Reaction between [Ru3(CO)10(μ-dppm)] (dppm = Ph2PCH2PPh2) and Te2(C6H4OEt-4)2: X-ray crystal structure of [Ru2(CO)6{μ-C6H4PPh(CH2)PPh}]

Treatment of [Ru₃(CO)₁₀(-dppm)] (1) with the ditelluride Te₂(C₆H₄OEt-4)₂ in refluxing toluene afforded the new aryltellurol bridged complex [Ru₂(CO)₄(-TeC₆H₄OEt-4)₂ (-dppm)] (2) together with three known complexes [Ru₄(CO)₈(-CO)(₄-Te)₂(-dppm)] (3), [Ru₂(CO)₆{-CH₂PPh(C₆H₄)PPh}] (4), and [Ru₂(CO)₆{-C₆H₄PPh(CH₂)PPh}] (5). All the four complexes were characterized by spectroscopic methods, including an X-ray structure determination for 5. Complex 5 crystallizes in the monoclinic space group P2₁/c with a = 13.650(2), b = 9.995(2), c = 18.929(3) Å, = 97.49(2)°, V = 2560.4(8) ų, and Z = 4. In this complex the two ruthenium atoms are bridged by the phosphino-phosphide ligand C₆H₄PPh(CH₂)PPh which is attached to one Ru by the C₆H₄ group and a P atom while to the other Ru by both the two P atoms. Both the ruthenium atoms show distorted octahedral geometry. The Ru—Ru bond length is 2.8719(7) Å.     

Regiospecific ligand addition to the donor–acceptor compound Ru2(CO)6(bpcd): syntheses and X-ray diffraction structures of Ru2(CO)5L(bpcd) and Ru2(CO)5L[μ-C=C(PPh2)C(O)CH2C}(O)](μ2-PPh2) (where L = PMe3 and tBuNC)

Thermal and Me₃NO-assisted activation of the donor–acceptor complex Ru₂(CO)₆(bpcd) (1) [where bpcd = 4,5-bis(diphenylphosphino)-4-cyclopenten-1,3-dione] with PMe₃ or ^tBuNC affords the mono-substituted complexes Ru₂(CO)₅L(bpcd), as a result of regiospecific ligand attack at the diphosphine-substituted ruthenium center. Solution NMR measurements (¹H and ³¹P) reveal that the PMe₃ derivative exists as a noninterconverting mixture of axial (3a) and equatorial (3e) isomers, with the only the equatorial isomer being observed for Ru₂(CO)₅(^tBuNC)(bpcd) (5). Near-UV irradiation of 1 in the presence of added ligand yields Ru₂(CO)₅L(bpcd), in addition to the known ₂-phosphido complex Ru²(CO)⁶ [-C=C(PPh₂)C(O)CH₂C(O)](₂-PPh₂) (2) and the corresponding phosphido-substituted complexes Ru²(CO)_5L[-{C =C(PPh₂)C(O)CH₂C}(O)]₂-PPh₂)[4 (L = PMe₃); 6 (L = ^tBuNC)]. As with compounds 3a, 3e, and 5, both 4 and 6 exhibit ligand attachment at the diphosphine-substituted ruthenium center. The molecular structures of 3e, 4, 5, and 6 were determined by X-ray crystallography. 3e, as the 1/2 C₆H₆ solvate, crystallizes in the monoclinic space group C2/c: a = 40.573(3) Å, b = 10.2663(9) Å, c = 18.347(1) Å, = 95.371(6)°, V = 7609(1) ų and Z = 8; 4, crystallizes in the monoclinic space group P2₁/n: a = 10.8241(8) Å, b = 18.074(1) Å, c = 19.194(1) Å, = 96.968(6)°, V = 3727.3(5) ų, and Z = 4; 5, as the 1/2CH₂Cl₂ solvate, crystallizes in the monoclinic space group C2/c: a = 40.955(3) Å, b = 9.7230(6) Å, c = 20.542(1) Å, = 106.596(5)°, V = 7839.2(9) ų, and Z = 8; 6, as the 1/2C₅H₁₂ solvate, crystallizes in the monoclinic space group P2₁/c: a = 21.773(2) Å, b = 10.907(3) Å, c = 18.744(4) Å, = 114.68(1)°, V = 4045(1) ų, and Z = 4. The site occupied by the PMe₃ and ^tBuNC ligands in these compounds is discussed relative to the steric size/electronic properties of the ancillary ligand and its interaction with the bpcd ligand.     

