Osmium Cluster Complexes Research Articles

Osmium−Bismuth Complexes from the Reaction of Os3(CO)11(NCMe) with BiPh3

Five new compounds were obtained from the reaction of Os(3)(CO)(11)(NCMe), 1, with BiPh(3) in hexane solution at reflux. These have been identified as Os(2)(CO)(8)(mu-BiPh), 2, Os(CO)(4)Ph(2), 3, Os(4)(CO)(14)(mu-eta(3)-O=CC(6)H(5))(mu(4)-Bi), 4, Os(4)(CO)(15)Ph(mu(4)-Bi), 5, and Os(5)(CO)(19)Ph(mu(4)-Bi), 6. Cleavage of the phenyl groups from the BiPh(3) was the dominant reaction pathway. Fragmentation of the original triosmium cluster was accompanied by reaggregation processes that were facilitated by the naked bismuth to yield the higher nuclearity osmium cluster complexes containing spiro-bridging bismuth ligands. Compound 6 was photo-decarbonylated to yield the compound HOs(5)(CO)(18)(mu-eta(2)-C(6)H(4))(mu(4)-Bi), 7, formed by ortho-CH activation of the sigma-bonded phenyl ring in 6 to form a bridging eta(2)-benzyne ligand. Compounds 2- 7 were each characterized structurally by a single-crystal X-ray diffraction analysis.

Facile Activation of Hydrogen by an Unsaturated Platinum−Osmium Cluster Complex

The electronically unsaturated platinum−osmium complex Pt2Os3(CO)10(PtBu3)2, 3, has been obtained from the reaction of Os3(CO)10(NCMe)2 with Pt(PtBu3)2. Compound 3 adds hydrogen at 0 °C to yield the dihydrido complex Pt2Os3(CO)10(PtBu3)2(μ-H)2, 4 (93% yield) within 10 min and subsequently the tetrahydrido complex Pt2Os3(CO)10(PtBu3)2(μ-H)4, 5, in 70% yield within 60 min. Compound 3 contains a trigonal bipyramidal cluster of five metal atoms having the two platinum atoms in the apical sites. With the addition of each equivalent of hydrogen, the trigonal bipyramidal cluster opens by series of Pt−Os bond cleavages that result in sequential shifts of the Pt groups to edges of the Os3 triangle. The hydrogen addition process can be reversed partially at 25 °C by purging solutions of 5 with nitrogen.

Reactions of Os3(CO)10(μ-H)2 with 1,8-Bis(ferrocenyl)octatetrayne Yield Products Involving Cyclizations and Trans-Hydrogenation of Alkyne Groups

The reaction of 1,8-bis(ferrocenyl)octatetrayne (1) with Os3(CO)10(μ-H)2 (2) yielded three new osmium cluster complexes containing two electroactive ferrocenyl groups: Os3(CO)9(μ3,η3-FcCCHC4COC⋮CFc)(μ-H) (3); Os3(CO)10(μ3,η2-E-FcCHCHC2−C⋮C−C⋮CFc) (4); and Os6(CO)20(μ3,μ3-η2-η2-E,E-FcCHCHC2−C2CHCHFc) (5). All three compounds were characterized by IR, 1H NMR, and single-crystal X-ray diffraction analyses. In compound 3, the tetrayne chain was coupled to a CO ligand and cyclized to form an eight-membered heterobicycle containing two five-membered rings that bridges a closed cluster of three osmium atoms. Compound 4 contains one triangular triosmium cluster. Compound 5 contains two triangular triosmium clusters. In both 4 and 5, both the hydride ligands were transferred from the cluster to an alkyne group to form an olefinic group with E-stereochemistry. A mechanism for trans-hydrogenation at a bimetallic site is proposed. Cyclic and differential pulse voltammetric measurements show two reversible one-electron oxidation peaks for compounds 3 and 4 for their inequivalent ferrocenyl groups. Compound 5 shows only one two-electron oxidation for the two ferrocenyl groups, indicating no significant electrocommunication between them.

