Voici les éléments 1 - 8 sur 8
  • Publication
    Métadonnées seulement
    Ru-4(mu-CO)(CO)(9)(eta(4)-mu(4)-C6H4)(eta(2)-mu(1), mu(4)-PPhCH2CH2PPh2): an unusual pyrolysis product of Ru-3(CO)(10)(dppe) containing a benzyne ligand
    (2002)
    Diz, Enrique Lozano
    ;
    Neels, Antonia
    ;
    ;
    The thermal decomposition of Ru-3(CO)(10)(dppe) in refluxing benzene gives, in contrast to the pyrolysis of the dppm analogue, the tetranuclear cluster Ru-4(mu-CO)(CO)(9)(eta(4)-mu(4)-C6H4) (eta(2)-mu(1), mu(4)-PCH2CH2PPh2) (1) along with Ru-3 (CO)(9)(eta(2)-mu(1), mu(2)-C6H5)(eta(3)-mu(1), mu(2)-PPhCH2CH2PPb2) (2). The single-crystal structure analysis of 1 reveals a square-planar tetraruthenium skeleton containing a eta(4)-mu(4)-benzyne ligand as well as a eta(2)-mu(1), mu(4)-phosphinidene-phosphine ligand. (C) 2002 Elsevier Science B.V. All rights reserved.
  • Publication
    Métadonnées seulement
    New Ru-3(CO)(12) derivatives with bulky diphosphine ligands: synthesis, structure and catalytic potential for olefin hydroformylation
    (2001)
    Diz, Enrique Lozano
    ;
    Neels, Antonia
    ;
    ;
    The diphosphine clusters Ru-3(CO)(10)(dcpm) (1) and Ru-3(CO)(10)(F-dppe) (2) as well as the bis(diphosphine) clusters Ru-3(CO)(8)(dcpm)(2) (3) and Ru-3(CO)(8)(F-dppe)(2) (4) have been synthesised from Ru-3(CO)(12) and the bulky diphosphines 1,2-bis[bis(pentafluorophenyl)phosphino]ethane (F-dppe) and bis(dicyclohexylphosphino)methane (dcpm). While the single-crystal X-ray structure analyses of 1, 2 and 3 show the expected mu (2)-eta (2) coordination of the diphosphine ligands, that of 4 reveals an unusual structure with one mu (2)-eta (2)-diphosphine and one mu (1)-eta (2)-diphosphine ligand. The clusters 1-4 catalyse the hydroformylation of ethylene and propylene to give the corresponding aldehydes, 2 showing higher activities than those observed for Ru-3(CO)(12) and Ru-3(CO)(10)(dppc). (C) 2001 Elsevier Science Ltd. All rights reserved.
  • Publication
    Métadonnées seulement
    Conversion of ethylene into ethylidyne on a mixed-metal cluster: synthesis and structure of IrRu4(CO)(15)(mu(4)-CH3)
    (1999)
    Haak, Susanne
    ;
    Neels, Antonia
    ;
    ;
    The thermal reaction of the tetranuclear cluster HIrRu3(CO)(13) with ethylene in hexane (90 degrees C, 2 bar) affords, in addition to H3IrRu3(CO)(12), the pentanuclear cluster HIrRu4(CO)(15)(mu(4)-C-CH3) (1) in which the ethylidyne ligand is coordinated through a carbon atom to the four ruthenium atoms in the IrRu4 core. In this reaction, the CH2=CH2 molecule has been transformed into a C-CH3 moiety coordinated as a mu(4)-ligand to the cluster. (C) 1999 Elsevier Science S.A. All rights reserved.