Crystal structure of trans-W2(CO)6(PPh2H)2(μ2-PPh2)2

The molecular structure of trans-W²(CO)₆(PPh²H)²(₂-PPh²)² was determined by X-ray diffraction analysis. The two tungsten centers, bridged by two diphenylphosphido ligands, are separated by 3.0667(6) Å with W–P–W angles of 77.10(5) and 77.08(5). Average tungsten–phosphorus bond distances are 2.461(17) and 2.4576(21) Å for bridging and terminal phosphorus groups, respectively, with a range of 0.037 Å for the former and 0.001 Å for the latter. The complex crystallizes in the monoclinic space group P2₁/c with a = 19.282(4) Å, b = 12.158(2) Å, c = 21.294(9) Å, = 92.821(4), and Z = 4.     

Alkyne insertion and coupling reactions of methyl propiolate with the heterometallic dimers CoRu(CO)7(μ-PPh2) and CoRu(CO)5[(Z)-Ph2PCH = CHPPh2](μ-PPh2): X-ray diffraction structures of CoRu(CO)4(μ-CO)[μ-PPh2C(O)CH(CCO2Me)C(O)CHC (CO2Me)] and CoRu(CO)3(μ-CO)[(Z)-Ph2PCH = CHPPh2][μ-PPh2C(O)C(CO2Me)CH]

The reaction of the terminal alkyne methyl propiolate with the heterometallic dimers CoRu(CO)₇(μ-PPh₂) (1) and CoRu(CO)₅[(Z)-Ph₂PCH=CHPPh₂](μ-PPh₂) (2) has been investigated at 65^°C in toluene. In the reaction of 1, chromatographic purification afforded a minor band, from which the two species RuCo(CO)₄(μ-CO)[μ-PPh₂C(O)CHC(CO₂Me)] and RuCo(CO)₄(μ-CO)[μ-PPh₂CHC(CO₂Me)] were observed by ¹H NMR spectroscopy, and one major band, whose ¹H NMR spectrum revealed the presence of multiple species. The identity of one of the compounds in the major component has been established as that of CoRu(CO)₄(μ-CO)[μ-PPh₂C(O)CH(CCO₂Me)C(O)CHC(CO₂Me)] (3) by X-ray diffraction analysis. The solid-state structure of 3 confirms the double insertion of CO and head-to-head coupling of the methyl propiolate that accompanies the formation of this product. Compound 3 crystallizes in the triclinic space group P-1, a = 8.4035(4), b = 9.6721(5), c = 17.678(1) Å, α = 94.135(2), β = 103.318(2), γ = 101.336(2)^°, V = 1360.5(1) ų, Z = 2, D _calc = 1.732 Mg/m³; R = 0.0300, R _w = 0.0760 for 8630 reflections with I > 2σ(I). The ruthenium-bound diphosphine ligand in 2 exerts a controlling influence on the reaction with added alkyne insomuch as only the mono-insertion product CoRu(CO)₃(μ-CO)[(Z)-Ph₂PCH=CHPPh₂][μ-PPh₂C(O)C(CO₂Me)CH] (4) is formed as a single regioisomer. The molecular structure of 4 was established by X-ray diffraction analysis and 4 was found to crystallize in the monoclinic space group P2₁/c, a = 19.483(7), b = 11.905(4), c = 20.131(7) Å, β = 110.455(6)^°, V = 4375(3) ų, Z = 4, D _calc = 1.466 Mg/m³; R = 0.0961, R _w = 0.1683 for 6262 reflections with I > 2σ(I). The reactivity of methyl propiolate with 1 and 2 is compared with the known reactivity that has been reported for other alkynes.     

