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International audience; Microporous ceria thin films having nanocrystallites network were synthesized by evaporation-induced self-assemblyprocess, using P123 amphiphilic copolymer as structure-directing agent. The impact of key experimental parameters,i.e., the sol ageing, the relative humidity (RH), the thermal treatment, on the thin layer elaboration were investigated.The results show that the organization of the nanoparticles is possible for a sol ageing time lower than 16 days and thatthe size of the mesophase within the thin layer increases with the relative humidity fixed during the film deposition.Finally, an increase of the thermal treatment temperature from 300 to 1000 °C leads to the formation of fluorite-likedioxide material coupled with a loss of nanocrystallites organization and porosity due to the increase of the size of thecrystallites. This loss of nanocrystallites organization is more drastic in the direction perpendicular to the surface andless pronounced along the surface. Thus, a compromise between the crystallization and the preservation of the porosityneeds to be found.

International audience; The preparation and structural characterization of an original Th peroxo sulfate dihydrate, crystallizing at room temperature in the form of stable 1D polymeric microfibres is described. A combination of laboratory and synchrotron techniques allowed solution of the structure of the Th(O2)(SO4)(H2O)2 compound, which crystallizes in a new structure type in the space group Pna21 of the orthorhombic crystal system. Particularly, the peroxide ligand coordinates to the Th cations in an unusual μ3‐η2:η2:η2 bridging mode, forming an infinite 1D chain decorated with sulfato ligands exhibiting simultaneously monodentate and bidentate coordination modes.

Tuning the affinity of a medium for a given metallic cation with the sole modification of weak interactions is a challenge for molecular recognition. Solvent extraction is a key technique employed in the recovery and purification of valuable metals, and it is facing an increased complexity of metal fluxes to deal with. The selectivity of such processes generally relies on the use of specific ligands, designed after their coordination chemistry. In the present study, we illustrate the possibility to employ the sole control of weak interactions to achieve the selective extraction of Pd(II) over Nd(III) : the control over selectivity is obtained by tuning the self-assembly of the organic phase. A model is proposed, after detailed experimental analysis of molecular (XRD, NMR) and supra-molecular (SAXS) features of the organic phases. We thus demonstrate that Pd(II) extraction is driven by metal coordination, whereas Nd(III) extraction requires aggregation of the extractant in addition to metal coordination. These results are of general interest for the applications which rely on the stabilization of metals in organic phases.

International audience; Actinide research at the nanoscale is gaining fundamental interest due to environmental and industrial issues. The knowledge of the local structure and speciation of actinide nanoparticles, which possibly exhibit specific physico-chemical properties in comparison to bulk materials, would help in a better and reliable description of their behaviour and reactivity. Herein, the synthesis and relevant characterization of PuO2 and ThO2 nanoparticles displayed as dispersed colloids, nanopowders or nanostructured oxide powders, allow to establish a clear relationship between the size of the nanocrystals composing these oxides and their corresponding An(IV) local structure investigated by EXAFS spectroscopy. Particularly, the probed An(IV) first oxygen shell evidences an analogous behaviour for both Pu and Th oxides. This observation suggests that the often observed and controversial splitting of the Pu-O shell on the Fourier transformed EXAFS signal of PuO2 samples is attributed to a local structural disorder driven by a nanoparticle surface effect rather than to the presence of PuO2+x species.

This manuscript describes the original structuring of Mg materials under ultrasound irradiation in mild conditions. Golf ball like extended structures can be prepared in dilute oxalic solutions at 20 °C under high frequency ultrasound (200 kHz). An original approach carried out through iterative 3D reconstruction of sonicated surfaces is used to describe surface evolutions and characterize the formed microstructures. A combination of SEM, ICP-AES, contact-angle measurements, and 3D image analyses allows to characterize the roughness and mass loss evolutions, and investigate the mechanism of formation for such architectures. A screening of the sonication experiments clearly points out an ultrasound frequency dependency for the effects generated at the surface. 200 kHz sonication in 0.01 M oxalic acid provides an unprecedented manufacturing of Mg samples which result from a controlled and localized dissolution of the material and characterized by a strong wetting surface with a roughness of 170 nm. The additional formation of newly formed secondary phases appearing with surface dissolution progress is also deciphered. More generally, the ultrasonic procedure used to prepare these engineered surfaces opens new alternatives for the nano- and micro-structuring of metallic materials which may exhibit advanced physical and chemical properties of potential interest for a large community.

