含硅铁键环状化合物[Me2Si-η5-C5H4Fe(CO)(PPh3)][Me2Si-η5-C5H4Fe- (CO)2－n(PPh3)n] (n＝0或1)的合成与结构

鉴于含硅-过渡金属键化合物作为催化剂具有重要的应用价值, 在我们最近发现的化合物(η⁵,η⁵-C₅H₄Me₂SiSi-Me₂C₅H₄)Fe₂(CO)₄ (1)的硅硅键和铁铁键复分解重排反应可以有效地合成含有两个硅铁键的环状化合物[Me₂Si-η⁵-C₅H₄- Fe(CO)₂]₂ (2)的基础上, 对该硅铁键环状化合物的三苯基膦取代衍生物[Me₂Si-η⁵-C₅H₄-Fe(CO)(PPh₃)][Me₂Si-η⁵-C₅H₄Fe(CO)_2－n(PPh₃)_n] (3: n＝0, 5: n＝1)的合成方法进行了研究. 发现化合物1在三苯基膦存在下的复分解重排反应是合成单三苯基膦取代产物3的最好方法; 而双三苯基膦取代化合物5则可通过光照条件下2与三苯基膦发生羰基取代反应而得到, 产物中含有的顺反异构体可利用制备薄层色谱法分离. 利用X射线衍射法测定了化合物3的分子结构, 考察了三苯基膦配体的存在对分子结构的影响以及三苯基膦与铁形成的配位键的稳定性.     

Synthesen und Kristallstrukturen von [(t-Bu4Sb4)Fe(CO)4], [(t-Bu4Sb4)Mo(CO)5] und [(t-Bu3Sb4)Mo(η5-C5Me5)(CO)3]

Syntheses and Crystal Structures of [( t -Bu₄Sb₄)Fe(CO)₄], [( t -Bu₄Sb₄)Mo(CO)₅], and [( t -Bu₃Sb₄)Mo(η⁵-C₅Me₅)(CO)₃] t-Bu₄Sb₄ reacts with Fe₂(CO)₉ to form [(t-Bu₄Sb₄)Fe(CO)₄] ( 1 ). [(t-Bu₄Sb₄)Mo(CO)₅] ( 2 ) is formed from (thf)Mo(CO)₅ and t-Bu₄Sb₄. [(t-Bu₃Sb₄)Mo(η⁵-C₅Me₅)(CO)₃] ( 3 ) is a product of the reaction of t-Bu₄Sb₄ with [(η⁵-C₅Me₅)Mo(CO)₃]₂. The crystal structures of 1–3 are reported.     

Metal dimers as catalysts : III. The reaction between Fe(CO)5, and group V donor ligands in the presence of [(η5-C5H4R)Fe(CO)222]2 (R  H,Me) and [(η5-C5Me5)Fe(CO)2]2 as catalyst

The reaction between Fe(CO)₅, and group V donor ligands L, (L  PPh₃, AsPh₃, SbPh₃, PMePh₂, PMe₂Ph, Asme₂Ph, P(C₆H₁₁)₃, P(n-Bu)₃, P(i-Bu)₃, P(OPh)₃, P(OEt)₃, P(OMe)₃) in the presence of [(η⁵-C₅Me₅Fe(CO)₂]₂ (R  H, Me) or [(η⁵-C₅Me₅)Fe(CO)₂]₂ as catalyst in refluxing toluene, rapidly gives the complexes Fe(CO)₄L in yields > 85%. The reaction rate is essentially independent of the nature of L for [(η₅-C₅Me₅)Fe(CO)₂]₂ as catalyst. For the other catalysts, the rate is influenced predominantly by the steric properties of L. These results are interpreted in terms of the interaction between the catalyst and the ligand L to give derivatives of the type (η⁵-C₅H₄R)₂Fe₂,(CO)₃,(L). These derivatives were also found to catalyse the reaction between Fe(CO)₅, and L. The complexes [(η-C₅H₄R)Fe(CO)₂]₂ (R  H, Me) and [(η⁵-C₅Me₅)Fe(CO)₂]₂ also catalyse the reaction between Mn₂(CO)₁₀ and PPh₃ to give Mn₂(CO)₈- PPh₃)₂ in > 80% yield.     