  • Publication
    Métadonnées seulement
    Metal-framework degradation reactions of the mixed-metal cluster anions [M3Ir(CO)(13)](-) (M=Ru, Os) with bis(diphenylphosphino)methane and with tricyclohexylphosphine: synthesis and structure of HRu2Ir(CO)(5)(dppm)(3), HRu2Ir(CO)(6)(PCy3)(3), H2Os2Ir2(CO)(10)(PCy3)(2) and H3Os3Ir(CO)(8)(PCy3)(3)
    (1999)
    Haak, Susanne
    ;
    ;
    Neels, Antonia
    ;
    The mixed-metal cluster anions [M3Ir(CO)(13)](-) (M=Ru, Os) react in methanol under metal-framework degradation with bis(diphenylphosphino)methane (dppm) or tricyclohexylphosphine (PCy3) to give a series of neutral tri- and tetranuclear mixed-metal clusters. The reaction of [M3Ir(CO)(13)](-) (M=Ru, Os) with dppm leads to the phosphine-substituted hydrido derivatives HRu2Ir(CO)(5)(dppm)(3) (1) and HOs2Ir(CO)(5)(dppm), (2), respectively. The two 48e clusters show a triangular arrangement of the M2Ir skeleton. The dppm ligands are coordinated in bridging positions over each metal-metal edge; the hydride is bonded terminally to the iridium atom. Cluster degradation is also observed by treating [Ru3Ir(CO)(13)](-) with PCy3 in methanol, giving the highly electron-deficient (44e) mixed-metal cluster HRu2Ir(CO)(6)(PCy3)(3) (3). The reaction of the osmium homologue [Os3Ir(CO)(13)](-) with PCy3 under the same conditions leads to a mixture of the neutral tetranuclear clusters H2Os2Ir2(CO)(10)(PCy3)(2) (4) and H3Os3Ir(CO)(8)(PCy3)(3) (5). Both clusters, 4 and 5 still have a tetrahedral metal core like the starting cluster anion but in 4 an osmium atom has been replaced by an iridium atom. The molecular structures of 1, 3, 4 and 5 were confirmed by single-crystal X-ray structure analyses. (C) 1999 Elsevier Science Ltd. All rights reserved.
  • Publication
    Métadonnées seulement
    Tri- and tetranuclear mixed-metal clusters containing alkyne ligands: Synthesis and structure of [Ru3Ir(CO)(11)(RCCR ')](-), [Ru2Ir(CO)(9)(RCCR ')](-), and [HRu2Ir(CO)(9)(RCCR ')]
    (1999)
    Ferrand, Vincent
    ;
    ;
    Neels, Antonia
    ;
    The tetrahedral cluster anion [Ru3Ir(CO)(13)](-) (1) reacts with internal alkynes RC=CR' to afford the alkyne derivatives [Ru3Ir(CO)(11) (RCCR')](-) (2: R = R' = Ph; 3: R = R' = Et; 4: R = Ph; R' = Me; 5: R = R' = Me) which have a butterfly arrangement of the Ru,Ir skeleton in which the alkyne is coordinated in mu(4)-eta(2) fashion. Under CO pressure they undergo fragmentation to give the trinuclear cluster anions [Ru2Ir(CO)(9)(RCCR')](-) (6: R = R' = Ph; 7: R = R' = Et; 8: R = Ph; R' = Me; 9: R = R' = Me), in which the alkyne ligand is coordinated in a mu(3)-eta(2) parallel fashion. Protonation of these trinuclear anions leads to the formation of the corresponding neutral hydride clusters [HRu2Ir(Co)(9)(RC=CR')] (10: R = R' = Ph; 11: R = R' = Et; 12: R = Ph; R' = Me; 13: R = R' = Me). The protonation of the butterfly anions 2 and 3, however, gives rise to the formation of the neutral tetrahedral clusters [HRu3Ir(CO)(11)(RCCR')] (14: R = R' = Ph and 15: R = R' = Et), respectively. The analogous clusters [HRu3Ir(CO)(11)(PhCCCH3)] (16) and [HRu3Ir(CO)(11)(CH3CCCH3)] (17) are only accessible from the reaction of the neutral cluster [HRu3Ir(CO)(13)] with the corresponding alkynes. The complexes 2, 4, 5, 6, 10, 12 and 15 are characterised by Xray structure analysis.
  • Publication
    Métadonnées seulement
    Site-selective carbonyl substitution in the mixed-metal cluster anion [H2Ru3Ir(CO)(12)](-): synthesis and characterization of phosphine, phosphite, arsine and stibine derivatives
    (1999) ;
    Haak, Susanne
    ;
    Ferrand, Vincent
    ;
    Neels, Antonia
    ;
    The reaction of the mixed-metal carbonyl cluster anion [H2Ru3Ir(CO)(12)](-) with PPh3, PMe3, P(OPh)(3), AsPh3 or SbPh3 leads to the mono-substituted derivatives [H2Ru3Ir(CO)(11)L](-) (L = PPh3 1, L = PMe3 2, L = P(OPh)(3) 3, L = AsPh3 4, L = SbPh3 5). Protonation of the anions 1-5 gives the neutral trihydrido derivatives H3Ru3Ir(CO)(11)L (L = PPh3 6, L = PMe3 7, L = P(OPh)(3) 8, L = AsPh3 9, L = SbPh3 10). All new tetranuclear clusters invariably show a tetrahedral arrangement of the Ru3Ir skeleton, as predicted for 60 e systems. The ligand L is coordinated to one of the ruthenium atoms, except in the case of L = PMe3 where two substitution isomers are observed. While the anionic isomers [H2Ru3Ir(CO)(11)(PMe3)](-) (2) could not be separated, the corresponding neutral isomers H3Ru3Ir(CO)(11)(PMe3) (7) could be resolved by thin-layer chromatography. In isomer 7a, the phosphine ligand is coordinated to one of the ruthenium atoms, whereas in isomer 7b the PMe3 ligand is bonded to the iridium atom. The molecular structures of 1, 7b, 8 and 9 were confirmed by a single-crystal X-ray structure analysis. (C) 1999 Elsevier Science S.A. All rights reserved.