PhPMe2 ligand substitution in the tetracobalt cluster Co4(CO)10(μ4-PPh)2: X-ray diffraction structure of Co4(CO)8(PPhMe2)2(μ4-PPh)2

The thermal substitution chemistry of the tetracobalt cluster Co₄(CO)₁₀(₄-PPh)₂ with the phosphine ligand PhPMe₂ (2.5 equiv) has been explored and found to afford the bis(phosphine)-substituted cluster Co₄(CO)₈(PPhMe₂)₂(₄-PPh)₂ as the major reaction product. The regiochemistry and stereoselectivity exhibited by the two phosphine ligands in Co₄(CO)₈(PPhMe₂)₂(₄-PPh)₂ have been unambiguously established by X-diffraction analysis as having a 1,3-cis orientation. Co₄(CO)₈(PPhMe₂)₂(₄-PPh)₂ crystallizes in the monoclinic space group P2₁/n,a=10.314(1) Å,b=18.051(3) Å,c=21.313(2) Å, =90.10(1)°,V=3968.0(8) ų,Z=4,d _calc=1.590 g cm^–3;R=0.051,R _w=0.042 for 4987 observed reflections withI>3(I). Generalizations concerning the stereochemical disposition of two P-ligands about the Co₄(CO)₈P₂(₄-PPh)₂ (where P=phosphine or phosphite) polyhedron are discussed with respect to the cone angle of the P-ligand and its steric interactions with the capping phenylphosphinidene group.     

Bridging and chelating diphosphine ligands in Ru3(μ-H)(μ-N=CPh2)(CO)8(P—P). X-ray diffraction structures of Ru3(μ-H)(μ-N=CPh2)(CO)8(dmpe) and Ru3(μ-H)(μ-N=CPh2)(CO)8(bpcd)

Treatment of the azavinylidene-bridged cluster Ru₃(-H)(-N=CPh₂)(CO)₁₀ (1) with the diphosphine ligand bis(dimethylphosphino)ethane (dmpe) gives Ru₃( -H)(-N=CPh₂)(CO)₈(dmpe) (2) in moderate yield, while the ligand 4,5-bis(diphenylphosphino)-4-cyclopenten-1,3-dione (bpcd) reacts with Ru₃( -H)(-N=CPh₂)(CO)₁₀ in the presence of Me₃NO to furnish Ru₃( -H)(-N=CPh₂)(CO)₈(bpcd) (3) in low yield. Each new cluster has been isolated and characterized in solution by IR and NMR (¹H and ³¹P) spectroscopies, and the coordination mode exhibited by the ancillary diphosphine ligand in 2 and 3 has been established by X-ray crystallography. Ru₃( -H)(-N=CPh₂)(CO)₈(dmpe) crystallizes in the monoclinic space group P2(1)/c, a = 10.791(1) Å, b = 16.377(1) Å, c = 18.148(1) Å, = 96.675(2)°, V = 3185.3(4) ų, Z = 4, D _cacl = 1.791 Mg/m³; R = 0.0360, R _w = 0.0866 for 7522 observed reflections with I > 2(I). Ru₃(-H)(-N=CPh₂)(CO)₈(bpcd) crystallizes, as the CH₂Cl₂ solvate, in the triclinic space group , a = 11.956(1) Å, b = 14.228(1) Å, c = 31.409(3) Å, = 89.377(2)°, = 79.344(2)°, = 77.235(2)°, V = 5118.4(8) ų, Z = 2, D _calc = 1.670 Mg/m³; R = 0.0557, R _w = 0.1069 for 10977 observed reflections with I > 2(I). The structural details of clusters 2 and 3 are contrasted with Ru₃(-H)(-N=CPh₂)(CO)₇(-dppm)(-dppm), which is the only known structurally characterized phosphine-substituted cluster of this genre.     

