A5063766768- DNA and Nucleic Acid Chemistry
- Advanced Chemical Physics Studies
- Photochemistry and Electron Transfer Studies
- Spectroscopy and Quantum Chemical Studies
- Mass Spectrometry Techniques and Applications
- Chemical and Physical Properties in Aqueous Solutions
- Porphyrin and Phthalocyanine Chemistry
- Crystallization and Solubility Studies
- X-ray Diffraction in Crystallography
- Various Chemistry Research Topics
- Metal complexes synthesis and properties
- Metabolomics and Mass Spectrometry Studies
- Analytical Chemistry and Chromatography
- Molecular Junctions and Nanostructures
- Radical Photochemical Reactions
- Free Radicals and Antioxidants
- Iron oxide chemistry and applications
- Electron and X-Ray Spectroscopy Techniques
- Advanced biosensing and bioanalysis techniques
- Synthesis and Properties of Aromatic Compounds
- Molecular Spectroscopy and Structure
- Metal-Catalyzed Oxygenation Mechanisms
- CO2 Reduction Techniques and Catalysts
- Molecular spectroscopy and chirality
- Organic Light-Emitting Diodes Research
Sciensano (Belgium)
2024-2025
Institut Scientifique de Santé Publique
2025
Université Libre de Bruxelles
2011-2024
Institute of Spectroscopy
2020
University of California, San Diego
2010-2017
Vrije Universiteit Brussel
2013
Laboratoire de Chimie et Physique Quantiques
2010
Environmental Molecular Sciences Laboratory
2010
University of Liège
2006
Specialized computational chemistry packages have permanently reshaped the landscape of chemical and materials science by providing tools to support guide experimental efforts for prediction atomistic electronic properties. In this regard, structure played a special role using first-principle-driven methodologies model complex processes. Over past few decades, rapid development computing technologies tremendous increase in power offered unique chance study transformations sophisticated...
Efficient excited-state electron transfer between an iron(III) photosensitizer and organic donors was realized with green light irradiation. This advance enabled by the use of previously reported iron photosensitizer, [Fe(phtmeimb)2]+ (phtmeimb = {phenyl[tris(3-methyl-imidazolin-2-ylidene)]borate}, that exhibited long-lived luminescent ligand-to-metal charge-transfer (LMCT) excited states. A benchmark dehalogenation reaction investigated yields exceed 90% enhanced stability relative to...
Results of ab initio molecular dynamics (AIMD) simulations (density functional theory+PBE96) the waters in hydration shells surrounding Zn2+ ion (T≈300 K, ρ≈1 gm/cm3) are compared to using a combined quantum and classical [AIMD/molecular mechanical (MM)] approach. Both classes were performed with 64 solvating water molecules (∼15 ps) used same methods electronic structure calculation (plane-wave basis set, time steps, effective mass, etc.). In AIMD/MM calculation, only six included (QM)...
His-aromatic complexes, with the His located above aromatic plane, are stabilized by π-π, δ(+)-π and/or cation-π interactions according to whether is neutral or protonated and partners in stacked T-shape conformations. Here we attempt probe relative strength of these as a function geometry protonation state, gas phase, water protein-like environments (acetone, THF CCl4), means quantum chemistry calculations performed up second order Møller-Plesset pertubation theory. Two sets conformations...
Vertical ionization potentials (IPs) of nucleobases embedded in a fully solvated DNA fragment (12-mer B-DNA + 22 sodium counterions 5760 water molecules equilibrated to 298 K) have been calculated using combined quantum mechanical molecular mechanics (QM/MM) approach. Calculations the vertical IP anion Cl(-) are reported that support accuracy application QM/MM method this problem. It is shown pi nucleotide HOMO origin for emitted electron localized on base by hydration structure surrounding...
Low-energy electrons (LEEs) play an important role in nanolithography, atmospheric chemistry, and DNA radiation damage. Previously, the cleavage of specific chemical bonds triggered by LEEs has been demonstrated a variety small organic molecules such as halogenated benzenes nucleobases. Here we present strategy that allows for first time to visualize electron-induced dissociation single within complex, but well-defined self-assembled nanostructures. We employ atomic force microscopy image...
The electronic structure of DNA is determined by its nucleotide sequence, which for instance exploited in molecular electronics. Here we demonstrate that also the strand breakage induced low-energy electrons (18 eV) depends on sequence. To determine absolute cross sections electron single breaks specific 13 mer oligonucleotides used atomic force microscopy analysis origami based nanoarrays. We investigated sequences 5′-TT(XYX)3TT with X = A, G, C and Y T, BrU 5-bromouracil found break...
The ionization of the four DNA bases is investigated by means ab initio calculations. Accurate values gas-phase vertical and adiabatic potentials (IP) are obtained at MP2/6-31G(2d(0.8,alpha(d)),p) level theory. need introducing extra polarization to standard 6-31G(d,p) basis set demonstrated test calculations an optimal value alpha(d) = 0.1 obtained. Ionization electronically excited radical cations also considered. low-lying states characterized for first time. topology corresponding...