International audience; In the last decade organic–inorganic hybrid materials have become essential in materials science as they combine properties of both building blocks. Nowadays the main routes for their synthesis involve electrostatic coupling, covalent grafting, and/or solvent effects. In this field, polyoxometalates (POMs) have emerged as interesting inorganic functional building blocks due to their outstanding properties. In the present work the well‐known α‐Keggin polyoxometalate, α‐PW12O403− (PW), is shown to form hybrid crystalline materials with industrial (neutral) polyethylene glycol oligomers (PEG) under mild conditions, that is, in aqueous medium and at room temperature. The formation of these materials originates from the spontaneous self‐assembly of PW with EOx, (EO=ethylene oxide) with at least four EO units (x>4). The PW–PEG nanoassemblies, made of a POM surrounded by about two PEG oligomers, are stabilized by electrostatic repulsions between the negatively charged PW anions. Addition of NaCl, aimed at screening the inter‐nanoassembly repulsions, induces aggregation and formation of hybrid crystalline materials. Single‐crystal analysis showed a high selectivity of PW towards EO5–EO6 oligomers from PEG200, which is made of a mixture of EO3–8. Therefore, a general “soft” route to produce POM–organic composites is proposed here through the control of electrostatic repulsions between spontaneously formed nanoassemblies in water. However, this rational design of new POM hybrid (crystalline) materials with hydrophilic blocks, using such a simple mixing procedure of the components, requires a deep understanding of the molecular interactions.

The solubilisation of polar and polyphenol antioxidant in vegetable oils was studied. It was shown that the use of a polyglyceryl-3-diisostearate (PG3DS), a bio-sourced emulsifier well known in cosmetics, increases the yield of solubilisation thanks to some aggregation properties analysed using x-ray scattering technique. We show indeed that PG3DS forms reverse aggregates with a critical concentration that depends on the oil polarity. PG3DS reverse aggregates are elongated with a polar core and cannot be really swollen by addition of water. This supramolecular organisation allows however an efficient solubilisation of polar antioxidants in vegetable oils.

A series of bidentate ligands associating an iminophosphorane and a phenoxide were synthesized and coordinated to nickel(II), leading initially to bimetallic KNi adducts. Replacement of the potassium by another metal allowed the isolation and characterization of bimetallic LiNi and AlNi complexes, while addition of one equivalent of triphenylphosphine gave access to monometallic complexes. The same type of complex was obtained with the coordination of a tridentate ligand incorporating a supplementary amine donor. These paramagnetic complexes were characterized by elemental analysis, and some of them by X-ray diffraction, evidencing a tetrahedral nickel center. They were shown to efficiently catalyze the oligomerization of ethylene in the presence of Et2AlCl (Al/Ni = 22.5) with TOF up to 72 000 mol(C2H4)/mol(Ni)/h, giving selectively butene (more than 97%) with at best 93% of 1-C4.

The oxidation of a Ni(II) complex bearing a tetradentate phosphasalen ligand, which differs from salen by the presence of an iminophosphorane (PN) in place of an imine unit, was easily achieved by addition of a silver salt. The site of this oxidation was investigated with a combination of techniques (NMR, EPR, UV/Vis spectroscopy, X-ray diffraction, magnetic measurements) as well as DFT calculations. All data are in agreement with a high-valent Ni(III) center concentrating the spin density. This markedly differs from precedents in the salen series for which oxidation on the metal was only observed at low temperature or in the presence of additional ligands or anions. Therefore, thanks to the good electron-donating properties of the phosphasalen ligand, [Ni(Psalen)](+) represents a rare example of a tetracoordinated high-valent nickel complex in presence of a phenoxide ligand.

We report the synthesis of a unique class of luminescent heterotrinuclear complexes of the general formulas [Pt(terpy)\Cp*Ir-p-(?4-C6H4Se2)\Pt(terpy)][X]4 (X = OTf, 3a; PF6, 3b; BF4, 3c; ClO4, 3d; BPh4, 3e). In these coordination assemblies two Pt(terpy) moieties are held by a stable ?4-diseleno-p-benzoquinone complex [Cp*Ir-p-(?4-C6H4Se2)]. The molecular structures of solvates of 3a and 3b were ascertained by single-crystal X-ray diffraction study and confirmed the formation of the target molecules. The solid-state packing of two of these complexes confirms the presence of π?π and Pt···Pt interactions among individual units providing a 1D supramolecular chain for 3a, while a dimer species is obtained for 3b, illustrating the effect of the counterion on directing the crystal packing of the individual molecules. All compounds show phosphorescence in the red region (685?705 nm) in fluid solution and in the solid state at room temperature, unlike the analogous compound Pt(terpy)\Cp*Ir-p-(?4-C6H4S2)\Pt(terpy)][CF3SO3]4 obtained with a dithiobenzoquinone organometallic linker, which is only luminescent at low temperature.

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International audience; Ultrasonically assisted hydrolytic precipitation of U(VI) in the presence of mesoporous alumina followed by thermal treatment of a solid precursor enabled the formation of crystallized uranyl aluminate (URAL) nanoparticles (NPs) dispersed in the alumina matrix. The effect of U(VI) concentration and calcination temperature on the yield of URAL NPs was studied using XRD, XAFS and HRTEM techniques. At 800 °C, URAL NPs (d ≈ 5 nm) are formed only for a low uranium loading of about 5 wt% whereas for a higher content of uranium, larger U3O8 NPs (d ≈ 20 nm) were identified as the principal uranium species. At 500 °C, URAL NPs are formed even for 25 wt% of uranium. The U LIII edge EXAFS spectra pointed out that uranyl cations in URAL are coordinated by bidentate aluminate groups. Presumably URAL is formed during the heating of the 2UO3·NH3·2H2O/AlO(OH) precursor. However, high temperature and higher content of uranium promote transformation of URAL to more thermodynamically stable U3O8. This process is accompanied by the growth of uranium NPs via the Ostwald ripening mechanism.