X-ray diffraction structure of the phosphido-bridged mixed-metal cluster Fe2(CO)6(μ3-PPh)2Pt(dppe)

Treatment of Fe₂(CO)₆(₂-PPhH)₂ with BuLi (2 equiv.), followed by the addition of PtCl₂ (dppe), affords the phosphido-bridged cluster Fe₂(CO)₆(₃-PPh)₂Pt(dppe). The Fe₂Pt cluster was isolated and characterized in solution by IR and ³¹P NMR spectroscopy, and the molecular structure of Fe₂(CO)₆(₃-PPh)₂Pt(dppe) determined by X-ray diffraction analysis. Fe₂(CO)₆(₃-PPh)₂Pt(dppe) crystallizes in the orthorhombic space group P_bca, a = 17.539(3) Å, b = 21.490(2) Å, c = 22.959(3) Å, V = 8653.5(18) ų, Z = 8, d_calc = 1.670 g cm^–3; R = 0.0644, R_w = 0.0389 for 5040 observed reflections with I > 3(I).     

Reinvestigation of the reaction of [Ru3(CO)12] with 2-mercaptobenzothiazole: X-ray structure of [(μ-H)2Ru3 (μ-η2-C7H4NS2)(μ3-η2-C7H4NS2)(CO)7]

Treatment of Ru₃(CO)₁₂ with 2-mercaptobenzothiazole at 68°C gave the known compound [(-H)Ru₃(₃-²-C₇H₄NS₂)(CO)₉] 1 and the new compound [(-H)₂Ru₃(-²-C ₇H₄NS₂) (₃-²-C₇H₄NS₂)(CO)₇] 2 in 15 and 10% yields respectively. Compound 2 has been characterized by elemental analysis, infrared, ¹H NMR and mass spectroscopic data together with single crystal X-ray crystallography. It crystallizes in the monoclinic space group C2/c with a = 31.662(6), b = 14.577(3), c = 11.602(2) Å, = 104.15(3)°, Z = 8, and V = 5192.4(2) ų. The compound consists of a Ru₃ triangle with three different Ru-Ru bond lengths [2.75264, 2.79084, 2.97604 Å] and the two 2-mercaptobenzothiazole ligands are differently attached to the metal atoms. Compound 2 is also obtained by the reaction of 1 with excess 2-mercaptobenzothiazole at 68°C.     

Site-selective ligand substitution in CoRu(CO)7(μ-PPh2) using (Z)-Ph2PCH=CHPPh2 and reactivity of DMAD with CoRu(CO)5[(Z)-Ph2PCH=CHPPh2](μ-PPh2). X-ray structures of CoRu(CO)5[(Z)-Ph2PCH=CHPPh2](μ-PPh2) and CoRu(CO)3(μ-CO)[(Z)-Ph2PCH=CHPPh2] [μ, η3-Ph2PC(CO2Me)C(CO2Me)]

The heterometallic complex CoRu(CO)₇(μ-PPh₂) (1) reacts with the diphosphine ligand (Z)-Ph₂PCH=CHPPh₂ under both thermolysis and Me₃NO activation to furnish CoRu(CO)₅[(Z)-Ph₂PCH=CHPPh₂](μ-PPh₂) (2) in good yield. Treatment of 2 with dimethyl acetylenedicarboxylate (DMAD) at elevated temperature leads to the formal insertion of the DMAD ligand into the Co–phosphido bond and formation of the metallocyclic compound CoRu(CO)₃(μ-CO)[(Z)-Ph₂PCH=CHPPh₂][μ,η³-Ph₂PC(CO₂Me)C(CO₂Me)] (3) that contains a 5e^? alkenylphosphine moiety. These new CoRu compounds have been isolated by chromatography and fully characterized in solution by IR and NMR (¹H and ³¹P) spectroscopies, and the solid-state structures of both 2 and 3 have been determined by X-ray diffraction analysis. CoRu(CO)₅[(Z)-Ph₂PCH=CHPPh₂](μ-PPh₂) crystallizes in the monoclinic space group P2 ₁/n, a = 11.493(8), b = 20.24(1), c = 17.04(1) Å, β = 91.03(1)°, V = 3964(5) ų, Z = 4, D _calc = 1.477 Mg/m³; R = 0.0475, R _w = 0.1054 for 5120 observed reflections with I > 2σ (I). CoRu(CO)₃(μ-CO)(Z)-Ph₂PCH=CHPPh₂][μ,η³-Ph₂PC(CO₂Me)C(CO₂Me)], as the CH₂Cl₂ solvate, crystallizes in monoclinic space group P2 ₁/c, a = 17.0307(9) Å, b = 11.2124(6) Å, c = 24.083(1) Å, β = 97.755(1)°, V = 4556.8(4) ų, Z = 4, D _calc = 1.579 Mg/m³; R = 0.0379, R _w = 0.0609 for 10774 observed reflections with I > 2σ(I). The regioselective coordination of the (Z)-Ph₂PCH=CHPPh₂ ligand to the two equatorial sites of the ruthenium center in 2 and the presence of the metallocyclic alkenylphosphine ligand in 3 are confirmed by the structural studies. The regiochemistry found in the coordination of (Z)-Ph₂PCH=CHPPh₂ to 1 is contrasted with the related diphosphine ligands bma and bpcd, while the DMAD insertion reactivity with 2 is discussed relative to alkyne reactions reported for the parent compound CoRu(CO)₇(μ-PPh₂).     