  • Publication
    Métadonnées seulement
    Reactions of the cationic complex [(eta(6)-C6Me6)(2)Ru-2(mu(2)-H)(3)](+) with nitrogen-containing heterocycles in aqueous solution
    (1998)
    Jahncke, Manfred
    ;
    Neels, Antonia
    ;
    ;
    The dinuclear cation [(eta(6)-C6Me6)(2)Ru-2(mu(2)-H)(3)](+) (1) reacts in aqueous solution with pyrazole and 4-methylpyrazole to give the bispyrazolato complexes [(eta(6)-C6Me6)(2)Ru-2(mu(2)-H)(mu(2)-eta(1),eta(1)-N2C3H2R)(2)](+) (R = H: 2, R = Me: 3). The reaction with 1,2,4-triazole results in the formation of the bistriazolato complex [(eta(6)-C6Me6)(2)Ru-2(mu(2)-H)(mu(2)-eta(1),eta(1)-N3C2H2)(2)](+) (4) Successive protonation of the triazolato ligands in 4 leads to the complexes [(eta(6)-C6Me6)(2)Ru-2(mu(2)-H)(mu(2)-eta(1),-N3C2H2)(mu(2)-eta(1),eta(1 )-N3C2H3)](2+) (5) and [(eta(6)-C6Me6)(2)RU2(mu(2)-H)(mu(2)-eta(1),eta(1)-N3C2H2)(2)](3+) (6). The reaction of 1 with 1,2,3-triazole gives a 1:1 mixture of the bistriazolato complexes [(eta(6)-C6Me6)(2)Ru-2(mu(2)-H)(mu(2)-eta(1),eta(1)-N3C2H2)(2)](+) with parallel (7a) and anti-parallel (7b) coordination of the triazolato ligands. The single-crystal X-ray structure analyses of 2 (hexafluorophosphate salt) and 4 (tosylate salt) reveal for both complex types a ruthenium-ruthenium backbone being bridged by the two heterocyclic ligands with the N-N axis coordinated in a mu(2)-eta(1),eta(1)-fashion. A single-crystal X-ray structure analysis of title complex 1 (hexafluorophosphate salt) confirms the presence of three bridging hydride ligands with a Ru-Ru distance of only 2.47 Angstrom. (C) 1998 Elsevier Science S.A. All rights reserved.
  • Publication
    Métadonnées seulement
    Amphiphilic organoruthenium oxomolybdenum and oxovanadium clusters
    (1998) ;
    Plasseraud, Laurent
    ;
    Ferrand, Vincent
    ;
    Stanislas, Sandrine
    ;
    Neels, Antonia
    ;
    ;
    Henry, Marc
    ;
    Laurenczy, Gábor
    ;
    Roulet, Raymond
    Para-cymene ruthenium dichloride dimer reacts in aqueous solution with sodium molybdate or sodium vanadate to give the amphiphilic clusters [(eta(6)-p-MeC(6)H(4)iPr)(4)Ru4Mo4O16] (1) and [(eta(6)-p-MeC(6)H(4)iPr)(4) Ru4V6O19] (4) respectively. The analogous reaction of hexamethylbenzene ruthenium dichloride dimer with sodium vanadate gives [(eta(6)-C6Me6)(4)Ru4V6O19] (5). The mixed-metal clusters [(eta(6)-p-MkC(6)H(4)iPr) Ru(eta(5)-C5Me5)(3)Rh3Mo4O16] (2) and [(eta(6)-p-MeC(6)H(4)iPr)(2)Ru-2(eta(5)-C5Me5)(2)Rh(2)Mo(4)O16] (3) are accessible from a mixture of para-cymene ruthenium dichloride dimer and pentamethylcyclopentadienyl rhodium dichloride dimer with sodium molybdate in aqueous solution. The crystal structure analyses of 1 and 3 reveal different framework geometries of the metal oxygen skeletons. O-17 NMR spectroscopy and partial charge calculations confirm the presence of three different types of oxygen atoms in 1. (C) 1998 Elsevier Science Ltd. All rights reserved.