Synthesis and Crystal Structure of [(n5-C5Me5)2Fe2S4](PF6)2

Abstract

The title compound was synthesized by electrochemical oxidation of (η⁵-C₅Me₅)₂Fe₂S₄ and its X-ray crystal structure was determined. A μ₂-S₂ ligand is converted to μ₂-η²-s₂ ligand by the oxidation.     

(Eta-C5H4R)Fe(CO)2X], X = Cl, Br, I, NO3, CO2Me and [(eta-C5H4R)Fe(CO)3]+, R = (CH2)nCO2Me (n = 0-2), and CO2CH2CH2OH: a new group of CO-releasing molecules

A new group of CO-releasing molecules, CO-RMs, based on cyclopentadienyl iron carbonyls have been identified. X-Ray structures have been determined for [(eta-C(5)H(4)CO(2)Me)Fe(CO)(2)X], X = Cl, Br, I, NO(3), CO(2)Me, [(eta-C(5)H(4)CO(2)Me)Fe(CO)(2)](2), [(eta-C(5)H(4)CO(2)CH(2)CH(2)OH)Fe(CO)(2)](2) and [(eta-C(5)H(4)CO(2)Me)Fe(CO)(3)][FeCl(4)]. Half-lives for CO release, (1)H, (13)C, and (17)OC NMR and IR spectra have been determined along with some biological data for these compounds, [(eta-C(5)H(4)CO(2)CH(2)CH(2)OH)Fe(CO)(3)](+) and [[eta-C(5)H(4)(CH(2))(n)CO(2)Me]Fe(CO)(3)](+), n = 1, 2. More specifically, cytotoxicity assays and inhibition of nitrite formation in stimulated RAW264.7 macrophages are reported for most of the compounds analyzed. [(eta-C(5)H(5))Fe(CO)(2)X], X = Cl, Br, I, were also examined for comparison. Correlations between the half-lives for CO release and spectroscopic parameters are found within each group of compounds, but not between the groups.     

Host-guest complexes [(H4L)(SiF6)2-4H2O] and [(H4L)(GeF6)2 4H2O] (L =meso-5,7,7,12,12,14-hexamethyl-1,4,8,11-tetraazacyclotetradecane)

Synthesis and X-ray structure analysis of host-guest complexes [(H₄L)(SiF₆)₂-4H₂O] (I) and [(H₄L)(GeF₆)₂-4H₂O] (II) are reported (L = meso-5,7,7,12,12,14-hexamethyl-l,4,8,11-tetraazacyclo-tetradecane). The crystals of both compounds are triclinic with close unit cell parameters. I: a = 9.576(3), b= 9.217(3), c= 8.334(2) å, α= 105.66(2), Ω= 83.68(2), α = 105.38(2)? II: a= 9.627(3), b = 9.358(3), c.= 8.497(4) A, a= 106.02(2), Ω = 83.74(2), α= 106.06(2)?. The structural units of the crystals are the (H₄L)⁴⁺ cations, the hexafluorosilicate (or hexafluowgemanate) anions, and the water molecules linked by a system of H bonds. The macrocycle in the complexes has C₁ symmetry. In the inorganic anions, the silicon as well as germanium atom is surrounded by an octahedron of six fluorine atoms.

     

Synthesis and structure of trinuclear clusters (Et4N)2[(μ3-Se)]Fe3(CO)9, [(μ-H)2Fe3(μ3-Se)(CO)9], and [(μ3-Se)FeMo2(η5-C5H5)2(CO)7]

The cluster anion [Fe₃(μ₃-Se)(CO)₉]^2- (I) was isolated as a salt (Et₄N)₂[I] by the reaction of Fe(CO)₅ with Na₂Se in isopropanol. The protonated form, (μ-H)₂Fe₃(μ₃-Se)(CO)₉ (II), was obtained by acidifying the reaction mixture and used for the synthesis of the heterometallic cluster FeMo₂(μ₃-Se)(CO)₇Cp₂ (III), CP=η⁵-C₅H₅. The structure of I and III was established by X-ray diffraction analysis. Crystals I are monoclinic, a=14.210(3), b=11.547(3), c=19.831(2), Å, β=90.92(2)°, V_cell=3254(1) ų, space group P2/c, Z=4, d_calc=1.550 g/cm³, Syntex P2₁, λCuK_α, R(F)=0.1333 for 1264 F_hkl>6σ(F_hkl). Crystals III are monoclinic, a=20.440(5), b=12.771(3), c=16.342(4) Å, β=113.80(2)°, V_cell=3903(2) ų, space group P2₁/c, Z=8, d_calc=2.222 g/cm³, Syntex P2₁, λCuK_α, R(F)=0.0734 for 1116 F_hkl>4σ(F_hkl). The structure of II was inferred from the Mössbauer, IR, and¹H and⁷⁷Se NMR spectroscopy data.     