Diphosphine ligand substitution in H4Ru4(CO)12: X-ray diffraction structures and reactivity studies of the cluster compounds H4Ru4(CO)10(P–P) [where P–P–(Z)–Ph2PCH–CHPPh2, bpcd]

The tetraruthenium cluster H₄Ru₄(CO)₁₂ (1) has been studied for its reactivity with the unsaturated diphosphine ligands (Z)–Ph₂PCH–CHPPh₂ and 4,5-bis(diphenylphosphino)-4-cyclopenten-1,3-dione (bpcd) under thermal, near-UV photolysis, and Me₃NO-assisted activation. All three cluster activation methods promote loss of CO and furnish the anticipated substitution products H₄Ru₄(CO)₁₀[(Z)–Ph₂PCH–CHPPh₂] (2) and H₄Ru₄(CO)₁₀(bpcd) (3) that possess a chelating diphosphine ligand. Clusters 2 and 3 have been characterized in solution by IR and NMR spectroscopies, and these data are discussed with respect to the crystallographically determined structure for both new cluster compounds. The ³¹P NMR spectral data and the solid-state structures confirm the presence of a chelating diphosphine ligand in clusters 2 and 3. Cluster 2 crystallizes in the monoclinic space P2₁/c, a=11.768(6) ?, b=18.521(9) ?, c=20.48(1) ?, β=102.291(8)°, V=4361(4) A³, Z=4, and d _calc=1.726 Mg/m³; R=0.0225, R _w=0.0491 for 6798 reflections with I > 2σ(I). The four bridging hydrides were located in H₄Ru₄(CO)₁₀[(Z)–Ph₂PCH–CHPPh₂] and their adopted positions are discussed relative to the solution ¹H NMR spectrum. H₄Ru₄(CO)₁₀(bpcd) crystallizes in the orthorhombic space Pbca, a=19.072(3) ?, b=20.169(3) ?, c=22.774(3) ?, V=8760(2) A³, Z=8, and d _calc=1.870 Mg/m³; R=0.0428, R _w=0.0896 for 10296 reflections with I > 2σ(I). Sealed NMR tubes containing clusters 2 and 3 were found to be exceeding stable towards near-UV light and temperatures up to ca. 125 °C. The surprisingly robust behavior of 2 and 3 is contrasted with the related cluster Ru₃(CO)₁₀(bpcd) that undergoes fragmentation to the donor-acceptor compound Ru₂(CO)₆(bpcd) and the phosphido-bridged compound Ru₂(CO)₆(μ–PPh₂)[μ–C–C(PPh₂)C(O)CH₂C(O)] under mild conditions. The electrochemical properties of each substituted cluster have been investigated by cyclic voltammetry, and our findings are discussed with respect to the reported electrochemical data on the parent cluster H₄Ru₄(CO)₁₂.

