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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.

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.

Stable nucleophilic carbene compounds have recently been shown to be able to mimic in some instances the reactivity of metal fragments in the reaction of unactivated E-H bonds (E = H, R3Si, NH2, R2P). However, the insertion into a B-H bond of the strongly Lewis acidic BH3 molecule has never been observed at a single C atom or even at a metal fragment. Our results show that designed stable, highly electrophilic carbenoid fragments in compounds 4 and 6 can achieve this reactivity in a controlled manner. Density functional theory calculations corroborated the experimental results on the presently designed systems as well as the lack of reactivity on nucleophilic carbenes.

International audience

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.

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.

The LiCH2PPh2═NPh derivative 2 was cleanly prepared from the aminophosphonium salt [PhNH−PPh3+][Br−] (1) and MeLi. After formation of the iminophosphorane PPh3═NPh, nucleophilic displacement of one...

Bis(iminophosphoranyl)methanide ({CH(PPh2NR)}−, R = iPr or Ph) neodymium(III) complexes were prepared from NdI3(THF)3.5. The steric bulk of the ligand controlled the stoichiometry of the resulting complexes. Thus, three new complexes, bearing one or two ancillary ligands, were prepared and characterized using various spectroscopic techniques and by single-crystal X-ray diffraction. Reaction of the heteroleptic neodymium iodide complexes with amido groups yielded viable initiators for the ring-opening polymerization of lactide. The polymerizations were conducted using either the heteroleptic neodymium amido complexes or the in situ generated alkoxide complexes. Using such conditions, the neodymium complexes showed very fast and well-controlled polymerizations, with complete conversion being obtained in only a few minutes and yielding polylactide with controlled molecular weight and narrow polydispersity index. An initiating system comprising a rare neodymium-alkyl-carbene complex [Nd{C(PPh2NiPr)2}{CH(PPh2N...

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.

Highly reactive: The first divalent organoneodymium complex has been isolated and characterized by X-ray crystallography. It reacts immediately with all common aromatic and ethereal solvents, reduces dinitrogen to form an isolable dinitrogen complex, and undergoes C[BOND]H activation of a ligand tert-butyl group to form a crystallizable "tuck-in" complex (see scheme).

The novel tetradentate ligand 1, associating two phosphines and two iminophosphorane moieties, was easily synthesized from commercially available bis(diphenylphosphino)methane and ethylenediamine via the preparation of the bis(phosphine−aminophosphonium) adduct 1-(HBr)2. Deprotonation of this salt afforded the corresponding tetradentate P2N2 phosphine−iminophosphorane ligand 1. Coordination to Ni(II) and Pd(II) metal centers afforded complexes 2 and 3, respectively, characterized by multinuclear NMR and X-ray analysis. Both cationic complexes adopt a square-planar geometry around the metal, all phosphorus and nitrogen atoms being coordinated. In contrast to most iminophosphorane complexes, 2 and 3 could be handled in water without any apparent decomposition. Their catalytic activity was evaluated in Suzuki−Miyaura coupling. These reactions were conducted in toluene, water, or a biphasic toluene/water medium in the presence of a phase-transfer agent. Under these last conditions, the Pd catalyst 3 (0.1 mol ...

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.

Reaction of 1-bromo-2,5-diphenylphosphole with 10,11-dihydro-5H-dibenzo[b,f]azepine resulted in the formation of the corresponding aminophosphole 3, which was structurally characterized. Reaction of 3 with [Rh2(μ-Cl)2(C2H4)4] and [Rh(COD)2][BF4] afforded the complexes [Rh2(μ-Cl)2(3)2] (4) and [Rh(COD)(3)][BF4] (5), respectively. In both complexes, characterized by NMR as well as by X-ray crystallography, ligand 3 behaves as a chelate through coordination of the phosphorus atom and the olefinic part of the ligand to the rhodium center. The activity of both complexes was tested in the hydroformylation of mono- and disubstituted olefins at 20 bar of CO/H2 pressure. Complex 5 proves to be the most efficient catalyst.

