A5038967647- Advanced Chemical Physics Studies
- Radiopharmaceutical Chemistry and Applications
- Crystallography and molecular interactions
- Radioactive element chemistry and processing
- Inorganic Fluorides and Related Compounds
- Advanced Fiber Laser Technologies
- Advanced Frequency and Time Standards
- X-ray Diffraction in Crystallography
- Mechanical and Optical Resonators
- Crystallization and Solubility Studies
- Cold Atom Physics and Bose-Einstein Condensates
- Inorganic Chemistry and Materials
- Fluorine in Organic Chemistry
- Atomic and Subatomic Physics Research
- Molecular Spectroscopy and Structure
- Analytical Chemistry and Chromatography
- Solid State Laser Technologies
- Metal complexes synthesis and properties
- Electrochemical Analysis and Applications
- Machine Learning in Materials Science
- Advanced MEMS and NEMS Technologies
- Boron and Carbon Nanomaterials Research
- Chemical synthesis and alkaloids
- Organoboron and organosilicon chemistry
- Adaptive optics and wavefront sensing
Centre National de la Recherche Scientifique
2015-2024
Université Paris-Saclay
2024
Laboratoire Charles Fabry
2022-2024
Institut d’Optique Graduate School
2018-2024
Chimie et Interdisciplinarité, Synthèse, Analyse, Modélisation
2014-2023
Nantes Université
2014-2023
Systèmes de Référence Temps-Espace
2017-2022
Sorbonne Université
2017-2022
Observatoire de Paris
2020-2022
Université Paris Sciences et Lettres
2017-2020
Abstract One of the most important properties influencing chemical behavior an element is electron affinity (EA). Among remaining elements with unknown EA astatine, where one its isotopes, 211 At, remarkably well suited for targeted radionuclide therapy cancer. With At − anion being involved in many aspects current astatine labeling protocols, knowledge this prime importance. Here we report measured value to be 2.41578(7) eV. This result compared state-of-the-art relativistic quantum...
Computational chemistry currently lacks ad hoc tools for probing the nature of chemical bonds in heavy and superheavy-atom systems where consideration spin–orbit coupling (SOC) effects is mandatory. We report an implementation Quantum Theory Atoms-In-Molecules framework two-component relativistic calculations. Used conjunction with topological analysis Electron Localization Function, we show astatine (At) species that SOC significantly lowers At electronegativity boosts its propensity to...
Ab initio calculation of electronic excitation energies with chemical accuracy (ca. 1 kcal·mol-1 or 0.043 eV respect to experiment) is a long-standing challenge in structure theory. Indeed, the most advanced theories can, practice, only be used estimate vertical transition that cannot measured experimentally, whereas 0-0 requires excited-state structures and vibrations for both ground excited states, which drastically restrains number applicable methods. In this Letter, we present composite...
ConspectusAstatine (At) is the rarest on Earth of all naturally occurring elements, situated below iodine in periodic table. While only short-lived isotopes (t1/2 ≤ 8.1 h) are known, 211At object growing attention due to its emission high-energy alpha particles. Such radiation highly efficient eradicate disseminated tumors, provided that radionuclide attached a cancer-targeting molecule. The interest applications nuclear medicine translates into increasing number cyclotrons able produce it....
A cost-effective computational methodology designed to study astatine (At) chemistry in aqueous solution has been established. It is based on two-component spin–orbit density functional theory calculations and solvation using the conductor-like polarizable continuum model conjunction with specific cavities. Theoretical are confronted experimental data measured for complexation reactions between metallic forms of (At+ AtO+) inorganic ligands (Cl−, Br− SCN−). For each reaction, both 1 ∶ 2...
Abstract 211 At is a most promising radionuclide for targeted alpha therapy. However, its limited availability and poorly known basic chemistry hamper use. Based on the analogy with iodine, labelling performed via astatobenzoate conjugates, but in vivo deastatination occurs, particularly when conjugates are internalized cells. Actually, chemical or biological mechanism responsible unknown. In this work, we show that C−At “organometalloid” bond can be cleaved by oxidative dehalogenation...
Abstract It is generally assumed that astatide (At − ) the predominant astatine species in basic aqueous media. This assumption questioned non‐complexing and non‐reductive solutions by means of high‐pressure anion‐exchange chromatography. Contrary to what usually believed, found be a minor at pH=11. A different species, which also bears single negative charge, becomes when pH increased beyond 7. Using competition experiments, an equilibrium constant value 10 −6.9 has been determined for...