A comparison of ferrocenyl carbenium/non-carbenium structures in isomeric osmium cluster complexes obtained from the reaction of bis-ferrocenylbutadiyne with Os 3(CO) 10(μ-py)(μ-H)

The reaction of Os 3(CO) 10(μ-η 2-py)(μ-H) ( 1) (py=NC 5H 4) with 1,4-bis(ferrocenyl)butadiyne ( 2) in the presence of Me 3NO has provided two new isomeric triosmium cluster compounds Os 3(CO) 9(μ-py)(μ 3,η 3-CCFcCCHFc) ( 3) (Fc=C 5H 4FeC 5H 5) and Os 3(CO) 9(μ-py)(μ 3,η 2-CCFcCCHFc) ( 4). Both products were characterized by IR, 1H-NMR and single crystal X-ray diffraction analysis. Both compounds contain a triply bridging 1,3-bisferrocenylallylcarbyne ligand in an open triosmium cluster. Two of the carbon atoms of the allyl portion of the bisferrocenylallylcarbyne ligand in 3 are coordinated to one osmium atom, but in 4 only one of these carbon atoms is coordinated, and the other carbon atom forms a planar trivalent carbenium center. The bisferrocenylallylcarbyne ligand was formed by insertion of 2 into the osmium-hydrogen bond and a 1–2-shift of one of the ferrocenyl groups along the butadiyne chain. Both compounds exhibit two reversible one electron oxidations for the ferrocenyl groups: for 3, E p=+0.34 and +0.67 V; for 4, E p=+0.47 and +0.61 V.

Hydrido-sulfido-bridged triangular Os3 cluster compounds with different phosphine ligand substitution patterns

In the course of our studies of trinuclear osmium cluster complexes with bridging sulfido and hydrido ligands, the new compounds Os3(μ-H)(μ-SR)(CO)9(PHCy2) (Cy = cyclo­hexyl) with R = phenyl, (I) (nona­carbonyl-1κ3C,2κ3C,3κ3C-di­cyclo­hexyl­phosphine-3κP-μ-hydrido-1:2κ2H-μ-phenyl­thio-1:2κ2S-triangulo-triosmium), [Os3H(C6H5S)(C12H23P)(CO)9], and R = naphthyl, (II) [nona­carbonyl-1κ3C,2κ2C,3κ4C-di­cyclo­hexyl­phosphine-2κP-μ-hydrido-1:2κ2H-μ-(2-naphthyl­thio)-1:2κ2S-triangulo-triosmium], [Os3H(C10H7S)(C12H23P)(CO)9], were prepared. We report on these two phosphine-substituted complexes, which exhibit perceptible changes of the Os—Os bond parameters due to the ligand-substitution pattern.

Synthesis and structural characterization of osmium cluster complexes containing 2-phenylazopyridine. Crystal structures of [Os 3(CO) 10(NC 5H 4NNC 6H 5)] and [Os 3(CO) 10(μ-H)(NC 5H 3NN(O)C 6H 5)

The reaction of [Os 3(CO) 10(MeCN) 2] with 2-phenylazopyridine (2-PAP) affords [Os 3(CO) 10(NC 5H 4NNC 6H 5)] ( 1), [Os 3(CO) 10(μ-H)(NC 5H 3NN(O)C 6H 5)] ( 2) and a violet product 3, which is an isomer of 1. In 1, the 2-PAP moiety acts as the rarely observed six-electron donor. Cluster 2 contains an ‘oxidized’ 2-PAP moiety bonding in the usual ortho-metallated mode of pyridine. Both clusters 1 and 2 have been fully characterized in solution by conventional spectroscopic methods and in the solid state by single crystal X-ray diffraction analysis. Crystals of 1 are orthorhombic, space group P2 12 12 1, Z = 4, with unit cell dimensions a = 9.123(1), b = 17.217(2), c = 16.168(2) A ̊ . Crystals of 2 are triclinic, space group P 1, Z = 2 , with unit cell dimensions a = 9.308(2), b = 11.250(2), c = 12.934(2) A ̊ , α = 77.23(1), β=72.26(1), γ=85.21(1)° .

Preparation and crystal structure of the cluster complex Os 7H 2(CO) 21P(OMe) 3

The new osmium cluster complex Os 7H 2(CO) 21P(OMe) 3, in which P(OMe) 3 is trimethylphosphite, has been synthesized and characterized by X-ray crystallographic analysis. This complex was prepared by the addition of P(OMe) 3 to Os 7H 2(CO) 21. Crystals are monoclinic, space group P2 1/ c, with a = 14.220(3), b = 12.071(3), c = 24.019(7) A ̊ , β = 109.63(2)° and Z = 4. The metal atom arrangement consists of a trigonal bipyramid sharing an equatorial vertex with a triangle. The phosphite ligand is bound to one of the outer vertices of the triangular unit. The physical and chemical behavior of this complex is compared with that of two previously reported clusters alleged to be isomers of Os 7H 2(CO) 22.

