Showing papers on "Osmium published in 1985"
121 citations
TL;DR: In this paper, Laviron's theoretical treatment of cyclic voltammograms for redox species confined to the electrode surface was modified so as to clarify the experimentally accessible physical quantities The resulting equations were applied to the analysis of the redox-electrode reactions in acidic media of surfactant polypyridine osmium and ruthenium complexes.
74 citations
TL;DR: In this paper, the quantum yields of hydrogen production were optimized as a function of the pH and the concentrations of the components of the Ru(bpy)32+/MV2+/edta/colloidal platinum model system (bpy ≡ 2,2′-bipyridine; MV2+ ≡ methylviologen; edta ≡ ethylenediaminetetraacetic acid).
64 citations
TL;DR: The main properties of reductional adsorption of CO2 on the platinum metals are studied in this article, where strongly chemisorbed particles are obtained on the surface which are the products of more profound reduction of CO 2 than to formic acid.
62 citations
TL;DR: Synthese de complexes a ponts peptides tels que [(NH 3 ) 5 Os III -L-Co III (NH 3 ), 5 ](BF 4 ) 5 ou L=iso(Pro) 0−4, iso(Phe) 2, iso(Gly) 2 (iso=isonicotinyl).
Abstract: Synthese de complexes a ponts peptides tels que [(NH 3 ) 5 Os III -L-Co III (NH 3 ) 5 ](BF 4 ) 5 ou L=iso(Pro) 0−4 , iso(Phe) 2 , iso(Gly) 2 (iso=isonicotinyl). Cinetique des transferts d'electron et parametres d'activation
61 citations
TL;DR: In this paper, the magnetic susceptibilities of a series of cluster carbonyl compounds of osmium have been measured by a high-sensitivity Faraday method and the evolution of certain aspects of "metallic" behaviour in the high-nuclearity clusters is revealed by a steady increase in the excess molecular susceptibility as the cluster size increases.
Abstract: The magnetic susceptibilities of a series of cluster carbonyl compounds of osmium have been measured by a high-sensitivity Faraday method and the evolution of certain aspects of ‘metallic’ behaviour in the high-nuclearity clusters is revealed by a steady increase in the excess molecular susceptibility as the cluster size increases. We also consider here ‘metallic’ status in the cluster compounds of other transition elements.
51 citations
TL;DR: It has been shown for the first time that conformational junction between contiguous right-handed B and left-handed Z segments can be recognized by a chemical probe.
Abstract: It has been shown for the first time that conformational junction between contiguous right-handed B and left-handed Z segments can be recognized by a chemical probe. Plasmid pRW751 containing (dC-dG)13 and (dC-dG)16 blocks was treated with osmium tetroxide, pyridine (a reagent known to be single-strand selective) at physiological ionic conditions (0.1 and 0.2 M NaCl) and neutral pH. Mapping of the osmium binding sites by restriction enzyme digestion followed by nuclease S1 cleavage has revealed selective binding of osmium at, or near to, the end of the (dC-dG)n segments proximal to the 95 bp lac sequence. The junction of the shorter (dC-dG)13 segment was modified to a substantially greater extent than that of the longer segment. Partial inhibition of DNA cleavage by BamHI was observed at the restriction sites neighbouring to the both (dC-dG)n segments as a result of DNA modification by osmium tetroxide. The site-selective modification occurred only in supercoiled and not in relaxed molecules. Differences in the sensitivity of the B/Z junctions in pRW751 to the osmium tetroxide were explained by different structural features of these junctions.
50 citations
TL;DR: Preparation et structure de Ru(S-Me 4 C 6 H) 4 (CO), Effet de la nature du coordinat L sur le potentiel de reduction du complexe [M(XR 4 (L)] as mentioned in this paper.
Abstract: Preparation et structure de Ru(S-Me 4 C 6 H) 4 (CO). Effet de la nature du coordinat L sur le potentiel de reduction du complexe [M(XR) 4 (L)]
49 citations
TL;DR: Preparation des agregats Os 4 (CO) 12 (AuPR 3 ) 2 qui reagissent rapidement avec les nucleophiles is described in this article.
30 citations
29 citations
TL;DR: Etude de complexes cationiques de bipyridene-2,2' de Ru et Os contenant η 2 -alcene, η2 -alcyne, CO, alkyl et hydrure.
