Stoeckli-Evans, Helen

2001, Faure, Matthieu, Onidi, Anne, Neels, Antonia, Stoeckli-Evans, Helen, Süss-Fink, Georg

The dinuclear cation [(eta (5)-C5Me5)(2)Ir2(mu (2)-H)(3)](+) (1) reacts in aqueous solution with pyrazole and 4-methylpyrazole to give the bispyrazolato complexes [(eta (5)-C5Me5)(2)Ir-2(mu (2)-H)(mu (2)-eta (1),eta (1)-N2C3H2R)(2)](+) (R = H, 2; R = Me, 3). The reaction of complex 1 with 1,2,4-triazole results in the formation of the bistriazolato complex [(mu (5)-C5Me5)(2)Ir-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 (5)-C5Me5)(2)Ir-2(mu (2)-H)(mu (2)-eta (1),eta (1)-N3C2H2)(mu (2)-eta (1),eta (1)-N3C2H3)](2+) (5) and [(eta (5)-C5Me5)(2)Ir-2(mu (2)-H)(mu (2)-eta (1),eta (1)-H3C2H3)(2)](3+) (6). The reaction of 1 with 1,2,3-triazole gives a 1:1 mixture of the bistriazolato complexes [(eta (5)-C5Me5)(2)Ir-2(mu (2)-H)(mu (2)-eta (1),eta (1)-N3C2H2)(2)](+) with parallel (7a) and antiparallel (7b) coordination of the triazolato ligands. The X-ray structure analysis of 3 reveals a diiridium backbone which is bridged by two pyrazolato ligands, the N-N axis being coordinated in a mu (2)-eta (1),eta (1) fashion. (C) 2001 Elsevier Science B.V. All rights reserved.

1999, Haak, Susanne, Neels, Antonia, Stoeckli-Evans, Helen, Süss-Fink, Georg

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.

1999, Ferrand, Vincent, Süss-Fink, Georg, Neels, Antonia, Stoeckli-Evans, Helen

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.

1999, Haak, Susanne, Süss-Fink, Georg, Neels, Antonia, Stoeckli-Evans, Helen

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.

1999, Süss-Fink, Georg, Haak, Susanne, Ferrand, Vincent, Stoeckli-Evans, Helen

The cluster anion [Os3Ir(CO)(13)](-) (1) was prepared in 50% yield by reaction of Os-3(CO)(12) with [Ir(CO)(4)](-). The single-crystal X-ray structure analysis of the bis(triphenylphosphoranylidene)ammonium salt shows 1 to consist of a tetrahedral metal core with one of the 13 carbonyl ligands being bridging. Protonation of 1 led to the neutral cluster HOs3Ir(CO)(13) (2), whereas the hydrogenation gave the cluster anion [H2Os3Ir(CO)(12)](-) (3). The catalytic activity of 1 for the carbonylation of methanol was studied. Using CH3I as co-catalyst, catalytic turnover numbers up to 1800 were obtained (140 degrees C, 30 bar) within 14 h. (C) 1999 Elsevier Science B.V. All rights reserved.

1999, Süss-Fink, Georg, Haak, Susanne, Ferrand, Vincent, Neels, Antonia, Stoeckli-Evans, Helen

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.