The coordination and activation of azetidine by a triosmium cluster

The ring opening of nitrogen-containing heterocycles is an integral step in the process of hydrogenitrogenatio. The mechanisms by which this step occurs are poorly understood; thus a considerable amount of research has been devoted to modeling this heterogeneous reaction by using homogeneous catalysts. Although it has considerable ring strain, the four-membered heterocycle, azetidine, is opened thermally only at temperatures in excess of 400[degrees]C. Recently, we have found that thietanes, the saturated four-membered heterocycles containing sulfur, undergo facile ring opening when the molecule is coordinated to osmium cluster complexes. It was shown that a bridging coordination of the sulfur atom promotes this process. Thus, we wondered if it might also be possible to open an azetidine ring in a cluster complex under conditions sufficiently mild that a detailed study of the process might be possible. We have now prepared an osmium cluster complex in which the nitrogen atom of the azetidine ligand bridges two of the metal atoms, and we have found that the azetidine ring is spontaneously opened when the complex is heated to 125[degrees]C. In addition, two other complexes formed by transformation of the azetidine ligand have been isolated and characterized. The results of this study are reported here.more » 20 refs., 4 figs., 13 tabs.« less

Ring opening of strained-ring heterocycles containing nitrogen by an osmium cluster complex

The osmium cluster complex Os{sub 3}(CO){sub 10}({mu}-NCH{sub 2}CH{sub 2}CH{sub 2})({mu}-H) (1) was obtained in 34% yield from the reaction of Os{sub 3}(CO){sub 10}(NCMe){sub 2} with azetidine. Complex 1 was characterized crystallographically and shown to contain a four-membered NCH{sub 2}CH{sub 2}CH{sub 2} ring bridging two of the metal atoms via the nitrogen atom. When heated to 125{degrees}C, 1 was transformed to the new complex Os{sub 3}(CO){sub 10}[{mu}-N=C(H)Et]({mu}-H) (2; 27% yield) by an opening of the four-membered ring and a hydrogen shift. Crystal data: for 1, space group P2{sub 1}/c, a = 8.793 (2) A, b = 16.265 (2) A, c = 13.766 (4) A, {Beta} = 110.56 (1){degrees}, Z = 4, 1872 reflections, R = 0.039; for 2, space group P1, a = 92.73 (2){degrees}, {Beta} = 99.03 (2){degrees}, {gamma} = 81.52 (2){degrees}, Z = 6, 4862 reflections, R = 0.024. 16 refs. 2 figs.

The activation of tertiary amines by osmium cluster complexes: Further studies of the reaction of Os3(CO)10(NCMe)2 with triethylamine

AbstractThe reactions of Os3(CO)12 and Os3(CO)10(NCMe)2 with NEt3 have been reinvestigated. Two new products, Os3(CO)10(μ‐CH2C(H)NEt2)(μ‐H)) (2) and Os3(CO)10(syn‐μ‐η1‐CHCHNEt2)(μ‐H) (3) were obtained in low yields, 4% and 7%, in addition to the previously reported compound Os3(CO)10(anti‐μ‐η1‐CHCHNEt2(μ‐H) (1) (20% yield) when the reaction was conducted at 25°C using Os3(CO)10(NCMe)2. Compounds 2 and 3 were characterized by IR, 1H NMR and single‐crystal X‐ray diffraction analyses. Compound 2 contains a bridging methyl‐metallated N‐ethylimine ligand formed by the cleavage of one ethyl group from the NEt3. Compound 3 is an isomer of 1 in which the bridging ligand has a syn conformation with respect to the cluster as compared with the anti conformation in 1. Compound 3 slowly isomerizes to 1. Compound 3 is de‐carbonylated by exposure to UV radiation and is transformed to the new compound Os3(CO)9(μ3‐CC(H)NEt2)(μ‐H)2 (4) (58% yield) by an additional CH activation to form a triply bridging η1‐diethylaminovinylidene ligand. Compound 4 isomerizes to the compound Os3(CO)9(μ3‐HCCNEt2)(μ‐H)2 (5) (70% yield) at 68°C. The latter contains a triply briding ynamine ligand which exhibits structural and reactivity features that are characteristic of a carbene ligand at the amine‐substituted carbon atom. Crystal data: for 2, space group = P21/c, a = 9.236(2) Å, b = 12.469(2) Å, c = 18.107(3) Å, β = 104.67(1)°, Z = 4, 2518 reflections, R = 0.031; for 3, space group = P21/m, a = 7.644(1) Å, b = 12.706(2) Å, c = 11.912(2) Å, β = 108.02(1)°, Z = 2, 1295 reflections, R = 0.030; for 4, space group = P21/n, a = 10.233(2) Å, b = 14.834(4) Å, c = 14.538(2) Å, β = 99.88(2)°, Z = 4, 2403 reflections, R = 0.036.