Abstract: Etude de complexes cationiques de bipyridene-2,2' de Ru et Os contenant η 2 -alcene, η 2 -alcyne, CO, alkyl et hydrure
TL;DR: In this article, the arene endo-dicyclopentadiene complexes of zerovalent ruthenium and osmium M(e-arene)(e4-C10H12) (M = Ru, arene = C6Me6; M = Os, arenes = C 6H3Me3-1,3,5) with HPF6 gave monoprotonated salts [M(C 10H13)(e-AREne)]PF6.
TL;DR: Le compose du titre cristallise dans le systeme monoclinique, groupe P2 1 /m and sa structure est affinee jusqu'a R=2,5%.
TL;DR: In this paper, the reaction between the compounds [Os3(µ-H)(µ3-CH)(CO) and [Pt(C2H4)2{P(cyclo-C6H11)3}] in toluene at 80 °C was characterised by single-crystal X-ray diffraction studies.
Abstract: The reaction between the compounds [Os3(µ-H)(µ3-CH)(CO)10] and [Pt(C2H4)2{P(cyclo-C6H11)3}] in toluene at 80 °C affords two cluster complexes, one containing a single platinum atom [Os3Pt(µ-H)2(µ4-C)(CO)10{P(C6H11)3}](1), and the other two platinum atoms, [Os3Pt2(µ-H)2(µ4-C)(µCO)(CO)9{P(C6H11)3}2](2) Both have been characterised by single-crystal X-ray diffraction studies Compound (1) contains a triangle of osmium atoms [Os–Os 2828(1)–2906(1)A], with the Pt atom bonded to one osmium [Os(2)–Pt 2764(1)A] The carbido-carbon atom is irregularly bonded [190(2)–221(2)A] to all four metal atoms Each osmium atom is ligated by three terminal carbonyl ligands, whilst the platinum atom is bonded to a terminal carbonyl group and a P(cyclo-C6H11)3 moiety Two hydrido-ligands bridge the Os(1)–Os(3) and Os(1)-Os(2) vectors Compound (2) contains a square-planar arrangement comprising two osmium and two platinum atoms with the third osmium atom [Os(3)] bridging the Os(1)–Os(2) edge The angle between the planes Os(1)Os(2)Pt(1)Pt(2) and Os(1)Os(2)Os(3) is 764° The carbido-carbon atom is approximately equidistant [2065(11)T–2120(10)A] from all five metal atoms, and the metal–metal separations are Os–Os 2855(1)–2917(1), Os–Pt 2929(1)–2935(1), and Pt(1)–Pt(2) 2716(1)A Each osmium atom carries three terminal carbonyl ligands, whilst the platinum atoms are symmetrically bridged by a carbonyl ligand, and each is ligated by a P(cyclo-C6H11)3 group The two hydrido-ligands bridge equivalent edges [Os(1)–Os(3) and Os(2)–Os(3)] The nmr data (1H, 13C-{1H}, and 31P-{1H}) are all consistent with the structures established in the solid state Treatment of [Pt(C2H4)2{P(cyclo-C6H11)3}] with [Os3(µ-H)(µ-COMe)(CO)10] in toluene at ambient temperatures affords a pentanuclear metal complex [Os3Pt2(µ-H)(µ5-C)(µ-OMe)(µ-CO)(CO)9{P(C6H11)3}2](3), the structure of which was again determined by single-crystal X-ray diffraction Two platinum and two osmium atoms are arranged in a ‘buckled’ square with the third osmium atom [Os(3)] metal–metal bonded only to Os(1) As in (2), the carbido–metal distances are approximately equal [2075(22)–2144(20)A] Moreover, the metal–metal distances Os–Os [2813(1)–2853(1)A] and Os–Pt [2891(1)–2941(1)A] are rather similar to those in (2) but the Pt–Pt distance [2668(1)A] is noticeably shorter In (3) each osmium atom carries three terminal carbonyl ligands, while a single carbonyl group asymmetrically bridges the two platinum atoms [Pt–µ-CO 2032(23) and 1968(20)A] Each platinum bears a P(cyclo-C6H11)3 group, with the hydrido-ligand bridging the shorter of the two Pt–Os edges [Pt(1)–Os(1)] The nmr spectra are consistent with the structure established in the solid state though some dynamic behaviour is evident
Patent•
01 May 1985
TL;DR: In this article, a process for the preparation of metallic products from metal salts admixed with solvent wherein at least one of the metal salt and the solvent is easily reducible is described. But this process is restricted to the case where at least half of the salt and solvent is reducible.