International audience; A series of highly active yttrium phosphasalen initiators for the heteroselective ring-opening polymerization of rac-lactide are reported. The initiators are yttrium alkoxide complexes ligated by iminophosphorane analogues of the popular "salen" ligand, termed "phosphasalens". A series of novel phosphasalens have been synthesized, with varying substituents on the phenoxide rings and ethylene, propylene, rac-cyclohexylene, R,R-cyclohexylene, phenylene, and 2,2-dimethylpropylene groups linking the iminophosphorane moieties. Changing the substituents on the phosphasalen ligands results in changes to the rates of polymerization (kobs) and to the PLA heterotacticity (Ps = 0.87). Generally, the initiators have high rates, excellent polymerization control, and a tolerance to low loadings.

International audience; The new 1,1′-diphosphaplumbocenes Pb(Dtp)2(Dtp = 2,5-di-tert-butyl-3,4-dimethylphospholyl) and Pb(Dsp)2(Dsp = 2,5-ditrimethylsilyl-3,4-dimethylphospholyl) have beensynthesized and characterized by multinuclear NMR spectroscopy.207Pb NMR spectra of both complexes, as well as for theknown complex Pb(Htp)2 (Htp = 2,5-di-tert-butylphospholyl),show that the phospholyl ligands lead to an important downfieldshift compared with that of cyclopentadienyl based plumbocenes.X-ray diffraction studies of the Pb(Dtp)2 complex revealed astructure with two slightly bent η5-bound ligands. This complexwas employed in the oxidative ligand transfer reaction with bulkydivalent thulium complexes. In the case of Tm(Dtp)2, the firstexample of a monomeric trivalent tris(phospholyl)lanthanidecomplex Tm(Dtp)3 was obtained. X-ray diffraction studies andlow-temperature 1H NMR studies show the η1 coordination mode of the third Dtp ligand. In contrast, oxidation of Tm(Cpttt)2(Cpttt is for tris-tert-butylcyclopentadienyl) led presumably to the formation of the ion pair complex [Tm(Cpttt)2][Dtp], in whichno interaction between the free Dtp ligand and Tm was observed, as shown by variable temperature 1H and 31P NMR studies.The new trivalent complexes could be reduced back to the original divalent complexes with potassium graphite.

The reactivity of both the monoanionic and dianionic forms of bis(diphenylthiophosphinoyl)methane (2– and 22–) as well as the dianion of tetraisopropyl methylenediphosphonate(32–) was investigated towards the same CoII precursor CoCl2. Monoanion 2– coordination yields a homoleptic zwitterionic CoII complex. However, both dianions (22– and 32–) give the same overall structure with a square Co2C2 core. Structures of all of the complexes have been confirmed by full NMR spectroscopic analysis and X-ray diffraction. Furthermore, DFT calculations have been carried out to rationalize the stability of such species.

International audience; (Chemical Equation Presented) Two approaches to vinigrol starting from the advanced tricyclic core 7 have been explored using as key intermediates epoxide 12 and diol 17. The preparation of the properly functionalized epoxide 12 has been achieved in a straightforward fashion. However, all attempts to prepare tertiary alcohol 14 by reductive opening of 12 failed. In alternative exploratory efforts to achieve the same goal, allylic alcohols 16 and 29 were prepared by regioselective dehydration of diol 17. Whereas endo-isomer 16 was found to be reluctant to undergo catalytic hydrogenation, the exo counterpart 29 led to the undesired isomer affording after hydrolysis epi-C-8-dihydrovinigrol 32. © 2009 American Chemical Society.

International audience; Chromium(III) complexes bearing R'N(CH2PR2)2 (PCNCP) ligands were prepared. Upon activation with methylaluminoxane, these complexes proved to be effective in the selective tri- and tetramerization of ethylene. The formation of either 1-hexene or 1-octene was found to be highly dependent on the steric bulk of the substituents R on the phosphine moieties. This observation was rationalized using density functional theory calculations on selected steps of the metallacyclic mechanism of the ethylene oligomerization reaction.

Using a one-pot four-step reaction a readily available phospholide was converted efficiently to a 2-carboxyphosphole. This compound can be used as a building block for the synthesis of phosphole-containing peptides, where the phosphole can serve as a coordination site for late transition metals and may affect the secondary structure of the peptide.