Formation of a samarium alkoxide–aryloxide complex containing a novel butterfly framework: X-ray crystal structures of Sm4(μ3-O-i-Pr)3(μ2-O-i-Pr)4(O-i-Pr)2(O-2,6-i-Pr2C6H3)3(THF) and [Ti(O-i-Pr)2(O-2,6-i-Pr2C6H3) (μ-O-i-Pr)]2

Reaction of a 1:1 mixture of Sm[N(SiMe₃)₂]₃ and Ti(O-i-Pr)₄ with three equivalents of 2,6-di-iso-propylphenol, followed by crystallization from hexane/THF, leads to isolation of the tetranuclear samarium alkoxide Sm₄(₃-O-i-Pr)₃(₂-O-i-Pr)₄(O-i-Pr)₂(O-2,6-i-Pr₂C₆H₃)₃(THF) (1), in addition to the dimeric titanium alkoxide [Ti(O-i-Pr)₂(O-2,6-i-Pr₂C₆H₃)(-O-i-Pr)]₂ (2). 1 crystallizes in the space group while 2 crystallizes in space group P2₁/c. Cell parameters for 1: a = 15.928(6), b = 17.677(7), c = 18.99(1) Å, = 113.24(3), = 94.99(4), = 109.59(2)°, V = 4477(4) ų, D _calc = 1.350 Mg/m³, and Z = 2. Cell parameters for 2: a = 25.336(2), b = 12.082(1), c = 15.570(2) Å, = 96.510(8)°, V = 4735.4(8) ų, D _calc = 1.129 mg/m³, and Z = 4.     

Reaction of bis(dimethoxyphosphino)dimethylhydrazine (dmpdmh) with Ru3(CO)12: Evidence for facile ligand fragmentation in Ru3(CO)10(dmpdmh) to give Ru4(CO)12[μ-N(Me)N(Me)], Ru3(CO)11[P(OMe)3], and Ru3(CO)9[μ-P(OMe)3]

Thermolysis of the cluster Ru₃(CO)₁₂ with the bis(phosphanyl)hydrazine ligand (MeO)₂PN (Me)N(Me)P(OMe)₂ (dmpdmh) in toluene at 75°C furnishes the known clusters Ru₄(CO)₁₂ [-N(Me)N(Me)] (2) and Ru₃(CO)₁₁[P(OMe)₃] (3), in addition to the new cluster Ru₃ (CO)₁₀(dmpdmh) (1) and the phosphite-tethered cluster Ru₃(CO)₉[-P(OMe)₃] (4). The simple substitution product Ru₃(CO)₁₀(dmpdmh), a logical intermediate to clusters 2–4, was synthesized by treating Ru₃(CO)₁₂ with Me₃NO in CH₂Cl₂ at room temperature, and independent thermolysis reactions using cluster 1 was shown to yield clusters 2–4. The solid-state structure of clusters 2 and 4 were unequivocally established by X-ray diffraction analysis. Ru₄(CO)₁₂[-N(Me)N(Me)] crystallizes in the orthorhombic space group Pnna (#52), a = 12.913(1), b = 13.3238(6), c = 12.5690(8) Å, V = 2162.5(2) ų, Z = 4, and d _calc = 2.452 g/cm³. Ru₃(CO)₉[-P(OMe)₃] crystallizes in the triclinic space group P a = 9.586(1), b = 14.354(1), c = 14.997(2) Å, = 89.82(1)°, = 98.36(1)°, = 92.010(8)°, V = 2040.4(4) ų, Z = 4, and d _calc = 2.212 g/cm³. The coordination of the dimethylazo linkage to the four ruthenium atoms in 2 and the phosphorus atom and one of the oxygen atoms of the methoxy groups to the three ruthenium centers in 4 are confirmed by X-ray analysis.     

Reaction of ethyl diazoacetate with Co3(CO)9(μ3-CCl): Isolation and X-ray structures of Co3(CO)9(μ3-CCO2Et), Co3(CO)9(μ3-CCH2CO2Et), and [Co3(CO)9(μ3-CCHCO2Et)]2