The availability of bis(aminophosphoranes) 2a–c through a straightforward synthesis yielded access to a whole family of N,N ligands via sequential deprotonation. The obtained cationic 3a–c, neutral 4a–c, anionic 5a–c and dianionic 6a–c compounds were fully characterized by NMR and X-ray crystallography. Monocations 3a–c were shown to result from the deprotonation of 2a–c at the bridging methylene carbon. DFT calculations evidenced a substantial negative charge at this carbon. For the neutral bis(iminophosphoranes) 4a–c, two different forms were experimentally observed depending on the nature of the substituent at nitrogen. In the presence of an aryl group, a bis(iminophosphorane) is obtained whereas with alkyl substituent a tautomeric form resulting from a (1,3) hydrogen shift is observed. Theoretical studies were in good agreement with experimental results showing that these two forms are close in energy. The structure obtained for monoanion 5a reveals that a substantial interaction occurs between the anionic carbon and the lithium cation. The X-ray crystal structure of the optically pure dianion 6b has also been recorded.

Four discrete Mn(III)/Mn(II) tetranuclear complexes with a double-cuboidal core, [Mn(4)(hmp)(6)(CH(3)CN)(2)(H(2)O)(4)](ClO(4))(4).2CH(3)CN (1), [Mn(4)(hmp)(6)(H(2)O)(4)](ClO(4))(4).2H(2)O (2), [Mn(4)(hmp)(6)(H(2)O)(2)(NO(3))(2)](ClO(4))(2).4H(2)O (3), and [Mn(4)(hmp)(6)(Hhmp)(2)](ClO(4))(4).2CH(3)CN (4), were synthesized by reaction of Hhmp (2-hydroxymethylpyridine) with Mn(ClO(4))(2).6H(2)O in the presence of tetraethylammonium hydroxide and subsequent addition of NaNO(3) (3) or an excess of Hhmp (4). Direct current (dc) magnetic measurements show that both Mn(2+)-Mn(3+) and Mn(3+)-Mn(3+) magnetic interactions are ferromagnetic in 1-3 leading to an S(T) = 9 ground state for the Mn(4) unit. Furthermore, these complexes are single-molecule magnets (SMMs) clearly showing both thermally activated and ground-state tunneling regimes. Slight changes in the [Mn(4)] core geometry result in an S(T) = 1 ground state in 4. A one-dimensional assembly of [Mn(4)] units, catena-{[Mn(4)(hmp)(6)(N(3))(2)](ClO(4))(2)} (5), was obtained in the same synthetic conditions with the subsequent addition of NaN(3). Double chairlike N(3)(-) bridges connect identical [Mn(4)] units into a chain arrangement. This material behaves as an Ising assembly of S(T) = 9 tetramers weakly antiferromagnetically coupled. Slow relaxation of the magnetization is observed at low temperature for the first time in an antiferromagnetic chain, following an activated behavior with Delta(tau)/k(B) = 47 K and tau(0) = 7 x 10(-)(11) s. The observation of this original thermally activated relaxation process is induced by finite-size effects and in particular by the noncompensation of spins in segments of odd-number units. Generalizing the known theories on the dynamic properties of polydisperse finite segments of antiferromagnetically coupled Ising spins, the theoretical expressions of the characteristic energy gaps Delta(xi) and Delta(tau) were estimated and successfully compared to the experimental values.

A hexanuclear Mn(II) complex [Mn6(Hpao)4(pao)8](ClO4)4 (1) and a nonanuclear mixed-valent Mn complex [Mn9(μ4–O)2(μ3–O)4(CH3CO2)4(pao)8(Hpao)2] · 4H2O (2) have been synthesized from the reaction of simple Mn(II) salts with syn-2-pyridinealdoxime (Hpao) in the presence of base. Structural characterization reveals in both cases the presence of protonated uncoordinated oxime functions, a topology solely held by oxime bridges in 1 and rare Mn(II)–Mn(III)–Mn(IV) mixed-valences in 2. Magnetic studies reveal a spin ground state of S = 0 for complex 1.

