Stoeckli-Evans, Helen

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.

2002, Laly, Myriam, Fidalgo, Eva Garcia, Stoeckli-Evans, Helen, Süss-Fink, Georg

The heteropolyoxometalate [(HAsAsMoMo8O34)-As-III-Mo-V-Mo-V-O-VI](6-) reacts in aqueous solution with an excess of sodium metaarsenite to give a new arsenomolybdate [(As5Mo4O20)-Mo-III-O-VI(OCH3)](2-) which crystallize as the tetrabutylammonium salt. The single-crystal X-ray structure analysis reveals a heteropolyoxometalate anion containing an unusual chain of five arsenic atoms linked to each other by bridging oxygen atoms. (C) 2002 Elsevier Science B.V. All rights reserved.

1999, Plasseraud, Laurent, Stoeckli-Evans, Helen, Süss-Fink, Georg

The title complex was obtained by reaction of [(eta(6)-p-Pr'C6H4Me)(4)Ru4Mo4O16] with methanol in the presence of p-hydroquinone. It contains an Mo2Ru2O2(OMe)(4) core consisting of two Mo2RuO(OMe)(3) half-cubes fused together to form a choir-like structure. (C) 1999 Elsevier Science S.A. All rights reserved.

1997, Jahncke, Manfred, Meister, Gotz, Rheinwald, Gerd, Stoeckli-Evans, Helen, Süss-Fink, Georg

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.

2001, Diz, Enrique Lozano, Neels, Antonia, Stoeckli-Evans, Helen, Süss-Fink, Georg

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.

1997, Ferrand, Vincent, Merzweiler, Kurt, Rheinwald, Gerd, Stoeckli-Evans, Helen, Süss-Fink, Georg

The electron-deficient cluster (mu(2)-H)Ru-3(CO)(9)[mu(3)-NS(O)MePh] (1) reacts with the terminal alkyne PhCH2C=CH to give the vinyl complex Ru-3(mu(2)-CO)(2)(CO)(6)[mu(3)-NS(O)MePh](mu(2)-eta(1),eta(2)-PhCH2C=CH2 ) (2). The analogous reaction with internal alkynes (RC=CR') affords the clusters Ru-3(mu(2)-CO)(CO)(7)[mu(3)-NS(O)MePh](mu(3)-eta(1),eta(2)-RC=CHR') (3: R = R' = Pr "; 4: R = Ph; R' = Bu ") in which the vinyl ligand has opened a Ru-Ru bond upon coordination the Ru-3 framework. In the case of diphenylacetylene, reaction with two equivalents of the alkyne, yields the vinyl-alkyne cluster (mu(2)-H)Ru-3(CO)(6)(mu(2)-eta(1),eta(2)-PhC=CHPh)(mu(3)-eta(1),eta(2)-P hC=CPh)[mu(3)-eta(1),eta(2)-NS(O)Me(C6H4)] (5) with ortho-metallation of the phenyl substituent of the sulfoximido cap. (C) 1997 Elsevier Science S.A.

1997, Süss-Fink, Georg, Plasseraud, Laurent, Ferrand, Vincent, Stoeckli-Evans, Helen

2002, Thomas, Christophe M., Mafua, Roger, Therrien, Bruno, Rusanov, Eduard, Stoeckli-Evans, Helen, Süss-Fink, Georg

The new diphosphine ligands Ph2PC6H4C(O)X(CH2)2OC(O)C6H4PPh2 (X = NH; X = NPh; X = O) and Ph2PC6H4C(O)O(CH2)2O(CH2)2OC (O)C6H4PPh2 (I) as well as the monophosphine ligand Ph2PC6H4C(O)X(CH2)2OH (II) have been prepd. from 2-diphenylphosphinobenzoic acid and the corresponding amino alcs. or diols. Coordination of the diphosphine ligands to rhodium, iridium, and platinum resulted in the formation of the square-planar complexes. In all complexes, the diphosphine ligands are trans coordinated to the metal center, thanks to the large spacer groups, which allow the two phosphorus atoms to occupy opposite positions in the square-planar coordination geometry. The trans coordination is demonstrated unambiguously by the single-crystal X-ray structure anal. of on of these complexes. In the case of the diphosphine ligand I, the spacer group is so large that dinuclear complexes with ligand I in bridging positions are formed, maintaining the trans coordination of the P atoms on each metal center, as shown by the crystal structure anal. of another complex. The monophosphine ligand II reacts with [{Ir(cod)Cl}2] (III) (cod = cyclooctadiene) to give the simple deriv. [Ir(cod)Cl] which is converted into the carbonyl complex [Ir(CO)2Cl] with carbon monoxide. The crystal structure anal. of III also reveals a square-planar coordination geometry in which the phosphine ligand occupies a position cis with respect to the chloro ligand. Some of these diphosphine ligands have been tested as cocatalysts in combination with the catalyst precursors [{Rh(CO)2Cl}2] and [{Ir(cod)Cl}2] or [H2IrCl6] for the carbonylation of methanol at 170°C and 22 bar CO. The best results (TON 800 after 15 min) are obtained for the combination X = NPh/[{Rh(CO)2Cl}2]. After the catalytic reaction, one complex is identified in the reaction mixt. and can be isolated; it is active for further runs without loss of catalytic activity. [on SciFinder(R)]

1995, Renouard, Corinne, Stoeckli-Evans, Helen, Süss-Fink, Georg