The reaction between the tricobalt cluster Co₃(CO)₉(₃-CCl) (1) and AlCl₃, followed by treatment with ethyl diazoacetate, N₂CHCO₂Et, affords a complex mixture of products in low yields. Column chromatography has allowed the isolation of the four cluster compounds Co₃(CO)₉(₃-CH) (2), Co₃(CO)₉(₃-CCO₂Et) (3), Co₃(CO)₉(₃-CCH₂CO₂Et) (4), and [Co₃(CO)₉(₃-CCHCO₂Et)]₂ (5). Clusters 4 and 5 are new and have been fully characterized in solution by IR and ¹H NMR spectroscopy. The molecular structures of clusters 3–5 have also been determined by single-crystal X-ray diffraction analysis. Co₃(CO)₉(₃-CCO₂Et) crystallizes in the triclinic space group P , a = 8.8393(5), b = 14.727(1), c = 15.272(1) Å, = 93.361(6), = 105.509(5)°, = 100.336(6)°, V = 1872.6(2) ų, Z = 4, and d _calc = 1.823 g/cm³. Co₃(CO)₉(₃-CCH₂CO₂Et) crystallizes in the monoclinic space group P2₁/n, a = 9.3806(7), b = 9.2617(8), c = 22.455(2) Å, = 94.483(7)°, V = 1944.9(3) ų, Z = 4, and d _calc = 1.803 g/cm³. [Co₃(CO)₉(₃-CCHCO₂Et)]₂ crystallizes in the monoclinic space group C2/c, a = 21.585(2), b = 8.7977(7), c = 20.784(1) Å, = 104.807(6)°, V = 3815.8(5) ų, Z = 4, and d _calc = 1.835 g/cm³. Plausible pathways leading to the formation of clusters 2, 4, and 5 are discussed.     

Crystal Packing of Potentially Mesomorphic Azobenezene Derivatives R1–C6H4–N=N–C6H4–R2 (R1, R2 = CH3COO,C2H5O; CH2=C(CH3)COO,C2H5; C6H13COO,C2H5O)

Crystallography Reports - The structure and thermal properties of azobenzene derivatives R1–C6H4–N=N–C6H4–R2, where R1/R2 = CH3COO/C2H5O (I), CH2=C(CH3)COO/C2H5 (II), or...     

Crystal structure of [WI2(CO)2{P(OiPr)3}(η2-EtC2Et)]

[WI₂(CO)₂{P(OⁱPr)₃}(²-EtC₂Et)] crystallizes in the monoclinic space group P2₁/n, with a = 11.101(12), b = 16.272(18), c = 14.892(17) Å, = 93.27(1), Z = 4. The geometry can be considered to be pseudo-octahedral, with the 3-hexyne ligand occupying one site, with two iodo-groups, and the P(OⁱPr)₃ ligand completing the equational plane of ligands, with two trans-carbonyl groups occupying the axial sites.     

Crystal structure of {NH2C(NHC6H5)2}3[UO2(C2O4)2(NCS)] · 1.25H2O

Synthesis and X-ray diffraction study of {NH₂C(NHC₆H₅)₂}₃[UO₂(C₂O₄)₂(NCS)] · 1.25H₂O single crystals have been performed. This compound is crystallized in the orthorhombic system, with the unit-cell parameters a = 45.2646(8) Å, b = 57.7359(11) Å, c = 7.9244(3) Å, sp. gr. Fdd2, Z = 16, V = 20 709.6(10) ų, and R = 0.0477. The uranium-containing structural units of the crystals are one-core groups of the [UO₂(C₂O₄)₂(NCS)]^3? composition, belonging to the crystallochemical group AB ₂ ⁰¹ M ¹ (A = UO ₂ ⁺² , B ⁰¹ = C₂O ₄ ^2? , M ¹ = NCS^?) of uranyl complexes. The uranium-containing complexes are connected into a three-dimensional framework owing to the electrostatic interactions with the outer-sphere cations and a system of hydrogen bonds.     

Decarbonylation Reaction of [Os3(CO)10(μ-H)(μ-SN2C4H5)]: X-ray Structures of the Two Isomers of [Os3(CO)9(μ-H)(μ 3-η 2-SN2C4H5)]

Abstract  The thermal reaction of [Os₃(CO)₁₀(μ-H)(μ-SN₂C₄H₅)] (1) at 110 °C afforded the new compound [Os₃(CO)₉(μ-H)(μ ₃-η ²-SN₂C₄H₅)] (2) in 84% yield. Compound 2 exists as two isomers, which differ in the disposition of the bridging hydride ligand. Both of the isomers of 2 have been characterized by a combination of elemental analysis, infrared and ¹H NMR spectroscopic data together with single crystal X-ray crystallography. The isomers crystallize together in the triclinic space group P-1 with a = 10.4775(2), b = 13.3056(3), c = 15.0325(3) ?, α = 110.8890(10), β = 99.3880(10), γ = 96.1620(10)°, Z = 2 and V = 1900.31(7) ?³. Index Abstract  The synthesis and the molecular structures of the two isomers of [Os₃(CO)₉(μ-H)(μ ₃-η ²-SN₂C₄H₅)] are described. The isomers differ in the disposition of the hydride ligand.      

