Publications by Amal El Nahhas

X-ray Absorption Spectroscopy of Ground and Excited Rhenium–Carbonyl–Diimine Complexes: Evidence for a Two-Center Electron Transfer

Majed Chergui, Ursula Röthlisberger, Ivano Tavernelli, Thomas James Penfold, Van Thai Pham, Amal El Nahhas, Renske Marjan van der Veen, Frederico Alves Lima

Steady-state and picosecond time-resolved X-ray absorption spectroscopy is used to study the ground and lowest triplet states of ReX(CO)(3)(bpy), X = Etpy (n = 1), Cl, or Br (n = 0). We demonstrate that the transient spectra at both the Re L3- and Br ...

Amer Chemical Soc2013

Re and Br X-ray Absorption Near-Edge Structure Study of the Ground and Excited States of [ReBr(CO)(3)(bpy)] Interpreted by DFT and TD-DFT Calculations

Amal El Nahhas, Renske Marjan van der Veen

X-ray absorption spectra of fac-[ReBr(CO)(3)(bpy)] near the Re L-3- and Br K-edges were measured in a steady-state mode as well as time-resolved at 630 ps after 355 nm laser pulse excitation. Relativistic spin-orbit time-dependent density functional theory ...

American Chemical Society2013

A wavelet analysis for the X-ray absorption spectra of molecules

Majed Chergui, Ursula Röthlisberger, Ivano Tavernelli, Thomas James Penfold, Amal El Nahhas, Marco Eli Reinhard

We present a Wavelet transform analysis for the X-ray absorption spectra of molecules. In contrast to the traditionally used Fourier transform approach, this analysis yields a 2D correlation plot in both R- and k-space. As a consequence, it is possible to ...

American Institute of Physics2013

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

Majed Chergui, Andrea Cannizzo, Amal El Nahhas, Cristina Consani, Olivier Christian Bräm

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 ...

2011

Origin of electronic absorption spectra of MLCT-excited and one-electron reduced 2,2 '-bipyridine and 1,10-phenanthroline complexes

Majed Chergui, Andrea Cannizzo, Amal El Nahhas, Cristina Consani

UV-Vis absorption spectra of one-electron reduction products and (MLCT)-M-3 excited states of [(ReCl)-Cl-I(CO)(3)-(N, N)] (N, N = 2,2'-bipyridine, bpy; 1,10-phenanthroline, phen) have been measured by low-temperature spectroelectrochemistry and UV-Vis tran ...

Elsevier2011

Ultrafast (Bio)physical and (Bio)chemical Dynamics

Majed Chergui, Frank van Mourik, Andrea Cannizzo, Amal El Nahhas, Renske Marjan van der Veen, Cristina Consani, Ahmad Ajdar Zadeh Oskouei, Gerald Auböck, Olivier Christian Bräm

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 ...

2011

Probing the Transition from Hydrophilic to Hydrophobic Solvation with Atomic Scale Resolution

Majed Chergui, Ivano Tavernelli, Paul Beaud, Thomas James Penfold, Van Thai Pham, Amal El Nahhas, Renske Marjan van der Veen, Frederico Alves Lima

Picosecond and femtosecond X-ray absorption spectroscopy is used to probe the changes of the solvent shell structure upon electron abstraction of aqueous iodide using an ultrashort laser pulse. The transient L-1,L-3 edge EXAFS at 50 ps time delay points to ...

2011

Time-Resolved Optical and X-Ray Spectroscopy of Rhenium Based Molecular Complexes

Amal El Nahhas

The photocycle of rhenium carbonyl complexes, type facial-[Re(L)(CO)3(diimine)]n [L=halide / n=0, L=4-Ethyl-pyridine (Etpy)- Imidazole (ImH) /n=+1, diimine= bpy , 10- phenanthroline (phen), 4,4'-dimethyl-2,2'-bpy (dmb)] was studied using a set of ultrafast ...

EPFL2010

Time-resolved x-ray absorption spectroscopy: Watching atoms dance

Majed Chergui, Paul Beaud, Wojciech Gawelda, Van Thai Pham, Camelia Borca, Amal El Nahhas, Renske Marjan van der Veen, Frederico Alves Lima

The introduction of pump-probe techniques to the field of x-ray absorption spectroscopy (XAS) has allowed the monitoring of both structural and electronic dynamics of disordered systems in the condensed phase with unprecedented accuracy, both in time and i ...

Iop Publishing Ltd, Dirac House, Temple Back, Bristol Bs1 6Be, England2009

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, Mirabelle Prémont-Schwarz

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