Pratiques spirituelles et images au tournant des xvie et xviie siècles

« Les Exercices Spirituels sont-ils illustrables ? ». Telle était la question que se posait il y a quelques années Pierre-Antoine Fabre après avoir publié un ouvrage, remarqué, sur Ignace de Loyola et « le problème de la composition du lieu dans les pratiques spirituelles et artistiques jésuites de la seconde moitié du xvie siècle ». La question n’était pas sans ironie ni provocation, y compris à l’égard de l’auteur (une thèse ne suffisait donc pas pour répondre à une telle question), qui ent..

Bulk or surface grafted silylated Ru(ii) complexes on silica as luminescent nanomaterials

A series of Ru(II) complexes with monosilylated-dipyridine ligand have been synthesized and fully characterized and were then covalently attached to silica nanoparticles. Two types of hybrids were obtained depending on the experimental procedure. In the first approach, metal complexes were incorporated inside the silica nanoparticles leaving a free hydroxylated silica surface for further functionalization. These silica based nanohybrids are similar to the well known nanoparticles encapsulating [Ru(bpy)3]2+ complexes preventing the release of the dye when used in aqueous or organic solutions. Size and luminescence properties vary throughout the series of metal complexes. The second approach leads to ruthenium(II) complexes covalently attached to the silica nanoparticle surface via hydrolysis and condensation of the ethoxysilyl group with silanol sites of Ludox type silica nanoparticles. This leads to the grafting of a monolayer for complexes with the monoethoxysilyl dipyridine ligand. In contrast, the complexes with triethoxysilyl ligands can lead to small amounts of oligomers, but their quantity is limited by the sterical constraints imposed by the molecular structure. The size of the hybrids depends on the starting particles. 29Si and 13C solid state NMR are used to characterize silica surface properties whereas TEM and SEM confirm nanosize and morphology of the hybrids. The complexes and the nanohybrids are luminescent, with variations for ruthenium(II) complexes that are covalently incorporated or grafted on the silica surfac

Ethylenediamine- and propylenediaminediacetic acid derivatives as ligands for the "fac-[M(CO)3]+" core (M = Re, 99mTc)

The reaction of Re(CO)5Cl with o- or p-N-(nitrophenyl)ethylenediaminediacetic acid (H2L1, H2L2) and o- or p-N-(nitrophenyl)propylenediaminediacetic acid (H2L3, H2L4) in methanol leads to the formation of stable anionic [Et3NH][Re(CO)3(L)]·H2O complexes 1-4. These compounds have been characterized by means of IR, mass spectrometry, elemental analysis, NMR and conductimetry, as well as X-ray crystallography for 2 and 3. The [Re(CO)3]+ moiety is coordinated via the nitrogen of the iminodiacetic acid unit and two oxygens of monodentate carboxylate groups. In each case, the nitro group of the aromatic ring remains uncoordinated. The analogous technetium-99m complexes 1' and 3' were also prepared quantitatively by the reaction of H2L1 and H2L3, respectively, with the fac-[99mTc(CO)3(H2O)3]+ precursor in ethanol. The corresponding Re and 99mTc compounds were shown to possess the same structure by means of HPLC studies. The high affinity of these ligands for the Tc(I) or Re(I) core, coupled with the easiness of their derivatization (by reduction of the nitro group in amino group), implies that the utilization of this ligand system to develop target-specific radiopharmaceuticals for diagnosis and therapy is promising

Bifunctional magnetic luminescent particles based on iron oxide nanoparticles grafted with a europium silylated bypiridine tris(β-diketonate) complex

A new highly magnetic-luminescent nanocomposites has been synthesized by grafting luminescent europium complex comprising tris(b-diketone) and bypridine ligand modified with a silylil function group (Eu[(TTA)3(Bpy-Si)] complex) on the surface of superparamagnetic iron oxide nanoparticles with 11 nm in size coated with a thin silica outer layer. The g-Fe2O3/SiO2 nanoparticles were fully characterized by ATR-FTIR, FE-SEM, HRTEM and magnetic measurements to confirm the structure of nanocomposite and the superparamagnetic behavior. Grafting with europium silylated bypiridine tris(b-diketonate) complex on nanoparticles surface was achieved by covalent bonding through triethoxysilyl groups which allows high concentration of the luminescent species. The resulting nanocomposite display superparamagnetic profile and the indirect excitation in the ultraviolet region outcomes high red luminescence intensity(at 613 nm) with narrow characteristic emission lines of Eu(III) and emission lifetime in the millisecond range. The nanocomposite is potentially useful for applications as biolabelling,imaging, bio-separation and bioassays

Introduction

De ce qui a été l’un des programmes artistiques majeurs de la première moitié du xviie siècle, l’édification par certains des plus éminents artistes de plus d’une soixantaine de retables monumentaux dans les sanctuaires des églises parisiennes, subsistent à peine aujourd’hui trois exemples à Saint-Nicolas-des-Champs, à Saint-Laurent et à Saint-Joseph des Carmes, actuelle chapelle de l’Institut catholique. Les maîtres-autels parisiens du xviie siècle, réduits à leurs vestiges architecturaux ou..

Esthétique des fluides : une introduction

L’origine de ce recueil de textes est la présence, continûment répétée, du terme de « fluidité » pour qualifier, dans les textes critiques du XIXe siècle, la peinture impressionniste et, avant tout mais pas seulement, l’art de Monet. Il est le « Raphaël de l’eau » selon Antonin Proust, dont la « prodigieuse fluidité » sera louée des origines du mouvement jusqu’aux Nymphéas. Celles-ci sont qualifiées par Louis Gillet comme « un échange d’impondérables à travers des fluides », comme la réalisat..