Herein, we report on the structure and dynamics of aqueous Ca(2+) system studied by using ab initio molecular (AIMD) simulations. Our detailed study revealed formation well-formed hydration shells with characteristics that were significantly different to those bulk water. To facilitate a robust comparison state-of-the-art X-ray absorption fine (XAFS) data, employ 1st principles MD-XAFS procedure directly compare simulated experimental XAFS spectra. A data for recently reported Zn(2+),...
The identification of reaction mechanisms unique to the iron, ruthenium, and iridium PS represents progress towards long-sought goal utilizing earth-abundant, first-row transition metals for emerging energy environmental applications.
First-principles dynamics simulations (DFT, PBE96, and PBE0) electron scattering calculations (FEFF9) provide near-quantitative agreement with new existing XAFS measurements for a series of transition-metal ions interacting their hydration shells via complex mechanisms (high spin, covalency, charge transfer, etc.). This analysis does not require either the development empirical interparticle interaction potentials or structural models hydration. However, it provides consistent parameter-free...
We assess the pros and cons of a large panel DFT exchange-correlation functionals for prediction electronic structure hydrogen-rich peptide radicals formed after electron attachment on protonated peptide. Indeed, despite its importance in understanding chemical changes associated with reduction step, question site an and, more generally, reduced species gas phase through electron-induced dissociation (ExD) processes mass spectrometry is still matter debate. For which several positive groups...
We investigate possible mutations in the genetic code induced by cisplatin with an approach combining molecular dynamics (MD) and hybrid quantum mechanics/molecular mechanics (QM/MM) calculations. Specifically, impact of platination on natural tautomeric equilibrium guanine–cytosine (GC) base pairs is assessed to disclose role played non-canonical forms anti-tumour activity. To obtain valuable predictions, main interactions present a real DNA environment, namely hydration stacking, are...
A detailed photophysical investigation of two dinuclear ruthenium(ii) complexes is reported. The metallic centers were coordinated to a bis-2,2'-bipyridine bridging ligand, connected either through the para (Lp, Dp) or meta position (Lm, Dm). results obtained herein compared prototypical [Ru(bpy)3]2+ parent compound. formation was accompanied by expected increase in molar absorption coefficients, i.e. 12 000 M-1 cm-1, 17 and 22 cm-1 at lowest energy MLCTmax transition for [Ru(bpy)3]2+, Dm Dp...
Low energy electron-attachment-induced damage in DNA, where dissociation channels may involve multiple bonds including complex bond rearrangements and significant nuclear motions, is analyzed here. Quantum mechanics/molecular mechanics (QM/MM) calculations reveal how of electron density after vertical attachment modulate the position dynamics atomic nuclei DNA. The motions elongation P-O (P-O(3') P-O(5')) C-C (C(3')-C(4') C(4')-C(5')) for which acquired kinetic becomes high enough so that...
In view of preparing Cu polynuclear complexes with dipyrromethene ligands, the mononuclear [Cu(II)(dipy)2] (dipyH = 5-phenyldipyrromethene) and [Cu(II)(dpdipy)2] (dpdipyH 1,5,9-triphenyldipyrromethene) have been prepared characterized by X-ray crystallography, mass spectrometry EPR spectroscopy. Their peculiar redox spectroscopic (absorption/emission) behaviours are discussed. contrast to CuII 1,1′-bidypyrrin, reduction electrolysis leads decomposition products on a time scale few hours....
Two new cyclometalated Ir(III) diimine complexes were used as photosensitizers for homogeneous hydrogen evolution reaction (HER). These characterized by electrochemistry, ultraviolet-visible absorption, time-resolved and steady-state photoluminescence spectroscopy well theoretical methods. The metal-ligand-to-ligand charge transfer character of their lowest excited state was shown to be competent efficient H2 photoproduction in the presence [Co(dmgH)2(py)Cl] catalyst, triethanolamine...
Aqua/hydroxo mononuclear Al3+ species coordinated by F− in aqueous solution are investigated using density functional theory (DFT B3LYP/6-311++G(d,p)) and the polarized continuum model (PCM). Optimized gas-phase geometries have been obtained for AlF(OH)n(H2O)m(2−n)+ which n = 0, 1, 2, or 3 while (n + m) 3, 4, 5. Analysis of Al−F, Al−O, O−H bond lengths Al, F, O, H natural charges these complexes reveals clear trends that suggest increased acidity with decreasing coordination number (CN)...
Abstract The hypothetical protection of genes from oxidative damage provided by the G-rich telomeric overhangs located at end chromosomes, which consist, in humans, single strands TTAGGG sequence repeats, is investigated here. First principle Møller-Plesset perturbation theory calculations reveal that human telomere particularly prone to oxidation and can act as a profound hole trap deep five consecutive guanines. In addition, we show dependence very important modifications induce crucial...
The Car-Parrinello-based molecular dynamics (CPMD) method was used to investigate the ion-pairing behavior between Cl(-) and Al(3+) ions in an aqueous AlCl(3) solution containing 63 water molecules. A series of constrained simulations carried out at 300 K for up 16 ps each, with internuclear separation (r(Al-Cl)) ion one held constant. calculated potential mean force (PMF) Al(3+)-Cl(-) pair shows a global minimum r(Al-Cl) = 2.3 Å corresponding contact (CIP). Two local minima assigned...