Olivier Christian Bräm

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A wide variety of physical and chemical processes at the molecular level, as charge or energy transfer, solvation, electronic as well as vibrational relaxation, is at the origin of the biological functionality of proteins. The work reported in this thesis ...

Femtosecond fluorescence up-conversion, UV-Vis and IR transient absorption spectroscopy are used to study the photo-isomerization dynamics of a new type of zwitterionic photoswitch based on a N-alkylated indanylidene pyrroline Schiff base framework (ZW-NAI ...

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 ...

We report on an experimental study with UV and visible ultrafast time-gated emission and transient absorption of the early photodynamics of horse heart Cytochrome c in both ferric and ferrous redox states. A clear separation in time and energy of tryptopha ...

We present a femtosecond broad-band fluorescence up-conversion study of the vibrational relaxation dynamics of two UV chromophores, 2,5-diphenyloxazole (PPO) and para-terphenyl (pTP), pumped with a large excess of vibrational energy (>2000 cm(-1)). The ban ...

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 ...

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 ...

Femto- to picosecond excited-state dynamics of the complexes Re(L)(CO)(3)(N,N) (N,N = bpy, phen, 4,7-dimethyl-phen (dmp); L = Cl, n = 0; L = imidazole, n = 1+) were investigated using fluorescence up-conversion, transient absorption in the 650-285 nm ...

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 ...

Time-resolved fluorescence spectra from the RuN719 dye exhibit very short lifetimes (

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 ...

The fs-time-resolved study of a small UV dye in different solvents with fluorescence up-conversion and photon-echo techniques in the UV range provides new insight in cooling relaxation and solvation dynamics of non-polar molecules in polar solvents. ...

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 ...

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 = ...

We present a new photon echo set-up operating in the UV range and our 1st results of photon echo peak shift (PEPS) expts. of a small non-polar dye mol., p-terphenyl (pTP), in 3 different solvents: EtOH, MeOH, and 2-propanol. The expts. show the feasibility ...

The authors present photon echo peak shift and femtosecond fluorescence up-conversion studies of nonpolar solvation dynamics of a simple nonpolar dye p-terphenyl in EtOH and cyclohexane, using excitation in the UV range at 290 nm. The UV fluorescence up-co ...

We give an overview of our recent work on ultrafast dynamics of chemical (organic dyes, metal-complexes, colloidal quantum dots), and biological (retinal and haem proteins) systems in the liquid phase, studied with a variety of ultrafast optical techniques ...

We show a femtosecond fluorescence upconversion setup with broadband detection to measure time-resolved emission spectra in the 300-550 nm range, upon excitation between 250 and 300 nm, with a time resolution of 100 fs. We present time-resolved fluorescenc ...

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- ...

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 ...

Olivier Christian Bräm

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Ultrafast Visible and Ultraviolet Fluorescence Studies of Molecular and Biological Sytems in Solution

Coherent ultrafast torsional motion and isomerization of a biomimetic dipolar photoswitch

Real-time observation of the charge transfer to solvent dynamics

Femtosecond UV Studies of the Electronic Relaxation Processes in Cytochrome c

A femtosecond fluorescence study of vibrational relaxation and cooling dynamics of UV dyes

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

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

Ultrafast Excited-State Dynamics of Rhenium(I) Photosensitizers [Re(Cl)(CO)(3)(N,N)] and [Re(imidazole)(CO)(3)(N,N)](+): Diimine Effects

Energy transfer and relaxation mechanisms in Cytochrome c

Ultrafast fluorescence studies of dye sensitized solar cells

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

Broadband femtosecond fluorescence up-conversion and photon echo experiments in the UV

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

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

Photon echo peak shift experiments in the UV: p-terphenyl in different solvents

Ultrafast UV photon echo peak shift and fluorescence up conversion studies of non-polar solvation dynamics

Ultrafast (Bio)physical and (Bio)chemical Dynamics

Femtosecond fluorescence upconversion setup with broadband detection in the ultraviolet

Ultrafast Relaxation Dynamics of Osmium-Polypyridine Complexes in Solution

Polychromatic femtosecond fluorescence studies of metal-polypyridine complexes in solution