Publications de Olivier Christian Bräm

Ultrafast Broadband Fluorescence Up-conversion Study of the Electronic Relaxation of Metalloporphyrins

Majed Chergui, Andrea Cannizzo, Olivier Christian Bräm

We present a systematic study of the ultrafast fluorescence with broadband detection and similar to 110 fs resolution of 5,10,15,20-tetraphenylporphin (TPP) and 2,3,7,8,12,13,17,18-oc-taethylporphin (OEP), with open 3d-shell metals. We also revisit the cas ...

AMER CHEMICAL SOC2019

Dual Luminescence, Interligand Decay, and Nonradiative Electronic Relaxation of Cyclometalated Iridium Complexes in Solution

Majed Chergui, Andrea Cannizzo, Enrico Pomarico, Olivier Christian Bräm, Mahsa Silatani

Femtosecond broadband photoluminescence studies are presented for Ir(ppy)(3) (Ir1), Ir(ppy)(2)(pic) (Ir2), Ir(ppy)(2)(bpy)(PF6) (Ir3), Ir(ppz)(3) (Ir4), and Ir(ppz)(2)dipy (Ir5) (where ppy = 2-phenylpyridine, pic = picolinate, bpy = 2,2'-bipyridine, ppz = ...

American Chemical Society2016

A cascade through spin states in the ultrafast haem relaxation of met-myoglobin

Majed Chergui, Frank van Mourik, Cristina Consani, Gerald Auböck, Olivier Christian Bräm

We report on a study of the early relaxation processes of met-Myoglobin in aqueous solution, using a combination of ultrafast broadband fluorescence detection and transient absorption with a broad UV-visible continuum probe at different pump energies. Reco ...

American Institute of Physics2014

Ultrafast Relaxation Dynamics of Osmium-Polypyridine Complexes in Solution

Mohammad Khaja Nazeeruddin, Majed Chergui, Andrea Cannizzo, Olivier Christian Bräm

We present steady-state absorption and emission spectroscopy and femtosecond broadband photoluminescence up-conversion spectroscopy studies of the electronic relaxation of Os(dmbp)(3) (Os1) and Os(bpy)(2)(dpp) (Os2) in ethanol, where dmbp is 4,4'-dimethyl- ...

American Chemical Society2013

Ultrafast Solvent-Assisted Electronic Level Crossing in 1-Naphthol

Majed Chergui, Olivier Christian Bräm, Mirabelle Prémont-Schwarz

Wiley-Blackwell2013

Solvent Induced Luminescence Quenching: Static and Time-Resolved X-Ray Absorption Spectroscopy of a Copper(I) Phenanthroline Complex

Majed Chergui, Ursula Röthlisberger, Ivano Tavernelli, Thomas James Penfold, Gloria Capano, Marco Eli Reinhard, Frederico Alves Lima, Mercedes Hannelore Rittmann-Frank, Jochen Rittmann, Olivier Christian Bräm

We present a static and picosecond X-ray absorption study at the Cu K-edge of bis(2,9-dimethyl-1,10-phenanthroline)copper(I) (Cu(dmp)(2); dmp = 2,9-dimethyl-1,10-phenanthroline) dissolved in acetonitrile and dichloromethane. The steady-state photolumi ...

Amer Chemical Soc2013

Real-time observation of the charge transfer to solvent dynamics

Majed Chergui, Andrea Cannizzo, Olivier Christian Bräm

Intermolecular electron-transfer reactions have a crucial role in biology, solution chemistry and electrochemistry. The first step of such reactions is the expulsion of the electron to the solvent, whose mechanism is determined by the structure and dynamic ...

Nature Publishing Group2013

Ultraviolet transient absorption, transient grating and photon echo studies of aqueous tryptophan

Majed Chergui, Andrea Cannizzo, Cristina Consani, Ahmad Ajdar Zadeh Oskouei, Olivier Christian Bräm

We compare UV transient grating (TG) experiments of aqueous tryptophan with transient absorption (TA) and fluorescence up-conversion measurements. The TG and TA signals show a bi-exponential rise with sub-ps and ps time constants, which are consistent with ...

Elsevier2013

Polychromatic femtosecond fluorescence studies of metal-polypyridine complexes in solution

Majed Chergui, Andrea Cannizzo, Olivier Christian Bräm, Ahmed Maher Fahmy El-Zohry

Femtosecond-resolved broadband fluorescence studies are reported for M(bpy)(3) (M = Fe, Ru), RuN3 and RuN719 complexes in solution. We investigated the pump wavelength dependence of the fluorescence of aqueous Fe(bpy)(3) and the solvent and li ...

2012

Energy transfer and relaxation mechanisms in Cytochrome c

Majed Chergui, Frank van Mourik, Andrea Cannizzo, Cristina Consani, Olivier Christian Bräm

Using broadband UV-vis femtosecond transient absorption and fluorescence up-conversion, we investigate the interaction between the haem moiety of ferric and ferrous Horse heart Cytochrome c and its single Tryptophan (Trp) residue and the energy dissipation ...

Elsevier2012