Extensional and Intensional Strategies

This paper is a contribution to the theoretical foundations of strategies. We first present a general definition of abstract strategies which is extensional in the sense that a strategy is defined explicitly as a set of derivations of an abstract reduction system. We then move to a more intensional definition supporting the abstract view but more operational in the sense that it describes a means for determining such a set. We characterize the class of extensional strategies that can be defined intensionally. We also give some hints towards a logical characterization of intensional strategies and propose a few challenging perspectives

Magnetic and luminescent coordination networks based on imidazolium salts and lanthanides for sensitive ratiometric thermometry

The synthesis and characterization of six new lanthanide networks [Ln(L)(ox)(H2O)] with Ln = Eu3+, Gd3+, Tb3+ , Dy3+ , Ho3+ and Yb3+ is reported. They were synthesized by solvo-ionothermal reaction of lanthanide nitrate Ln(NO3)(3)center dot xH(2)O with the 1,3-bis(carboxymethyl)imidazolium [HE] ligand and oxalic acid (H(2)ox) in a water/ethanol solution. The crystal structure of these compounds has been solved on single crystals and the magnetic and luminescent properties have been investigated relying on intrinsic properties of the lanthanide ions. The synthetic strategy has been extended to mixed lanthanide networks leading to four isostructural networks of formula [Tb1-xEux(L)(ox)(H2O)] with x = 0.01, 0.03, 0.05 and 0.10. These materials were assessed as luminescent ratiometric thermometers based on the emission intensities of ligand, Tb3+ and Eu3+ . The best sensitivities were obtained using the ratio between the emission intensities of Eu3+ (D-5(0) -> F-7(2) transition) and of the ligand as the thermometric parameter. [Tb0.97Eu0.03 (L)(ox)(H2O)] was found to be one of the best thermometers among lanthanide-bearing coordination polymers and metal-organic frameworks, operative in the physiological range with a maximum sensitivity of 1.38%.K-1 at 340 K

Synthèse de nanoparticules hybrides organiques-inorganiques a propriété non linéaire quadratique et bi stabilité optique.

Dans ce manuscrit, nous présentons la synthèse et la caractérisation de nanoparticules hybrides Organiques-Inorganiques ayant des propriétés non linéaires (ONL) quadratiques et de nanoparticules possédant des propriétés de bistabilité optique. La stratégie adoptée, au cours de ce travail, repose sur une approche bottom-up de la synthèse de composés d intercalations inorganiques lamellaires de type MPS3 (où M = Mn2+ , Ni2+) comportant des molécules organiques invitées de type push-pull . Ce développement fait suite à des travaux antérieurs, qui avaient montré que la juxtaposition de feuillets hôtes MPS3 et de dérivés de type stilbazolium pouvait donner naissance à des propriétés de Génération de Second Harmonique dues à la formation d agrégats J. En effet, ces agrégats sont responsables de l arrangement non-centrosymétrique des chromophores au sein des feuillets et donc à l origine des propriétés optiques observées. Ainsi, deux approches différentes ont été utilisées pour générer ces nanoparticules : une première repose sur l utilisation de micelles inverses (surfactants) et une seconde sur l utilisation de résine échangeuse d ionsThis PhD deals with the synthesis and characterization of Hybrid Inorganic-Organic nanoparticles possessing strong second-order Optical Non-Linearity and a lesser extent of nanoparticles exhibiting optical bistability. The strategy for building up NLO materials is based on a bottom-up approach of the synthesis of layered inorganic intercalation compounds of the MPS3 type (M=Mn2+, Ni2+) containing push-pull organic guest chromophores. The thesis is a continuation of previous work carried out in our laboratory on traditional bulk crystalline materials, which had shown that juxtaposing on the molecular scale centrosymmetric MPS3 host slabs and stilbazolium derivatives gave birth to second Harmonic Generation due to the formation of J aggregates between the inorganic slabs, that were responsible for the non-centrosymmetric arrangement of the push-pull chromophores. Two different procedures were used to obtain nanoparticles : a first with reverse micelles (surfactants) and a second with cation exchange resinORSAY-PARIS 11-BU Sciences (914712101) / SudocSudocFranceF

Top-m identification for linear bandits

International audienceMotivated by an application to drug repurposing, we propose the first algorithms to tackle the identification of the m ≥ 1 arms with largest means in a linear bandit model, in the fixed-confidence setting. These algorithms belong to the generic family of Gap-Index Focused Algorithms (GIFA) that we introduce for Top-m identification in linear bandits. We propose a unified analysis of these algorithms, which shows how the use of features might decrease the sample complexity. We further validate these algorithms empirically on simulated data and on a simple drug repurposing task

Top-m identification for linear bandits

International audienceMotivated by an application to drug repurposing, we propose the first algorithms to tackle the identification of the m ≥ 1 arms with largest means in a linear bandit model, in the fixed-confidence setting. These algorithms belong to the generic family of Gap-Index Focused Algorithms (GIFA) that we introduce for Top-m identification in linear bandits. We propose a unified analysis of these algorithms, which shows how the use of features might decrease the sample complexity. We further validate these algorithms empirically on simulated data and on a simple drug repurposing task

Discrete versus 1D Compounds based on Pentagonal Bipyramid Coordination Geometries: A Matter of Solubility?

