Examination of Indium Triphospholyls as Precursors for Nanoparticle Synthesis

The synthesis and characterization of the new compounds K(P3C2R2) [R=Ad (2), sBu (3)] and In(P3C2R2) [R=Ad (4), Mes (5)] are described. Further, the synthesis of indium nanoparticles via a single‐source precursor approach using In(1,2,4‐P3C2tBu2) (1) as precursor is reported. These nanoparticles were characterized by TEM, HRTEM, EDX, XRD, NMR, and optical spectroscopy. New compounds of the type M(1,2,4‐P3C2R2) (M=K, In, R=Ad, sBu, Mes) were synthesized, characterized, and examined in view of their use as precursors for indium‐based nanoparticles

Stoichiometry-controlled FeP nanoparticles synthesized from a single source precursor

Phase-pure FeP nanoparticles (NPs) have been synthesized through low temperature thermolysis of the single source precursor [(CO)4Fe(PH3)]. Examination of the mechanism demonstrates the central role of the labile CO ligands and the weak P–H bonds to yield stoichiometry controlled FeP materials

Homo- et hétéropolymetallocènes du groupe 14 à espaceurs conjugués

TOULOUSE3-BU Sciences (315552104) / SudocSudocFranceF

Complexes de ruthénium à ligand phosphinidène terminal (synthèse et réactivité)

TOULOUSE3-BU Sciences (315552104) / SudocSudocFranceF

New generation of magnetic and luminescent nanoparticles for in-vivo real-time imaging

International audienceA new generation of optimized contrast agents is emerging, based on metallic nanoparticles (NPs) and semiconductor nanocrystals (NCs) for respectively magnetic resonant imaging (MRI) and near-infra-red (NIR) fluorescent imaging techniques. Compared with established contrast agents such as iron oxide NPs or organic dyes, these NPs benefit from several advantages: their magnetic and optical properties can be tuned through size, shape and composition engineering, their efficiency can excess by several order of magnitude that one of contrast agents clinically used, their surface can be modified to incorporate specific targeting agents and antifolding polymers to increase the blood circulation time and the tumor recognition, they can possibly be integrated in complex architecture to yield multimodal imaging agents. In this review, we will report the materials of choice based on the understanding of the physics basics of NIR and MRI techniques and their corresponding syntheses as NPs. Surface engineering, water transfer, and specific targeting will be highlighted prior to their first use for in-vivo real-time imaging. Highly efficient NPs, safer in use and target specific are likely to be entering clinical applications in a near future

Beyond hydrophobisation: Deciphering the surprising reactivity of trimethylsilyl reagents towards graphene oxide

International audienceTrimethylsilylation of metal oxide surfaces (silica, titania…) is a common way to empower the handled supports with outstanding stability. This hydrophobisation prevailed in vital domains including chromatographic column, adsorption-based membranes and heterogeneous catalysis, where hydrolytic stability constituted a challenging issue. In spite of its benefits, trimethylsilylation of graphene oxide has been only sporadically investigated and this underlooked chemistry needs to be accurately addressed for further tailoring the surface properties of graphene materials. With this aim, we herein screened a set of commercially available trimethylsilyl reagents for end-cuping the surface of graphene oxide. Surprisingly, meticulous investigations show that these reagents behave primarily as nucleophiles and induce oxirane opening, with a diverging pattern depending on the functional group linked to trimethylsilyl fragments. Specifically: i) trimethylsilylchloride and trimethylsilyltriflate are not suitable because of the substantial side products formed under acidic conditions; ii) trimethylsilylimidazolium reacts rather through its imidazolium group with the simultaneous elimination of trimethylsilyl groups; iii) bis-silylated reagents like hexamethyldisilazane and N,O-bis-trimethylsilyl-trifluoroacetamide enable anchoring at least one functional arm while liberating the second trimethylsilyl moity. The introduced functionalities enhance the dispersion of the newly prepared graphenes in liquid medium, thereby broadening the library of solvents suitable for their handling and offering more possibilities for the ink processability. Regardless of the starting reagent, the resulting functionalisation do not compromise the anchoring ability of the graphene surface as illustrated by supporting InP/ZnS semiconductor nanocrystals. In the whole, these serendipitous findings challenge the conventional wisdom about the reactivity of trimethylsilyl reagents that was primarly associated to surface hydrophobisation, opening indeed new possibilities for graphene functionalisation and further use in materials science