A combined experimental and theoretical approach is used to define astatine (At) speciation in acidic aqueous solution answer the two main questions raised from literature data: does At(0) exist what chemical form of At(+III), if it exists. The considers that a given species characterized by its distribution coefficient (D) experimentally determined biphasic system. change arising conditions observed D value. involves quasi-relativistic quantum chemistry calculations. results show At at...
This work aims to resolve some controversies about astatine(III) hydroxide species present in oxidant aqueous solution. AtO+ is the dominant existing under oxidizing and acidic pH conditions. consistent with high-performance ion-exchange chromatography data showing existence of one holding positive charge. A change speciation occurs as changes from 1 4, while remaining Dynamic experiments resins evidence a neutral witnessed by its elution void volume. Batch-experiments using competition...
We present an original formulation of the electron localization function (ELF) in field relativistic two-component DFT calculations. Using I2 and At2 species as a test set, we show that ELF analysis is suitable to evaluate spin-orbit effects on electronic structure. Beyond these examples, this approach opens up new opportunities for bonding large molecular systems involving heavy superheavy elements.
The main-group 6p elements did not receive much attention in the development of recent density functionals. In many cases it is still difficult to choose among modern ones a relevant functional for various applications. Here, we illustrate case astatine species (At, Z = 85) and report first, quite complete, benchmark study on several properties concerning such species. Insights geometries, transition energies thermodynamic set 19 species, which reference experimental or theoretical data has...
Abstract Fluorination is commonly exercised in compound property optimization. However, the influence of fluorination on hydrogen‐bond (HB) properties adjacent functional groups, as well HB‐accepting capacity fluorine itself, still not completely understood. Although formation OH⋅⋅⋅F intramolecular HBs (IMHBs) has been established for conformationally restricted fluorohydrins, such interaction flexible compounds remained questionable. Herein demonstrated first time—and contrast to earlier...
Fragmentation pathways of unsubstituted and substituted benzylpyridinium compounds were investigated using mass-analysed kinetic energy (MIKE) technique in combination with high level quantum chemical calculations the gas phase. Fast atom bombardment (FAB) source was used for ionisation studied compounds. The formation both benzylium tropylium species investigated. Hybrid Hartree-Fock/Density Functional Theory have been performed to assess geometries energies transition states intermediates....
Rational modulations of molecular interactions are significant importance in compound properties optimization. We have previously shown that fluorination conformationally rigid cyclohexanols leads to attenuation their hydrogen-bond (H-bond) donating capacity (designated by pKAHY ) when OH⋅⋅⋅F intramolecular (IMHB) occur, as opposed an increase due the fluorine electronegativity. This work has now been extended a wider range aliphatic β-fluorohydrins with increasing degrees conformational...
The electrochemical reduction of sensitive sulfonamides is described. addition a benzoyl group on the nitrogen atom facilitates reductive cleavage preventing β-fragmentation and epimerization. This strategy was successfully applied to cyclopropylamine α-amino stannanes.
The nature of chemical bonds in heavy main-group diatomics is discussed from the viewpoint effective bond orders, which are computed spin-orbit wave functions resulting configuration interaction calculations. reliability relativistic correlated obtained such two-step coupling frameworks assessed by benchmark studies spectroscopic constants with respect to either experimental data, or state-of-the-art fully I2, At2, IO(+), and AtO(+) species considered, differences similarities between...
Abstract The effect of fluorination on the conformational and hydrogen‐bond (HB)‐donating properties a series benzyl alcohols has been investigated experimentally by IR spectroscopy theoretically with quantum chemical methods (ab initio (MP2) DFT (MPWB1K)). It was found that o ‐fluorination generally resulted in an increase HB acidity hydroxyl group, whereas decrease observed upon , o′ ‐difluorination. Computational analysis showed landscapes title compounds are strongly influenced presence...
The properties of halides from the lightest, fluoride (F(-)), to heaviest, astatide (At(-)), have been studied in water using a polarizable force-field approach based on molecular dynamics (MD) simulations at 10 ns scale. selected explicitly treats cooperativity within halide-water hydrogen bond networks. parameters adjusted ab initio data anion/water clusters computed relativistic Möller-Plesset second-order perturbation theory level theory. anion static polarizabilities two heaviest...
If astatine is generally a stronger halogen-bond donor than iodine, an inversion sometimes observed owing to the spin–orbit coupling.
The electronic structure of the XO and XO(+) (X = I, At) species, as well that a AtO(+)-H2O complex have been investigated using relativistic wave-function theory density functional (DFT)-based approximations (DFAs). n-electron valence state perturbation method with perturbative inclusion spin-orbit coupling including polarization effects (SO-NEVPT2) was shown to yield transition energies within 0.1 eV reference four-component intermediate Fock-space coupled cluster (DC-IHFSCCSD) at...