X-ray structure and redox chemistry of the heptacobalt cluster Co3(CO)9[μ3-CCO2CH2CCH{Co4(CO)10}]

The tetrahedrane cluster reacts with Co₄(CO)₁₂ to furnish the heptacobalt compound Co₃(CO)₉[₃-CCO₂CH₂CCH{Co₄(CO)₁₀}] in high yield. Substitution of the pendant alkyne group by the Co₄(CO)₁₀ moiety was ascertained by IR and ¹H NMR spectroscopies, and the solid-state structure of Co₃(CO)₉[₃-CCO₂CH₂CCH{Co₄(CO)₁₀}] was unequivocally determined by X-ray crystallography. Co₃(CO)₉[₃-CCO₃CH₃CCH{Co₄(CO)₁₀}] crystallizes in the monoclinic space group P2 ₁/n, a = 12.895(13) Å, b = 18.803(18) Å, c = 13.748(13) Å, = 97.27(2)°, V = 3307(6) ų, Z = 4, d _calc = 2.087 mg/m³; R = 0.0493, R _w = 0.0989 for 4310 observed reflections with I > 2(I). The X-ray structure confirms the presence of an intact tetrahedral Co₃ moiety and an alkyne-tethered Co₄ butterfly cluster moiety. The cyclic voltammetric properties of Co₃(CO)₉[₃-CCO₂CH₂CCH{Co₄(CO)₁₀}] were examined and three reduction waves were found. The first two reduction waves correspond to the regionally localized 0/1^– redox couples on the tetra- and tricobalt moieties, respectively, while the third redox process is assigned to the 1^–/2^– reduction associated with the tetracobalt residue. Both 0/1^– redox couples are reversible, while the 1^–/2^– reduction exhibits only quasi-reversible behavior. No evidence for electronic communication between the Co₃ and Co₄ portions of the complex was observed. Extended Hückel MO calculations support the site of the first reduction occurring solely on the tetracobalt moiety of this Co₇ cluster.     

Regiospecific CO substitution in (μ-H)Ru3(μ3− η3-CHCHCMe)(CO)9 by 4,5-bis(diphenylphosphino)-4-cyclopenten-1,3-dione(bpcd). X-ray structure of (μ-H)Ru3(μ3−η3-CHCHCMe)(CO)7(bpcd)⋅MeOH

The triruthenium cluster ( -H)Ru₃( ₃–³-CHCHCMe)(CO)₉ reacts with the diphosphine ligand 4,5-bis(diphenylphosphino)-4-cyclopenten-1,3-dione (bpcd) in the presence of Me₃NO to afford ( -H)Ru₃( ₃– ³-CHCHCMe)(CO)₇(bpcd) in moderate yield. This new cluster has been isolated and characterized in solution by IR and NMR (¹H, ³¹P) spectroscopies, and the solid-state structure has been established by X-ray crystallography. ( -H)Ru₃( ₃– ³-CHCHCMe)(CO)₇(bpcd) MeOH crystallizes in the triclinic space group P , a = 11.2426(8) Å, b = 11.7141(8) Å, c = 16.195(1) Å, = 102.041(5)°, = 95.128(5)°, = 102.553(6)°, V = 2008.4(3) ų, Z = 2, d _calc. = 1.733 g/cm³; R = 0.0488, R _w = 0.0546 for 2212 observed reflections with I > 3 (I). The X-ray structure reveals that the bpcd ligand is bound exclusively to the Ru₃ core at the ruthenium center coordinated by the terminal CH unit of the -allylic ₃– ³-CHCHCMe moiety.