This work highlights the relative importance between structural issues, longer range interactions and solvent effects for a series of ruthenium compounds on their electrochemical and photochemical properties. To study these effects, eight complexes of general formula [Ru(bpy)2(L)]2+ have been synthesized and characterized, where L represents substituted phenyl-imidazophenanthrolines (pip), dipyridophenazines (dppz) and pyrazinophenanthrolines (pzp). This experimental work supported by an important theoretical investigation has pointed out that the electrochemical and the photo-physical behavior of these types of molecular systems depends mainly of the close environment around the photosensitizer. A relation between the ditopic ligand structure (aromatic central part and/or the distal substituents) and the absorption properties have been observed, along with the lower reduction potential of dipyridophenazine and pyrazinophenanthroline moieties. This study points out the influence of the nature of the distal substituents, as well as the significant impact of the solvent nature and the interaction with water molecules, on the photo-physical properties of these ruthenium compounds.

A series of dinuclear [(bpy)2Ru(L)Ru(bpy)2]4+ and mononuclear ruthenium(II) complexes [(bpy)2Ru(L)]2+ where bpy is 2,2′-bipyridine and L represents 2,6-di(1H-imidazo[4,5-f][1,10]phenanthrolin-2-yl)aryl ligands (DIP) were synthetized and characterized. An original pathway is proposed to obtain mono and hetero bi- and polymetallic Ru complexes and the relation between the molecular structure, the photophysical and electrochemical properties of the single Ru complexes is analysed. The investigated aryl cores are benzene, pyridine and 4-tert-butyl phenol. This work is focused on the effect of the aromatic moiety on the photoinduced charge transfer in the bimetallic compounds and the results are compared with the monometallic analogues. The absence of effect on the UV-visible absorption spectra and on the redox behavior upon varying the nature of the aryl moiety show that the two metallic centres in [(bpy)2Ru(L)Ru(bpy)2]4+ complexes are independent. However, luminescence measurements coupled with DFT calculations highlight a different photophysical behaviour between mono and dinuclear compounds incorporating the benzene core. Theoretical DFT and TD-DFT modelling was used to support the studied physico-chemical properties of these molecular systems.

International audience; The synthesis of the bulky divalent(polyphenylcyclopentadienyl)lanthanoid sandwich complexes[Ln(C5Ph5)2] (Ln = Sm, Eu) and [Ln(C5Ph4H)2(solv)] (Ln =Sm, solv = thf; Ln = Eu, solv = dme)], from redoxtransmetalation/protolysis (RTP) reactions, has beenachieved. An analogous reaction with Yb afforded thesolvent-separated ion pair [Yb(dme)4][C5Ph4H]2. In addition,rare divalent samarium halide complexes [Sm(C5Ph5)(μ-Br)(thf)2]2 and [Sm(C5Ph4H)I(thf)3], were also prepared,either by RTP or ligand rearrangement. X-ray studies showedthat the [Ln(C5Ph5)2] complexes adopt highly symmetrical sandwich structures, whereas the [Ln(C5Ph4H)2(solv)] complexeshave open sandwich structures. The unexpected, but limited, solubility of the [Ln(C5Ph5)2] complexes allowed for variabletemperatureNMR spectra of [Sm(C5Ph5)2] to be obtained. Detailed 1D and 2D NMR studies were conducted on[Sm(C5Ph4H)2(thf)] to ascertain its structure in donor and nondonor solvents. During the course of these studies, the mixedtetraarylcyclopentadienyl sandwich complex [Sm{C5(2,5-Ph)2(3,4-p-tol2)H}2(thf)] was also prepared in order to fully assign thespectrum of [Sm(C5Ph4H)2(thf)]. The europium sandwich complexes [Eu(C5Ph5)2] and [Eu(C5Ph4H)2(dme)] exhibitremarkable luminescence properties with high quantum yields (45% and 41%, respectively) coupled with long emission lifetimes(approximately 800 and 1300 ns, respectively) in toluene.

A promising strategy to design highly active catalysts is to use multicomponent catalysts including active metals (such as platinoids) and organosilica as a substrate. In this article, we develop stable OrganoSilica Sandwiches (OSS) consisting of sandwiched metallic layers between organosilica layers. The formation of such a sandwich-like organosilica@platinoid@organosilica material was obtained from bis-silica-alkylammonium carbamate dimers, acting as a template for the immobilization of platinoid salt complexes or metallic nanoparticles in the interlayer space after a reduction treatment. The layered templates and the sandwich structures were investigated by small angle X-ray scattering, coupled thermogravimetric analysis and mass spectrometry, and Raman spectroscopy. It was demonstrated that the meso-structure of the initial template material is not affected by the chemical steps involved in the synthesis of the material and does not depend on the incorporated metal.

The functionalization of single-walled carbon nanotubes was performed with four organic molecules. A careful study involving thermo-gravimetric analysis and Raman spectroscopy allowed us to quantify the grafting rate of each molecule, and to evidence a preferential grafting of metallic or semiconducting tube depending on the molecule under consideration. In order to understand the origin of this selectivity, we performed DFT calculations of the electronic structure of the molecules, and compared it to the electron density of states of carbon nanotubes. This approach allowed us to propose a paradigm for explaining the grafting affinity of organic molecules towards metallic or semiconducting nanotubes, and for estimating the grafting efficiency. It could further be used in order to predict the selectivity of any molecule containing a double or triple carbon bond towards metallic or semiconducting carbon nanotubes.

