86885-48-5Relevant academic research and scientific papers
Coordination and scission of alkynes on a tungsten-triosmium framework. Crystal structures of (η5-C5H5)WOs3(CO) 10[μ3η2-C2(C 6H4CH3)2]H and (η5-C5H5)WOs3(CO) ...
Park, Joon T.,Shapley, John R.,Bueno, Clifford,Ziller, Joseph W.,Churchill, Melvyn Rowen
, p. 2307 - 2316 (2008/10/08)
Full title: Coordination and scission of alkynes on a tungsten-triosmium framework. Crystal structures of (η5-C5H5)WOs3(CO) 10[μ3η2-C2(C 6H4CH3)2]H and (η5-C5H5)WOs3(CO) 10[μ3-η2-C2(CO 2C2H5)2]H - species with an alkyne ligand bound to Os3 and WOs2 faces of tetrahedral WOs3 clusters. Reactions of CpWOs3(CO)12H (Cp = η5-C5H5) with various alkynes (RC≡CR′) produce two isomeric (symmetrical and/or unsymmetrical) alkyne complexes CpWOs3(CO)10(μ3-η2-C 2RR′)H [R = R′ = H, Ph, Tol, CF3, CO2Et; R = Ph, R′ = Tol; R = Ph, R′ = CO2Et] (Ph = C6H5, Tol = p-C6H4CH3) depending on the substituents R and R′ of alkynes. Some of the symmetrical isomers (R = CF3, CO2Et) undergo irreversible thermal isomerization to the unsymmetrical isomers. The diarylalkyne complexes (R = R′ = Ph, Tol; R = Ph, R′ = Tol) undergo facile intramolecular C≡C bond scission reactions after CO loss by Me3NO to yield the corresponding dialkylidyne clusters CpWOs3(CO)9(μ3-CR)(μ 3-CR′)H in ca. 60% yield along with alkyne-oxo clusters CpWOs3(CO)8(μ-O)(μ3-η 2-C2RR′)H in ca. 10% yield. The isomeric alkyne complexes, alkyne-oxo clusters, and dialkylidyne clusters have been isolated as crystalline solids and have been characterized by spectroscopic (infrared, mass, 1H and 13C NMR) data. CpWOs3(CO)10(μ3-η2-C 2Tol2)H crystallizes in the centrosymmetric monoclinic space group P21/n (No. 14) with a = 23.600 (5) A?, b = 9.343 (2) A?, c = 28.774 (4) A?, β = 97.39 (2)°, V = 6292 (2) A?3, and Z = 8. The structure solution converged with RF = 5.0% for those 4223 reflections with |F0| > 3.0σ(|F0|) and RF = 8.6% for all 5816 independent data (Mo Kα?, 2θ = 4.5-40.0°). There are two essentially equivalent molecules in the crystallographic asymmetric unit. Each consists of a tetrahedral WOs3 cluster in which the C2Tol2 ligand is bound to an Os3 face (π-bonded to Os(3) and σ-bonded to Os(1) and Os(2)). Os(3) bears two terminal carbonyl ligands, while Os(1) and Os(2) each have three. The W atom has two CO ligands, one of which is involved in a semibridging manner with the otherwise electron-poor Os(3); the hydride ligand (not located directly) is believed to span the Os(1)-Os(2) linkage. CpWOs3(CO)10(μ3-η2-C 2(CO2Et)2)H crystallizes in the centrosymmetric triclinic space group P1 (No. 2) with a = 9.121 (4) A?, b = 9.964 (3) A?, c = 15.729 (4) A?, α = 85.63 (2)°, β= 83.30 (3)°, γ = 85.74 (3)°, V = 1412.5 (8) A?3, and Z = 2. Refinement converged with RF = 4.87% for those 4240 data with |F0| > 3.0σ(|F0|) and RF = 5.55% for all 4868 independent data (Mo Kα?, 2θ = 4.5-50.0°). The molecule contains a tetrahedral WOs3 cluster, with the C2(CO2Et)2 ligand now bound to a WOs2 face (π-bonded to W and σ-bonded to Os(1) and Os(3)). The Os atoms each bear three terminal CO ligands, while the W atom has only one.