International audienceA series of heterometallic compounds based on the association of trans-dicyanido Cr(III) complex [Cr(L)(CN)2]K ⋅ 2H2O and several divalent [MnII(H2Ln)Cl2] heptacoordinated complexes, where Ln stands for pentadentate ligands featuring a planar N3O2 coordination pocket and various substituents (NH2, cyclohexyl, S,S-mandelic), is described. A dinuclear compound [Cr(L)(CN)2M(H2L2)] and 1D coordination polymers of general formula [Cr(L)(CN)2M(H2Ln)]X (X=PF6− or [Cr(L)(CN)2]−) were rationally prepared by a simple adjustment of the Cr : M stoichiometry for R=NH2 or tuning the solvent mixtures to promote the crystallization of discrete complexes or chains. The crystal structures, phase purities and magnetic properties of all the compounds are reported

Synthesis and Second Harmonic Generation microscopy of nonlinear optical efficient hybrids nanoparticles embedded in polymer films. Evidence for Intra and Inter nanoparticles orientational synergy

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Post-synthesis modification of the aurivillius phase Bi2SrTa2O9 via in situ microwave-assisted "Click Reaction".

International audienceA new strategy for the functionalization of layered perovskites is presented, based on the in situ post-synthesis modification of a prefunctionalized phase by copper(I)-catalyzed alkyne–azide cycloaddition (CuAAC). The microwave-assisted protonation and grafting of an alkyne alcohol provides the alkyne-functionalized precursor within a few hours, starting from Bi2SrTa2O9. The subsequent microwave-assisted in situ “click reaction” allows the post-synthesis modification of the precursor within ∼2 h, providing a layered perovskite functionalized by an alcohol-grafted 1,4-disubstituted-1H-1,2,3-triazole. Two compounds are described here, bearing an aliphatic and an aromatic substituent, which illustrates the general application of the method. This work opens new perspectives for the functionalization of layered perovskites, going beyond mere insertion/grafting reactions, and thus broadens the design possibilities and the range of applications of these hybrid systems

Efficient Microwave-Assisted Functionalization of the Aurivillius-Phase Bi2SrTa2O9.

International audienceA new method of acidification and subsequent functionalization of the Aurivillius-phase Bi2SrTa2O9 (BST), using microwave irradiation, was developed. This method enables to obtain hybridized phases from layered BST. Functionalization of BST by various kinds of amines and diamines can be achieved in a few hours only, compared to much longer time (over a week) using conventional heating. Good crystallinity of the compounds is kept. In addition, a microwave-assisted preintercalation strategy was developed, allowing inserting new amines (bearing cyclic or aromatic groups) between the oxide layers previously unseen in this type of compound. This work opens new perspectives for the fast and easy functionalization of layered oxides with more elaborated molecules

Elaboration of Luminescent and Magnetic Hybrid Networks Based on Lanthanide Ions and Imidazolium Dicarboxylate Salts: Influence of the Synthesis Conditions

The syntheses and characterization of four new hybrid coordination networks based on lanthanide ions (Ln = Nd, Sm) and 1,3-carboxymethylimidazolium (L) salt in the presence of oxalic acid (H2ox) are reported. The influence of the synthesis parameters, such as the nature of the lanthanide ion (Nd3+ or Sm3+), the nature of the imidazolium source (chloride [H2L][Cl] or zwitterionic [HL] form) and the presence or not of oxalic acid (H2ox), is discussed. In the presence of oxalic acid, the samarium salt gives only one compound [Sm(L)(ox)(H2O)]·H2O, whatever the nature of the imidazolium ligand, while the neodymium salt leads to three different compounds, [Nd(L)(ox)(H2O)]·H2O, [Nd(L)(ox)0.5(H2O)2][Cl] or [Nd2(L)2(ox)(NO3)(H2O)3][NO3], depending on the imidazolium ligand. In the absence of oxalic acid, gels are obtained, except for the reaction between the neodymium salt and [H2L][Cl], which leads to [Nd(L)(ox)(H2O)]·H2O. All compounds crystallized and their structures were determined by single crystal diffraction. The description of these new phases was consistently supported by ancillary techniques, such as powder X-ray diffraction, thermal analyses and UV-visible-near infrared spectroscopy. The luminescent and magnetic properties of the three pure compounds [Sm(L)(ox)(H2O)]·H2O, [Nd(L)(ox)(H2O)]·H2O and [Nd2(L)2(ox)(NO3)(H2O)3][NO3] were also studied