International audience; A family of five homobimetallic complexes with magnetically-active trivalent lanthanides of the second half of the series with general formula [{Ln(tta)3}2(μ-bpm)] (Ln = Gd, Tb, Dy, Ho, Er, tta = 2-thenoyltrifluoroacetonato, bpm = 2,2′-bipyrimidine) has been structurally characterized by X-ray diffraction and the magnetic properties of these complexes are reported. The two lanthanide ions are coordinated to the bridging bpm ligand which connects the two metallic centers. The magnetic behavior of these complexes has been investigated. It revealed that a weak antiferromagnetic coupling is observed with the TbIII, DyIII, HoIII, and ErIII ions while a very weak ferromagnetic exchange between the two GdIII ions was observed.

International audience; Early transition metal nucleophilic carbene complexes have been used as stoichiometric carbene transfer agents in a transmetalation process.

International audience; Highly active yttrium phosphasalen initiators for the stereocontrolled ring-opening polymerization of rac-lactide are reported. The initiators are coordinated by a new class of ancillary ligand: an iminophosphorane derivative of the popular "salen" ligand, termed "phosphasalen". Changing the phosphasalen structure enables access to high iso-selectivities (Pi = 0.84) or hetero-selectivities (Ps = 0.87). The initiators also show very high rates, excellent polymerization control, and tolerance to low loadings; furthermore, no chiral auxiliaries/ligands are needed for the stereocontrol. The combination of such high rates with high iso-selectivities is very unusual.

International audience; A new unsymmetrical geminal dianion that contained both a phosphine oxide moiety and a phosphine sulfide moiety has been synthesized. Its reactivity towards Ru(II) was explored, which led to the formation of a highly reactive carbene complex that evolved at room temperature to yield a kinetic orthometalated Ru(II) complex through C-H activation of the phenyl group of the phosphine oxide moiety. This insertion was found to be thermally reversible and a second C-H insertion occurred at a phenyl group of the phosphine sulfide moiety to form the thermodynamic orthometalated Ru(II) complex in a diastereospecific manner. DFT calculations fully rationalized the experimental findings in terms of the relative energies of the kinetic and thermodynamic products and allowed the mechanism of this process to be fully understood.

International audience; Preparation and characterization of three yttrium alkoxide complexes with new phosphasalen ligands are reported. The phosphasalens are analogues of the well-known salen ligands but with iminophosphorane donors replacing the imine function- ality. The three yttrium alkoxide complexes show mono- and dinuclear structures in the solid state, depending on the substituents on the ligand. The new ligands and complexes are characterized using multinuclear NMR spectr oscopy, mass spectrometry, elemental analysis, and single-crystal X-ray diffraction experiments. The complexes are all rapid initiators for lactide polymerization; they show excellent polymerization control on addition of exogeneous alcohol. The mononuclear complex shows extremely rapid rates and a high degree of stereocontrol in rac-lactide polymerization, yielding heterotactic PLA (Psof 0.9). The phosphasalens are, therefore, excellent ligands for lactide ring-opening polymerization catalysis showing superior rates and stereocontrol versus salen ligands, which may be related to their excellent donating ability and the high degrees of steric protection they can confer.

International audience; A copper iodide cluster bearing reactive silanol groups exhibits thermochromic luminescence properties sensitive to its chemical environment and is thus a suitable building block for the synthesis of optically active materials.

International audience; A homobimetallic complex, [{Sm(tta)3(MeOH)}2(μ-bpm)]*1 bpm (tta = 2-thenoyltrifluoroacetonato, bpm = 2,2′-bipyrimidine) has been synthesized and structurally characterized by single-crystal X-ray diffraction. Magnetic measurements (between 5 and 295 K) show that the two metal centers bridged by the bpm connector are magnetically almost isolated. The SmIII emission is observed upon excitation in a wide range of wavelengths going from the UV to the visible (250-500 nm).

International audience; A double ring-expansion methodology allows the stepwise synthesis of tri- and tetra-phosphaporhyrinogens. Structural and calculational methods reveal extended delocalisation about their phospholide centres.

International audience; Three copper(I) iodide clusters coordinated by different phosphine ligands formulated [Cu(4)I(4)(PPh(3))(4)] (1), [Cu(4)I(4)(Pcpent(3))(4)] (2), and [Cu(4)I(4)(PPh(2)Pr)(4)] (3) (PPh(3) = triphenylphosphine, Pcpent(3) = tricyclopentylphosphine, and PPh(2)Pr = diphenylpropylphosphine) have been synthesized and characterized by (1)H and (31)P NMR, elemental analysis and single crystal X-ray diffraction analysis. They crystallize in different space groups, namely, monoclinic P21/c, cubic Pa3̅, and tetragonal I4̅2m for 1, 2, and 3, respectively. The photoluminescence properties of clusters 1 and 3 show reversible luminescence thermochromism with two highly intense emission bands whose intensities are temperature dependent. In accordance to Density Functional Theory (DFT) calculations, these two emission bands have been attributed to two different transitions, a cluster centered (CC) one and a mixed XMCT/XLCT one. Cluster 2 does not exhibit luminescence variation in temperature because of the lack of the latter transition. The absorption spectra of the three clusters have been also rationalized by time dependent DFT (TDDFT) calculations. A simplified model is suggested to represent the luminescence thermochromism attributed to the two different excited states in thermal equilibrium. In contrast with the pyridine derivatives, similar excitation profiles and low activation energy for these phosphine-based clusters reflect high coupling of the two emissive states. The effect of the Cu-Cu interactions on the emission properties of these clusters is also discussed. Especially, cluster 3 with long Cu-Cu contacts exhibits a controlled thermochromic luminescence which is to our knowledge, unknown for this family of copper iodide clusters. These phosphine-based clusters appear particularly interesting for the synthesis of original emissive materials.