Synthese und Kristallstruktur von (C5H5)Mo(CO)3(AuPPh3) und [(C5H5)Mo(CO)2(AuPPh3)4]PF6

Synthesis and Crystal Structure of (C₅H₅)Mo(CO)₃(AuPPh₃) and [(C₅H₅)Mo(CO)₂(AuPPh₃)₄]PF₆ CpMo(CO)₃(AuPPh₃) is obtained by the reaction of Li[CpMo(CO)₃] with Ph₃PAuCl at ?95°C in CH₂Cl₂. It crystallizes in the monoclinic space group C2/c with a = 2625.1(7), b = 883.2(1), c = 2328.4(7) pm, β = 116.39(1)° und Z = 8. In the complex the AuPPh₃ group is coordinated to the CpMo(CO)₃ fragment with a Au? Mo bond of 271,0 pm. The Mo atom thus achieves a square pyramidal coordination with the center of the Cp ring in apical position. CpMo(CO)₃(AuPPh₃) reacts under uv irradiation with an excess of Ph₃PAuN₃ to afford the cluster cation [CpMo(CO)₂(AuPPh₃)₄]⁺. It crystallizes as [CpMo(CO)₂(AuPPh₃)₄]PF₆ · 2 CH₂Cl₂ in the orthorhombic space group P2₁2₁2₁ with a = 1553.9(1), b = 1793.8(2), c = 2809.8(7) pm und Z = 4. The five metal atoms form a trigonal bipyramidal cluster skeleton with the Mo atom in equatorial position. The Mo? Au distances range from 275.5 to 280.8 pm, and the Au? Au distances are between 281.2 and 285.6 pm.     

Synthese und Struktur von [(Ph3C6H2)Te]2, [(Ph3C6H2)Te(AuPPh3)2]PF6 und [(Ph3C6H2)TeAuI2]2

Synthesis and Structure of [(Ph₃C₆H₂)Te]₂, [(Ph₃C₆H₂)Te(AuPPh₃)₂]PF₆ and [(Ph₃C₆H₂)TeAuI₂]₂ [(2,4,6-Ph₃C₆H₂)Te]₂ reacts with Ph₃PAu⁺ to yield [2,4,6-Ph₃C₆H₂TeAuPPh₃₂]PF₆ which can be oxidized by I₂ to form the gold(III) complex [(2,4,6-Ph₃C₆H₂)TeAuI₂]₂. [(2,4,6-Ph₃C₆H₂)Te]₂ crystallizes in the monoclinic space group P2₁/c with a = 810.6(2); b = 2026.5(5); c = 2260.6(7) pm; β = 99.23(3)° and Z = 4. In the crystal structure the ditelluride exhibits a dihedral angle C11? Te1? Te2? C21 of 66.1(2)°. The distance Te1? Te2 is 269.45(6) pm. In the cation of the triclinic complex [(2,4,6-Ph₃C₆H₂)Te(AuPPh₃)₂]PF₆ (space group P1 ; a = 1197.4(3); b = 1457.2(4); c = 1680.0(6) pm; α = 84.69(3)°; β = 85.11(3)°; γ = 75.54(3)°; Z = 2) a pyramidal skeleton RTeAu₂ with distances Te? Au = 259.2(1) and 257.8(2) pm and Au? Au = 295.3(1) pm is present. [(2,4,6-Ph₃C₆H₂)TeAuI₂]₂ crystallizes in the triclinic space group P1 with a = 1086.3(3); b = 1462.9(6); c = 1654.2(2) pm; α = 85.25(2)°; β = 87.44(1)°; γ = 80.90(3)°; Z = 2. In the centrosymmetrical dinuclear complex [(2,4,6-Ph₃C₆H₂)TeAuI₂]₂ the Au atoms exhibit a square-planar coordination by two iodine atoms and two tellurolate ligands. The tellurolate ligands form symmetrical bridges with distances Te? Au = 260.0 pm. The distances Au? I are in the range of 260.3(1) and 263.7(1) pm.