Two coordination polymers [MII(H2O)2]2[MoIV(CN)8]·4H2O [MII = Co (1), Mn (2)] were prepared as monocrystals and structurally characterised. These compounds crystallise in the tetragonal systems I4/m (1) and I4/mcm (2) and form three-dimensional networks containing channels occupied by two types of water molecules, i.e. coordinated to MII and crystallised ones. The dehydration of these materials occurs topochemically to give [MII(H2O)]2[MoIV(CN)8] compounds having an open metal coordination site on the MII ions that may be accessible to coordination by other species and serve as a reaction site. The intercalation of water, ammonia and amines has been studied. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)

We report a one-step synthesis of the phosphine, PPh(2)(i)C(3)F(7) from commercially available precursors. The stereoelectronic properties of the phosphine were probed by coordination to transition metals. Mo(CO)(5)PPh(2)(i)C(3)F(7) was synthesised and the synthesis and structure of trans-PtCl(2)(PPh(2)(i)C(3)F(7))(2) are described. PPh(2)(i)C(3)F(7) was found to be a bulky electron-withdrawing ligand.

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.

Various Ugi—Smiles adducts can be transformed into isoquinolines or isoindoles depending on the conditions.

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.

The synthetic outcome of the Friedel-Crafts acylation of 1',2',3,3',4,4',5'-heptamethylphospharuthenocene reflects the nature of the acylating agent, with alkanoyl anhydride/trifluoromethanesulfonic acid (TfOH) reagents giving monosubstitution at the phospholyl ring, whereas alkanoyl chloride/AlCl 3 gives 2,5-disubstitution. DFT calculations indicate that this unusual double acylation can be facilitated by the intervention of the phosphorus atom at an early stage in the reaction trajectory, with the acyl group being delivered from the phosphorus atom into the ring 2- or 2,5-positions.

Enantiopure undecagold clusters protected by chiral atropisomeric diphosphine ligands (P^P) have been synthesized by the stoichiometric reduction of the corresponding (P^P)(AuCl)(2) complexes with NaBH(4). The molecular mono-disperse [Au(11)(P^P)(4)Cl(2)]Cl species have been thoroughly characterized using an array of analytical techniques. (31)P NMR experiments suggested the presence of a slow intramolecular ligand exchange process. Circular dichroism measurements showed that enantiomeric clusters display mirror-image chiroptical activity. Such undecagold clusters containing two chloride ligands bound to the peripheral Au(I) atoms were expected to display a carbophilic Lewis acidity similar to the well-documented molecular Au(I) complex catalysts. Chloride abstraction, performed to generate active Au(+) sites, induced the Au(11) cluster evolution to larger gold clusters and nanoparticles, together with Au(I) complexes, which, in fact, perform the catalysis. This result was corroborated by running an asymmetric tandem hydroarylation-carbocyclization reaction, for which the enantiomeric excesses obtained with Au(11) clusters are similar to those reported using Au(I) complexes.

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.

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.

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.

New P-N ligands featuring a phosphino group and an iminophosphorane moiety were successfully employed in the nickel-catalysed dimerisation of ethylene.

[NH(4)](2)Mn(3)(H(2)O)(4)[Mo(CN)(7)](2).4H(2)O (1) has been synthesized by slow diffusion of aqueous solutions containing K(4)[Mo(CN)(7)].2H(2)O, [Mn(H(2)O)(6)](NO(3))(2), and (NH(4))NO(3). Compound 1 crystallizes in the monoclinic C2/c space group. The basic motif of the three-dimensional structure consists of a Mo1-Mn1 gridlike sheet parallel to the bc plane. Two of these sheets are connected through CN-Mn2-NC linkages to form a bilayer reminiscent of the K(2)Mn(3)(H(2)O)(6)[Mo(CN)(7)](2).6H(2)O (2) two-dimensional structure. In 1, [NH(4)](+) cations allow these bilayers to be connected through direct Mo1-CN-Mn1 bridges to form a three-dimensional network, whereas in 2, they are isolated by (H(2)O)K(+) cations. As shown by the magnetic measurements, this increase of dimensionality by counterion substitution induces an enhancement of the ferrimagnetic critical temperature from 39 K in 2 to 53 K in 1.