A phosphorus analog of salen ligands featuring iminophosphorane functionalities in place of the imine groups was synthesised in 2 steps from o-diphenylphosphinophenol via the preparation of the corresponding bis-aminophosphonium salt. This novel tetradentate ligand (1), which we named phosphasalen, was coordinated to Pd(II) and Ni(II) metal centres affording complexes 6 and 7 respectively, which were characterised by multinuclear NMR, elemental and X-ray diffraction analyses. Both neutral complexes adopt a nearly square-planar geometry around the metal with coordination of all iminophosphorane and phenolate moieties. The electronic properties of these new complexes were investigated by cyclic voltammetry and comparison with known salens was made when possible. Moreover, the particular behaviour of the phosphasalen nickel complex 7 was further investigated through magnetic moment measurements and a DFT study.

Two different Smiles rearrangements can be combined to afford a multicomponent formation of isoquinolinones and isoindolinones from nitro methyl salicylate. After a Ugi−Smiles four-component coupling, the base-triggered cyclization of the resulting adduct is followed by a ring contraction via a Truce−Smiles rearrangement.

International audience; The mechanochromic and thermochromic luminescence properties of a molecular copper(I) iodide cluster formulated [Cu4I4(PPh2(CH2CH═CH2))4] are reported. Upon mechanical grinding in a mortar, its solid-state emission properties are drastically modified as well as its thermochromic behavior. This reversible phenomenon has been attributed to distortions in the crystal packing leading to modifications of the intermolecular interactions and thus of the [Cu4I4] cluster core geometry. Notably, modification of the Cu−Cu interactions seems to be involved in this phenomenon directly affecting the emissive properties of the cluster.

Protonation of a bidentate xantphos-phosphole ligand by HBF(4) affords only one enantiomer of a cyclic phospholium dihydropholene structure. DFT calculations allowed us to establish that protonation initially takes place at the phosphorus atom of the phosphole moiety to afford a transient P-H phospholium salt, which in turn protonates the C=C double bond of the second phosphole unit.

International audience; A study was conducted to demonstrate efficient cycloisomerization of a series of 1,9- and 1,10-diynes into medium sized cycloalkynes by a gold-catalyzed alkyne-alkyne coupling. The reaction was performed using 4 mol% of gold complex in CD2Cl2 at room temperature and was monitored by using 1H NMR spectroscopy. The reaction of analogous diyne substrate was more rapid and a complete conversion was observed after 40 hours at room temperature. The cycloalkyne was isolated as a solid in 95% yield from which single crystals suitable for X-ray crystal structure determination was obtained. A rapid screening of catalysts and experimental conditions was undertaken to optimize the formation of cycloalkyne. A mechanistic proposal was also introduced for the cycloisomerization of diynes into cycloalkynes on the basis of the experimental observations.

The bis-2,5-diphenylphosphole xantphos ligand (XDPP) 1 reacts with the [AuCl(tht)] complex to afford the monocoordinated [Au(XDPP)Cl] 2 and the dicoordinated chelate species [Au(XDPP)Cl] 3. Addition of AgOTf on this mixture, at room temperature, affords the cationic [Au(XDPP)][OTf] complex 4 which was fully characterized. An X-ray crystal structure analysis confirms the bent structure of this 14 VE [ML(2)](+) complex. Reaction of 4 with HSiMe(2)Ph in tetrahydrofuran at -78 degrees C yields the dinuclear [(XDPP)Au-H-Au(XDPP)](+) cationic complex 5, in which the hydride bridges the two [Au(XDPP)](+) metal fragments. In 5, the Au-P bond lengths are different and the phosphorus atoms which are located nearly trans to the hydride ligand exhibit significantly shorter P-Au bond lengths. Reaction of 4 with DSiMe(2)Ph to form the [(XDPP)Au-D-Au(XDPP)](+) complex 6 allowed to unambiguously ascribe the chemical shift of the deuteride in (2)H NMR (delta = 7.0 ppm with a (2)J(DP) = 8.4 Hz. The electronic structure of the [(XDPP)Au-H-Au(XDPP)](+) complex was studied through density functional theory calculations. An orbital analysis is developed in which complex 5 is viewed as the combination of two 12 electrons fragments [Au(XDPP)](+) with H(-). This analysis reveals that the hydride interacts in a bonding way with the sigma MO between the two gold atoms and in an antibonding way with a combination of d orbitals at the metal centers. This simple description allows to rationalize the inequivalence of the two types of P-Au bonds in 5.