Abstract: A process is disclosed for the preparation of metallic products from metal salts admixed with solvent wherein at least one of the metal salt and the solvent is easily reducible. The admixture is heated under hypercritical conditions of temperature and pressure to produce metallic products and a hypercritical fluid. The hypercritical fluid is subsequently removed from the reaction zone and the metallic product is collected. The metallic product includes pure metals selected from the group of silver, gold, platinum, palladium, ruthenium, rhodium, mercury, arsenic, rhenium, tellurium, iridium, osmium, and copper, and alloys and mixtures thereof. The metallic product ordinarily exists as finely divided powders which may be highly porous.
TL;DR: Treatment of [Os3(CO)8(H){Ph2PCH2P(Ph)C6H4}] with H2 affords a high yield of the unsaturated cluster as discussed by the authors, which has been characterised by X-ray crystallography.
Abstract: Treatment of [Os3(CO)8(H){Ph2PCH2P(Ph)C6H4}] with H2 affords a high yield of the unsaturated cluster [Os3(CO)8(H)2-(Ph2PCH2PPh2)] which has been characterised by X-ray crystallography.
TL;DR: In this article, the M=N=S-Cl group, M being molybdenum, tungsten, rhenium or osmium, was introduced.
Abstract: Syntheses, structures, spectral data and chemical properties of chlorothionitrene complexes are reported. These incorporate the novel M=N=S-Cl group, M being molybdenum, tungsten, rhenium or osmium.
TL;DR: Comparaison des reactivites des agregats a celle de l'analogue Ru comparative aison des reactions de substitution de Fe 3 (CO) 12 et Os 3 ( CO) 12 en solution d'hydrocarbure.
TL;DR: In this article, supported osmium clusters were prepared by the reaction of [H4Os4(CO)12] with the surface of γ-Al2O3 in refluxing n-octane.
TL;DR: Mesures des vitesses de transfert d'electron de OsL' 3 2+ a FeL 3 3+ (L et L'=bipyridyle-2,2' et derives) as mentioned in this paper.
Abstract: Mesures des vitesses de transfert d'electron de OsL' 3 2+ a FeL 3 3+ (L et L'=bipyridyle-2,2' et derives. Catalyse des reactions par les anions; energie d'activation
TL;DR: A partir d'agregats μ-methylene, on obtient des agregats µ-cetene [PPN][Os 3 (CO) 10 (μ-CH 2 CO)(μ-X] Reactivite
Abstract: A partir d'agregats μ-methylene, on obtient des agregats μ-cetene [PPN][Os 3 (CO) 10 (μ-CH 2 CO)(μ-X)]. Reactivite
TL;DR: The surface compositions of impregnated cathodes having coatings of pure osmium with thickness between 50 and 30,000 A or mixed Osmium-tungsten coatings were measured by Auger spectroscopy as discussed by the authors.
TL;DR: Reflectance data and photographic evidence are presented to support the hypothesis that the osmium disappearance is due to reaction with oxygen to form a volatile oxide.
Abstract: A number of samples of optical thin film materials were flown on Shuttle flight STS-8 as part of an experiment to evaluate their interaction with residual atomic oxygen in low earth orbit. Osmium was selected because of its usefulness as a reflective optical coating for far-UV instruments and for confirmation of results from previous Shuttle flights in which such coatings disappeared. Reflectance data and photographic evidence are presented to support the hypothesis that the osmium disappearance is due to reaction with oxygen to form a volatile oxide. Platinum and iridium, which were included for comparison, fared much better.
Journal Article•
TL;DR: Cinetique des reactivites des agregats a celle de l'analogue Ru as discussed by the authors, compare with reaction of Fe 3 (CO) 12 and Os 3 (OC) 12 par L=PPh 3, PBu 3, P(OPh) 3 and P(OMe) 3 en solution d'hydrocarbure.
Abstract: Cinetique des reactions de substitution de Fe 3 (CO) 12 et Os 3 (CO) 12 par L=PPh 3 , PBu 3 , P(OPh) 3 et P(OMe) 3 en solution d'hydrocarbure. Comparaison des reactivites des agregats a celle de l'analogue Ru
TL;DR: In this paper, the hydridic tri-iron and tri-osmium cluster anions [HM 3 (CO) 11 ] − (M = Fe, Os) have been employed as soluble and supported catalysts for the hydroformylation of 1-hexene.
TL;DR: Alumina-supported catalysts were tested for CO hydrogenation at 250-325 °C and 10 atm, the products being Schulz-Flory distributions of hydrocarbons with small yields of dimethyl ether as discussed by the authors.