Advanced (1)H, (13)C, and (31)P solution and solid-state NMR studies combined with IR spectroscopy were used to probe, at the molecular scale, the composition and the surface chemistry of indium phosphide (InP) quantum dots (QDs) prepared via a non-coordinating solvent strategy. This nanomaterial can be described as a core-multishell object: an InP core, with a zinc blende bulk structure, is surrounded first by a partially oxidized surface shell, which is itself surrounded by an organic coating. This organic passivating layer is composed, in the first coordination sphere, of tightly bound palmitate ligands which display two different bonding modes. A second coordination sphere includes an unexpected dialkyl ketone and residual long-chain non-coordinating solvents (ODE and its isomers) which interact through weak intermolecular bonds with the alkyl chains of the carboxylate ligands. We show that this ketone is formed during the synthesis process via a decarboxylative coupling route and provides oxidative conditions which are responsible for the oxidation of the InP core surface. This phenomenon has a significant impact on the photoluminescence properties of the as-synthesized QDs and probably accounts for the failure of further growth of the InP core.

Abstract:The influence of a transverse static magnetic field on the magnetic hyperthermia properties is studied on a system of large-losses ferromagnetic FeCo nanoparticles. The simultaneous measurement of the high-frequency hysteresis loops and of the temperature rise provides an interesting insight into the losses and heating mechanisms. A static magnetic field of only 40 mT is enough to cancel the heating properties of the nanoparticles, a result reproduced using numerical simulations of hysteresis loops. These results cast doubt on the possibility to perform someday magnetic hyperthermia inside a magnetic resonance imaging setup. Main Text:Magnetic hyperthermia (MH) is a promising cancer treatment technique based on the fact that magnetic nanoparticles (MNPs) placed in an alternating magnetic field release locally heat [1,2,3]. Its efficiency in combination with radiotherapy has been recently demonstrated in the treatment of glioblastome multiforme [4].On the long term, performing magnetic hyperthermia in a magnetic resonance imaging (MRI) setup could have several advantages: i) The production of the magnetic field for MH could be produced by the same hardware as for the MRI. ii) The measurement of the local temperature during hyperthermia treatment using MRI thermometry could allow for a better control of the treatment, by avoiding overheating effect in the safe zones. iii) MRI can quantify of the local concentration of nanoparticles trapped inside the tumor, which is essential to define the treatment parameters.However, the presence of a static magnetic field in MRI set-ups should decrease the specific absorption rate (SAR) of the MNPs, as pointed out by a few theoretical works [5,6,7,8]. This explains why the development of a combined system should probably be based on a lowfield MRI setup working a static field of 0.1 or 0.2 T only [5]. So far, no experimental study of the influence of a static magnetic field on the MH properties of MNPs has been reported. In the present article, we report such an investigation for a model system of ferromagnetic FeCo nanoparticles. In a first study, we demonstrated that these NPs display large losses and a behavior typical of the Stoner-Wohlfarth regime [9]. To go deeply into the mechanisms involved, the influence of the static magnetic field on MH properties is studied by combining temperature measurements and high-frequency hysteresis loop measurements. Our results, which are consistent with numerical calculations of the hysteresis loops, show that a small magnetic field is sufficient to cancel the heating properties of the MNPs.

[formula: see text] A chiral pyridine-bis(oxazoline) ligand, functionalized with a vinyl group in the pyridine ring, can be polymerized with styrene and divinylbenzene to obtain supported chiral ligands. As proof of the usefulness of this supported ligands, the corresponding ruthenium complexes are catalysts for the cyclopropanation reaction of styrene with ethyl diazoacetate with up to 85% ee.

Supported catalysts having pybox chiral moieties were prepared as macroporous monolithic miniflow systems. These catalysts are based on styrene-divinylbenzene polymeric backbones having different compositions and pybox chiral moieties. Their corresponding ruthenium complexes were tested for the continuous flow cyclopropanation reaction between styrene and ethyldiazoacetate (EDA) under conventional conditions and in supercritical carbon dioxide (scCO2). Ru-Pybox monolithic miniflow reactors not only provided a highly efficient and robust heterogeneous chiral catalyst but also allowed us to develop more environmental reaction conditions without sacrificing the global efficiency of the process.

Monolithic polymers functionalised with BOX-Cu moieties can be applied for the cyclopropanation reaction under batch and flow conditions using either conventional or supercritical solvents.

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A novel method has been developed for the silica coating of iron nanoparticles while preserving the magnetic properties.