A series of mixed tetradentate ligands associating two iminophosphorane moieties with two phosphino, thiophosphino, or phosphine oxide groups (labelled 2, 3, and 4 respectively) have been prepared from the corresponding aminophosphonium derivatives. Their coordination to the iron dichloride metal fragment was achieved using the [FeCl(2)(THF)(1.5)] precursor leading to [(P(2)N(2))FeCl(2)] (5), [(S(2)N(2))FeCl(2)] (6), and [(O(2)N(2))FeCl(2)] (7). These complexes were shown to be paramagnetic. Moreover, those ligands can act as bi, tri or tetradentate, as evidenced by X-ray structure analysis of the complexes, depending on the nature of the pendant PY coordinating ligand (Y = lone pair, S, O). Indeed, while only one phosphorus atom is coordinated to iron in 5 (PNN coordination), no thiophosphine moiety is connected to Fe in 6 (NN coordination), whereas both phosphine oxide arms are linked to the metal in 7 (ONNO) coordination. For ligand 2, coordination reactions were also performed with a non-chlorinated iron precursor (either [Fe(CH(3)CN)(6)](BF(4))(2) or [Fe(H(2)O)(6)](BF(4))(2)) leading to complexes 8 and 9 depending on the reaction conditions. The different iron(II) complexes 5-9 were tested in catalytic transfer hydrogenation of acetophenone, and were found to be efficient for reactions carried out at 82 degrees C.

A potentially tetradentate ligand was synthesized by the addition of α-Li-picoline to the 2,6-bis(diphenylphosphine sulfide)-3,5-diphenylphosphinine (SPS) ligand. The corresponding Pd complex (3) was obtained by the reaction with [(COD)PdCl2]. An air-stable cationic Pd(II) complex (4) was obtained after abstraction of Cl− with silver salt. The role of the additional binding site in the stabilization of the cationic complex was explored using NMR spectroscopic and tandem ESI-MS studies combined with DFT calculations. Additionally the picoline moiety was used to tune the electronic properties of the cationic complex 7 to modify the activity in the Lewis acid-catalyzed allylation of aldehydes.

11 pages; Reactions of the rhombic [MnII 2MnIII 2(hmp)6]4+ complex in acetonitrile with simple carboxylate ligands yield (i) three new isolated [Mn4] complexes, namely [Mn4(hmp)6(CH3COO)2(H2O)2](ClO4)2·4H2O (1), [Mn4(hmp)6(CCl3COO)2(H2O)2](ClO4)2 (2) and [Mn4(hmp)6(C6H5COO)2(H2O)2](ClO4)2·4CH3CN· 2H2O (3) in the presence of either bulky carboxylate or of an excess of Mn(II) source; and (ii) two 1D arrangements of [Mn4] complexes connected through double syn–syn carboxylate bridges when using acetate and chloroacetate, namely {[Mn4(hmp)6(CH3COO)2](ClO4)2·H2O}n (4) and {[Mn4(hmp)6(ClCH2COO)2](ClO4)2·2H2O}n (5). The assembly of such building blocks can thus be controlled by an adequate choice of the bridging anion. As expected, the isolated [Mn4] complexes behave as Single-Molecule Magnets as shown by the study of their static and dynamic magnetic properties. Detailed magnetic studies both on polycrystalline samples and single crystals show that the chain compounds are isolated antiferromagnetic chains. The slow relaxation of their staggered magnetization has been studied thanks to finite-size effects induced by the intrinsic defects of the material

Gold(I)-catalyzed cycloisomerization of 1,7- and 1,8-enyne propargylic acetates afforded cyclopropyl derivatives containing seven- and eight-membered rings, respectively. This reaction was used for the synthesis of a new allocolchicinoid having a cyclopropane ring fused to the B seven-membered ring at the C6-C7 positions.

International audience; A cationic xanthene phosphole palladium allyl complex efficiently catalyzes the deallylation of allyl ethers into alcohols and the concomitant formation of allyl amines. Parallel experiments and DFT calculations show that acidic catalysis plays a significant role in promoting the cleavage of the C−O bond in a 16 VE complex featuring an allyl ether as η2-ligand.

International audience; The incorporation of copper iodide clusters in sol−gel silica has been investigated to prepare materials with original luminescent properties. The synthesis, structural characterizations, and optical properties of sol−gel films containing [Cu4I4L4] clusters, L = phosphine-based ligands, are reported. Clusters studied are [Cu4I4(PPh2(CH2)2Si(OCH2CH3)3)4] (C1), able to copolymerize with the silica matrix, and [Cu4I4(PPh2(CH2)2CH3)4] (C2) used as a reference for the characterizations. The luminescent films exhibit the optical properties of these clusters in accordance with XPS and NMR studies demonstrating their integrity in the gel matrix. The temperature dependence of light emission properties of clusters and films shows, for the first time for phosphine-based [Cu4X4L4] clusters, thermochromic luminescence with bright yellow luminescence at room temperature and purple emission at 77 K. As a result of weak Cu−Cu interactions, the two emissive states appear as highly coupled with a low energy barrier (2 kJ·mol−1), leading to a controlled thermochromism in a large temperature range.

