On the possibility of magneto-structural correlations: detailed studies of di-nickel carboxylate complexes

A series of water-bridged dinickel complexes of the general formula [Ni<sub>2</sub>(μ<sub>2</sub>-OH<sub>2</sub>)(μ2- O<sub>2</sub>C<sup>t</sup>Bu)<sub>2</sub>(O<sub>2</sub>C<sup>t</sup>Bu)2(L)(L0)] (L = HO<sub>2</sub>C<sup>t</sup>Bu, L0 = HO<sub>2</sub>C<sup>t</sup>Bu (1), pyridine (2), 3-methylpyridine (4); L = L0 = pyridine (3), 3-methylpyridine (5)) has been synthesized and structurally characterized by X-ray crystallography. The magnetic properties have been probed by magnetometry and EPR spectroscopy, and detailed measurements show that the axial zero-field splitting, D, of the nickel(ii) ions is on the same order as the isotropic exchange interaction, J, between the nickel sites. The isotropic exchange interaction can be related to the angle between the nickel centers and the bridging water molecule, while the magnitude of D can be related to the coordination sphere at the nickel sites

Towards robust alkane oxidation catalysts: electronic variations in non-heme iron(II) complexes and their effect in catalytic alkane oxidation

A series of non-heme iron(II) bis(triflate) complexes containing linear and tripodal tetradentate ligands has been prepared. Electron withdrawing and electron donating substituents in the para position of the pyridine ligands as well as the effect of pyrazine versus pyridine and sulfur or oxygen donors instead of nitrogen donors have been investigated. The electronic effects induced by these substituents influence the strength of the ligand field. UV-vis spectroscopy and magnetic susceptibility studies have been used to quantify these effects and VT 1H and 19F NMR spectroscopy as well as X-ray diffraction have been used to elucidate structural and geometrical aspects of these complexes. The catalytic properties of the iron(II) complexes as catalysts for the oxidation of cyclohexane with hydrogen peroxide have been evaluated. In the strongly oxidising environment required to oxidise alkanes, catalyst stability determines the overall catalytic efficiency of a given catalyst, which can be related to the ligand field strength and the basicity of the ligand and its propensity to undergo oxidation

Anderson-type Polyoxometalates Functionalized by a New Class of Organic Photochromic Molecule

International audienc

Synthesis and characterization of a new hybrid polyoxometalate for photopolymerization process

International audienc

Synthesis and characterization of a new hybrid polyoxometalate for photopolymerization process

International audienc

Heterogenisation of polyoxometalates and other metal-based complexes in metal–organic frameworks: from synthesis to characterisation and applications in catalysis

International audienceThese last years have seen a huge growing interest in the heterogenisation of molecular catalysts since it allows combining the advantages of homogeneous and heterogeneous catalysis. Besides bringing recyclability, the immobilisation of the catalyst may increase its stability while allowing tuning its selectivity. In this respect, Metal-Organic Frameworks (MOFs) attract an evergrowing interest as a platform for their confinement within their pores or channels. In this review, Cat@MOF composites whereby molecular catalysts (Cats) are immobilised in MOFs through non-covalent interactions with their host, are reviewed thoroughly. Polyoxometalates (POMs) and other metal-based complexes as immobilised molecular species are covered. In the first part, the different synthetic methods and analytical tools are described. A critical analysis of the various physico-chemical methods available to characterise the Cat@MOF composites is provided-a particular attention being paid toward their pertinence for the investigation of the content, the position and the stability of the catalyst within the MOF. Besides, focus is made on non-conventional techniques such as Pair Distribution Function (PDF) and a section is dedicated to the contribution of DFT calculations. In the second part, the applications of these materials in the fields of catalysis, including oxidation and reduction reactions, acid-base catalysis, photo-and electrocatalysis are detailed

Gold/Polyoxometalate core/shell nanoparticles for combined chemotherapy/photothermal cancer therapy

International audienc

Synthesis and Characterization of Polyoxometalates/Antibiotics/Gold Nanoparticles Hybrid Materials for Antibacterial Applications

International audienc