in parallel with an increase in singlet oxygen (O-1(2)) and fluore ...

AMER CHEMICAL SOC2019

Palladium-Catalyzed Synthesis of Ketenimines from Isocyanides and Synthetic Studies Towards the Total Synthesis of Mersilongine

Mathias Mamboury

In the first chapter of this thesis, the development of two new reactions for the synthesis of vinyl ketenimines and alpha-oxo-ketenimines from isocyanides is presented. These palladium-catalyzed transformations both feature an isocyanide insertion / beta- ...

EPFL2019

Divergent Synthesis of Densely Substituted Arenes and Pyridines via Cyclotrimerization Reactions of Alkynyl Triazenes

Kay Severin, Florian Gérald Abela, Nicolai Cramer, Frederick Mark Chadwick, Jin Fay Tan, Carl Thomas Bormann

Densely substituted fused aromatic triazenes can be prepared by [2 + 2 + 2] cyclotrimerization reactions of 1-alkynyl triazenes. The Cp*Ru-catalyzed cyclization proceeds well with both simple alkynyl triazenes and tethered 1-diynyl triazenes. Attractively, ...

2019

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

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

Ozonation of Para-Substituted Phenolic Compounds Yields p-Benzoquinones, Other Cyclic α,β-Unsaturated Ketones, and Substituted Catechols

Peter Rudolf Tentscher, Urs von Gunten

Phenolic moieties are common functional groups in organic micropollutants and in dissolved organic matter, and are exposed to ozone during drinking water and wastewater ozonation. Although unsubstituted phenol is known to yield potentially genotoxic p-benz ...

2018

Developing Reactions of Strained Rings : Enantioselective Desymmetrization of meso-Diaminocyclopropanes and Annulation of Donor-Acceptor Aminocyclobutanes

Daniele Perrotta

Carbo- and heterocyclic structures containing nitrogen-substituted stereocenters are recurrent structural motifs in natural and bioactive compounds, therefore constituting a privileged class of synthetic targets. In this regard, substituted three- and four ...

EPFL2018

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

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

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