Formation of tungsten-triosmium clusters. Crystal structure and reactivity of (η5-C5H5)WOs3(CO) 12(μ3-CC6H4CH 3)(μ-H)2
Chi, Yun,Shapley, John R.,Churchill, Melvyn Rowen,Li, Yong-Ji
, p. 4165 - 4170 (2008/10/08)
Previous studies have identified three mixed-metal clusters (1-3) as the major products from the reaction of CpW(CO)2(CTol) (Cp = η5-C5H5; Tol = p-C6H4CH3) and H2Os3(CO)10. A fourth, minor, product has been isolated and identified spectroscopically as CpWOs3(CO)12(μ3-CTol)(μ-H)2 (4). Complex 4 crystallizes in the centrosymmetric monoclinic space group P21/n with a = 12.531 (3) A?, b = 11.007 (2) A?, c = 21.733 (4) A?, β = 105.78(2)°, V = 2884.6 (11) A?3, and Z = 4. Diffraction data (Mo Kα, 2θ = 4-45°) were collected on a Syntex P21 automated diffractometer, and the structure was refined to RF = 6.2% for 3014 data with |Fo| > 3.0σ(|Fo|). The molecule contains a triangular triosmium core (Os(1)-Os(2) = 2.912 (1) A?, Os(2)-Os(3) = 2.875 (1) A?, Os(3)-Os(1) = 2.835 (1) A?) in which the two longer distances are believed to be associated with bridging hydride ligands; in addition, the triosmium system is capped by an asymmetrically triply bridging μ3-CTol ligand (Os(1)-C(06) = 2.184 (20) A?, Os(2)-C(06) = 2.051 (19) A?, Os(3)-C(06) = 2.025 (20) A?) and Os(1) is linked to a pendant CpW(CO)3 fragment (Os(1)-W = 3.097 (1) A?). In refluxing toluene complex 4 eliminates CpW(CO)3H and reacts with H2 or CO to form H3Os3(CO)9(μ3-CTol) (5) or HOs3(CO)10(μ3-CTol) (6), respectively. The related reaction of 4 with CpW(CO)2(CTol) provides CpWOs3(CO)10(μ3-CTol)2H (3), which implicates 4 as an intermediate in the previous synthesis of 3. The reaction of CpW(CO)2(CTol) with D2Os3(CO)10 leads to a partially modified product distribution that strongly favors the acyl complex (1-d2) at the expense of deuterated 3 + 4. This is interpreted in terms of linked pathways for forming 1 and 4 but a separate pathway for forming 2.
Degenerate framework rearrangement in a capped-square-pyramidal metal-carbon cluster and its conversion to a capped-trigonal-bipyramidal cluster. Crystal structures of (η5-C5H5)WOs3(CO) 10(μ3-CC6H4CH3) 2H and (η5-C ...
Park, Joon T.,Shapley, John R.,Churchill, Melvyn Rowen,Bueno, Clifford
, p. 4476 - 4486 (2008/10/08)
Full title: Degenerate framework rearrangement in a capped-square-pyramidal metal-carbon cluster and its conversion to a capped-trigonal-bipyramidal cluster. Crystal structures of (η5-C5H5)WOs3(CO) 10(μ3-CC6H4CH3) 2H and (η5-C5H5)WOs3(CO) 9(μ3-CC6H4CH3) 2H. The compound CpWOs3(CO)10(μ3-CTol)H (1) (Cp = η5-C5H5; Tol = p-C6H4CH3) is one of the products (together with 1 equiv of CpW(CO)3H) from the reaction of H2Os3(CO)10 and CpW(CO)2(CTol). Variable-temperature 1H and 13C NMR spectra of CpWOs3(CO)10(μ3-CTol)2H show that the compound in solution undergoes a degenerate framework rearrangement that interchanges the two alkylidyne moieties. This can be interpreted as breaking and making hydrogen-bridged metal-metal bonds. In refluxing toluene CpWOs3(CO)10(μ3-CTol)2H is converted to CpWOs3(CO)9(μ3-CTol)2H (2) by loss of a carbonyl ligand. The latter has been isolated as a crystalline solid and has been characterized by spectroscopic (infrared, mass, 1H and 13C NMR) data. Molecular structures of both tetrametallic dialkylidyne complexes have been determined by single-crystal X-ray diffraction studies. Crystals of CpWOs3(CO)10(μ3-CTol)2H belong to the monoclinic space group P21/n (C2h5, No. 14) with a = 10.610 (4) A?, b = 16.000 (3) A?, c = 19.394 (6) A?, β = 104.33 (2)°, V = 3189 (2) A?3, and ρ(calcd) = 2.72 g cm-3 for Z = 4 and molecular weight 1307. Diffraction data were collected on a Syntex P21 automated four-circle diffractometer using Mo Kα radiation, and the structure was refined to RF = 7.1% and RwF = 5.1% for all 3001 reflections with 2θ = 3.0-40°. The four metal atoms adopt a butterfly configuration. The dihedral angle between Os(1)-Os(2)-W and Os(3)-Os(2)-W planes is 98.7°. The molecule contains two μ3-CTol ligands. One occupies a normal position on the outside of the Os(2)-Os(3)-W triangle; the other takes up an unusual position, bridging the hinge tungsten atom and the two wing-tips of the butterfly. The WOs3(μ3-C)2 fragment defines a capped square pyramid (base defined by Os(1)-Os(2)-Os(3)-C(11) and principal apex by W). CpWOs3(CO)9(μ3-CTol)2H crystallizes in the monoclinic space group P21/n (C2h, No. 14) with a = 19.067 (3) A?, b = 16.828 (3) A?, c = 19.947 (3) A?, β = 98.62 (1)°, V = 6327 (2) A?3, and ρ(calcd) = 2.68 g cm-3 for Z = 8 and molecular weight 1279. Diffraction data were collected as described above, and the structure was refined to RF = 5.4% and RwF = 5.1% for 6169 reflections with 2θ = 3.5-45° and I > 1.5σ(I). There are two equivalent molecules (A and B) in the crystallographic asymmetric unit. The tetrametallic cluster adopts a tetrahedral geometry and contains two μ3-CTol ligands, which are located in almost equivalent environments on opposing sides of the pseudo plane of symmetry. Os(1), a unique osmium atom, and W are bonded to both alkylidyne fragments, and the Os(1)-W vector is almost coincident with the pseudo plane of symmetry. Molecules A and B have similar stereochemistry with the exception of the conformation of the carbonyl ligands surrounding Os(3). A terminal hydride on the tungsten atom was located from a difference-Fourier synthesis only in molecule B.