The new highly electron deficient ferrocenyldiphosphines [Fe{η5-C5H4P(CF3)2}2] (dfmpf) and [Fe{η5-C5H4P(C2F5)2}2] (dfepf) were synthesized by reaction of [Fe{η5-C5H4P(OPh)2}2] with CnF2n+1SiMe3/CsF...

International audience; BC ring-systems of taxol with different or no protecting group for the C1,C2 diol moiety have been efficiently synthesized. The 8-membered B ring is formed by a ring-closing metathesis (RCM) between the C10 and C11 carbons. The influence of the 1,2-diol protecting group on the RCM reaction has been studied in details.

International audience; Two new xanthene-phosphole derivatives, 3 and 4, were synthesized through the nucleophilic substitution of the cyano group in 1-P-cyano-2,5-diphenylphosphole (1) and 1-P-cyano- 3,4- dimethylphosphole (2) by the 4,5-dilithium salt of 9,9'-dimethylxanthene. For this, a new synthetic procedure was developed, allowing the synthesis of the required 1-P-cyano-2,5-diphenylphosphole from the 1,2,5-triphenylphosphole. Both ligands (DPP-Xantphos 3 for the diphenyl derivative and DMP-Xantphos 4 for the dimethyl derivative) react with [Pd(allyl)Cl](2) to afford the corresponding cationic complexes 5Cl and 6Cl. Using AgOTf, stable triflate complexes 5OTf and 6OTf could be isolated. The chloride complexes, on the other hand, exhibit a limited stability in solution. The DPP-Xantphos derivative 5Cl eliminates allyl chloride to yield the dimeric palladium(0) complex 7 of general formula [Pd(3)](2), in which each palladium is coordinated to the two phosphorus atoms of the same ligand and to one double bond of one phosphole unit of the second ligand. Decomposition of complex 6Cl furnished a mixture of compounds featuring a dimeric trinuclear species of general formula [Pd-3(4)(2)Cl-2]. This complex was also synthesized directly. Reaction of the DMP-Xantphos ligand 4 with 1 equiv of [Pd(COD)Cl-2] and 2 equiv of [Pd(dba)(2)] afforded dimer 8, which features one 18-VE Pd-0 center and two Pd-Cl fragments, which are coordinated to the dienic system of the two phosphole ligands and connected through a single Pd-Pd bond. The catalytic activity of the triflate complexes 5OTf and 6OTf was evaluated in the allylation of aniline. Whereas the DMP-Xantphos derivative 6OTf exhibited a poor catalytic activity, very good conversion yields were obtained with the DPP-Xantphos complex 5OTf. On the basis of X-ray structure data and DFT calculations, it was concluded that the high catalytic activity of the DPP-Xantphos derivative complex [Pd(allyl)(3)]-[OTf] (6OTf) results from the combination of two effects: a large P-Pd-P bite angle, which enhances the reactivity of the allyl ligand, and the strong pi-accepting capacity of the diphenylphosphole moiety, which allows the easy formation of a 14-VE complex.

International audience; Mixtures of 2,4- and 2,5-disubstituted zirconacyclopentadienes were obtained by the reductive dimerisation of terminal alkynes using the Cp2ZrCl2/lanthanum system. Reactions of dihalophosphines with these mixtures afforded selectively the corresponding 2,4-disubstituted phospholes and 1,4-disubstituted butadienes. A new series of phospholes was characterized by multi-nuclear NMR spectroscopy and X-ray analysis. A possible explanation for the observed selectivity was obtained from X-ray studies and DFT analysis of the intermediate zirconacyclopentadienes.

International audience; Enantiopure 2-(chlorocarbonyl)phosphametallocenes [MCp*(2-{COCl}-3,4-Me2-5-Ph-PC4)] (M = Fe, Ru) react with phospholide anions to give 2-phosphametallocene-2′-acylphospholides K[MCp*(2-CO-2′-{3′,4′-Me2-5′-PhPC4}-3,4-Me2-5-Ph-PC4)] (M = Fe, Ru) and these have been converted into keto-bis-(2-phosphametallocene)s through reaction with [FeClCp*(tmeda)]; templation of this process with CuBr gives rise to the C2- (or pseudo-C2- when M = Ru) symmetric form of [{MCp*(3,4-Me2-5-Ph-PC4)}2-2,2′-(CO)] (M = Fe, Ru; Fe, Fe) with high (>95%) diastereoselectivity. X-Ray structures of these ligands coordinated to [RuCp*Cl] and [PtCl2] centres show that the spatial orientation of the very flexible keto-bis-(2-phosphametallocene) structure is highly responsive to the coordination sphere of the chelated platinum or ruthenium centre.