Two coordination polymers [MII(H2O)2]2[MoIV(CN)8]·4H2O [MII = Co (1), Mn (2)] were prepared as monocrystals and structurally characterised. These compounds crystallise in the tetragonal systems I4/m (1) and I4/mcm (2) and form three-dimensional networks containing channels occupied by two types of water molecules, i.e. coordinated to MII and crystallised ones. The dehydration of these materials occurs topochemically to give [MII(H2O)]2[MoIV(CN)8] compounds having an open metal coordination site on the MII ions that may be accessible to coordination by other species and serve as a reaction site. The intercalation of water, ammonia and amines has been studied. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)

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.

[Rh(P2N2)X] complexes (2-X, X = Cl, BF4) featuring a tetradentate iminophosphorane phosphine ligand were synthesised and characterised. X-Ray analysis provides evidence for a square planar geometry without coordination of the chloride anion. These complexes proved to be air-sensitive, and their oxidation to Rh(iii) complexes 3-X was observed in air. The controlled reaction of 2-BF4 with one equivalent of hexachloroethane yielded [Rh(P2N2)Cl2(BF4)] (3-BF4). Direct synthesis of 3-Cl can also be achieved by coordination of the [P2N2] ligand to [RhCl(THT)3] (THT = tetrahydrothiophene). The reactivity of Rh(i) complexes 2 was further investigated, and no reaction was observed with silanes, aryl halides, or pinacolborane, although decomposition was observed under 1 atm of H2 upon prolonged heating. Interestingly, reduction of complex 3-Cl was observed by NMR upon treatment with silanes or sodium isopropoxide. Therefore, complex 3-Cl was used for catalytic transfer hydrogenation of polar bonds. The reduction of aromatic and aliphatic ketones can be carried out using 1% catalyst and 10% sodium isopropoxide, while imines are partially reduced under these conditions.

Convenient syntheses of 2,5-diester-substituted phosphametallocenes and 2,2′,5,5′-tetraester-substituted-1,1′-diphosphaferrocenes are described. Studies of the reactivity of alkali metal 3,4-dimethylphospholide, 2-ester-3,4-dimethyl phospholide and 2,5-diester-3,4-dimethylphospholide anions towards iron(II) centres (as [Fe(AlCl4)2] or [Fe(MeCN)6(BF4)2]) indicate that the corresponding 1,1′-diphosphaferrocenes are obtained without any complications resulting from redox chemistry at the iron centre.

International audience; Bis(aminophoshonium) salts derived from bis(diphenylphosphino)methane were prepared and triply deprotonated with potassium hexamethyldisilazane to yield the corresponding bis(iminophosphoranyl)methanides, which were then subjected to coordination with CrIIICl3(THF)3. Binuclear complexes of type [(HC(PPh2NR)2Cr(-Cl)(Cl))2] (R = iPr, tBu) with an octahedral coordination geometry and a long C–Cr bond were obtained and structurally characterized. In the case of R = o-MeO-C6H4, a monomeric species featuring no C–Cr bond is observed. Preliminary evaluation of catalytic activities of these complexes in ethylene oligomerization and polymerization is reported.

Serendipitous deprotonation of bis(iminophosphoranyl)methanide Nd(III) complexes afforded the first alkyl-carbene neodymium complex. Due to the presence of structurally similar methanide and methandiide fragments, this complex features, as evidenced by X-ray crystallographic analysis, Nd-C single and multiple bonds.

A dinuclear cobalt capsule [PF(6) subset(CH(3)CN)(2)(Co(2)L(4))][PF(6)](3) (2), (L = bis-benzimidazole-1,3-phenylene) has been prepared using a self-assembly approach. This unique class of cage is perfectly designed to encapsulate weakly coordinated anions, i.e. BF(4)(-) and PF(6)(-)via an Manion weak interaction as illustrated by X-ray and solid-state NMR investigations. Selective anion binding for BF(4)(-) over PF(6)(-) is also observed.

White phosphorus, P4, was reacted in a stoichiometric manner with Ni(0) complexes or particles to produce nanoparticles of nickel phosphide.