Promotion of ring-opening nucleophilic addition to thietane ligands by the bridging coordination of the sulfur atom in the osmium cluster complexes Os3(CO)10[.mu.-[cyclic]SCH2CMe2CH2] and Os3(CO)10[.mu.-trans-[cyclic]SC(H)MeCH2C(H)Me

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTPromotion of ring-opening nucleophilic addition to thietane ligands by the bridging coordination of the sulfur atom in the osmium cluster complexes Os3(CO)10[.mu.-[cyclic]SCH2CMe2CH2] and Os3(CO)10[.mu.-trans-[cyclic]SC(H)MeCH2C(H)Me]Richard D. Adams and Michael P. PompeoCite this: Organometallics 1992, 11, 4, 1460–1465Publication Date (Print):April 1, 1992Publication History Published online1 May 2002Published inissue 1 April 1992https://doi.org/10.1021/om00040a014RIGHTS & PERMISSIONSArticle Views41Altmetric-Citations20LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (766 KB) Get e-AlertsSupporting Info (1)»Supporting Information Supporting Information Get e-Alerts

Hydrosilation of alkynes by an osmium cluster complex. The isolation and structural characterization of an intermediate

Hydrosilation of alkynes by an osmium cluster complex. The isolation and structural characterization of an intermediate

Clusters containing carbene ligands. 13. Studies of the reactivity of a bridging aminocarbene center with diarylalkynes in an osmium cluster complex

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTClusters containing carbene ligands. 13. Studies of the reactivity of a bridging aminocarbene center with diarylalkynes in an osmium cluster complexRichard D. Adams and Gong ChenCite this: Organometallics 1991, 10, 9, 3028–3035Publication Date (Print):September 1, 1991Publication History Published online1 May 2002Published inissue 1 September 1991https://doi.org/10.1021/om00055a013RIGHTS & PERMISSIONSArticle Views26Altmetric-Citations6LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (980 KB) Get e-AlertsSupporting Info (1)»Supporting Information Supporting Information Get e-Alerts

Clusters containing carbene ligands. 1. Novel transformations of carbene ligands at multinuclear metal sites. .alpha.-Activation of carbon-hydrogen and sulfur-carbon bonds in carbene containing thiolatotriosmium carbonyl cluster compounds

Studies of transition-metal cluster compounds are revealing an increasing number of new and unusual ligand transformations that involve interactions at two or more metal sites. An understanding of the scope and mechanisms of these rearrangements will play a central role in developing the potential of these compounds to serve as reaction catalysts. In their recent studies they have discovered that the osmium cluster complex Os/sub 3/(CO)/sub 9/(..mu../sub 3/-CO)(..mu../sub 3/-S) will react with NMe/sub 3/ by a double C-H activation process to yield the product Os/sub 3/(CO)/sub 8/-(C(H)NMe/sub 2/)(..mu../sub 3/-S)(..mu..H)/sub 2/ which contains a terminally coordinated secondary aminocarbene ligand. This compound has been found to be a precursor for an effective catalyst for the exchange of alkyl groups in tertiary amines. They have now discovered that bis(dialkylamino)methanes can also serve as reagents for the introduction of secondary amino-carbene ligands into certain osmium cluster complexes and these engage in some very unusual and potentially important multicenter ligand transformations. These results are described in detail in this report.

Coupling of cumulenes to an alkyne ligand in an osmium cluster complex. The reactions of Os4(CO)11(.mu.4-HC2CO2Me)(.mu.4-S) with allene and methyl isocyanate

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTCoupling of cumulenes to an alkyne ligand in an osmium cluster complex. The reactions of Os4(CO)11(.mu.4-HC2CO2Me)(.mu.4-S) with allene and methyl isocyanateRichard D. Adams and Suning. WangCite this: Organometallics 1987, 6, 1, 45–49Publication Date (Print):January 1, 1987Publication History Published online1 May 2002Published inissue 1 January 1987https://doi.org/10.1021/om00144a011RIGHTS & PERMISSIONSArticle Views39Altmetric-Citations9LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (607 KB) Get e-AlertsSupporting Info (1)»Supporting Information Supporting Information Get e-Alerts

X-Ray structures of the hexanuclear cluster complexes [Os6(CO)18]2–, [HOs6(CO)18]–, and [H2Os6(CO)18

X-Ray analyses of three osmium cluster complexes has shown that two, [Os6(CO)18]2– and [HOs6-(CO)18]–, have the approximately regular octahedral structure expected for hexanuclear clusters with 86 valence electrons, but the third, [H2Os6(CO)18], has an unusual monocapped square-pyramidal Os6 arrangement.