Rh2(CO)4(μ-Cl)2和Rh4(μ-CO)3(CO)4的简正振动分析

金属簇合物具有独特的结构和成键方式。本文对铑簇合物的简正振动分析进行了研究。通过红外光谱用石蜡油糊涂KBr和聚乙烯窗口, 在Nicolet 200SXV FT-IR光谱上测定了Rh2(CO)4(μ-Cl)2的构型, 并使用分子振动全分析程序MVTA(Basic语言), 在PC机上进行计算。     

Synthesis and characterisation of novel selenium-containing clusters; crystal structures of [Ru4(μ4-Se)2(CO)8(μ-CO)3] and [Ru3(μ3-Se)2(CO)7(Ph2P(CH2)3PPh2)]

The compound [Ru₄(μ-Se)₂(CO)₈(μ3-CO)₃] (1), has been obtained in good yield by vacuum pyrolysis of [RU₃(CO)₁₂] with [Ph₂Se₂] at 185°C. Reaction of 1 with 1,3-bis(diphenylphosphino)propane at room temperature affords the novel cluster [RU₃(μ₃-Se)₂(CO)₇(Ph₂P(CH₂)₃PPh₂)] (2). The structures of 1 and 2 have been determined by an X-ray diffraction study.     

Synthesis and characterisation of hexanuclear ruthenium clusters containing a μ4-nitrene ligand. Crystal structures of [Ru6(CO)15(μ-CO)2(μ4NH)(μ-OMe)μ3-η2-N(H)C(O)OMe] and [Ru6(CO)16(μ-CO)2(μ4-NH)(μ-OMe)(μ-NCO)]

Two hexaruthenium carbonyl clusters [Ru₆(CO)₁₅(μ-CO)₂(μ₄-NH) (μ-OMe){μ₃-η²-N(H)C(O)OMe}] and [Ru₆(CO)₁₆(μ-CO)₂-(μ₄-NH)(μ-OMe)(μ-NCO)]2 have been isolated from the pyrolysis of H₂Ru₃(CO))₉NOCH₃, and single-crystal X-ray structure analysis shows that both 1 and 2 have a square planar arrangement of four ruthenium atoms capped by a μ₄-nitrene ligand, with two additional ruthenium atoms bridging two opposite RuRu edges of the square base to form a ‘boat’ form metal framework.     

The Reaction of Alkenes with Triangulo-Clusters [Pt3(μ-CO)3(PR3)3]

The reactions of the cluster complexes [Pt₃(-CO)₃L₃], where L=PPh₃ 1a, PPh₂Bz 1b and PCy₃ 1c, with activated mono-olefins have been studied under preparative and equilibrium conditions. At low temperature the olefins react quantitatively giving the adducts [Pt₃(-CO)₃L₃(olefin)] (olefin=trans-dicyanoethene, DCE 2a–2c, maleic anhydride, MA 3a–3c). The stereo-chemistry of these unstable clusters has been deduced from low temperature ³¹P, ¹³C, ¹⁹⁵Pt-NMR and I.R. spectra. At higher temperature these adducts in presence of excess of olefin convert quantitatively to stable mononuclear Pt(0) complexes [Pt(CO)L(olefin)] (olefin=DCE 4a–4c, MA 5a–5c, maleimide, MI 6a–6c and 1–4-naphthoquinone, NQ 7a, 7c).     

Electrochemical and Photochemical Conversion of [Ru3Ir(μ 3-H)(CO)13] into [Ru3Ir(μ-H)3(CO)12]

Electrochemical and photochemical properties of the tetrahedral cluster [Ru₃Ir( ₃-H)(CO)₁₃] were studied in order to prove whether the previously established thermal conversion of this cluster into the hydrogenated derivative [Ru₃Ir(-H)₃(CO)₁₂] also occurs by means of redox or photochemical activation. Two-electron reduction of [Ru₃Ir( ₃-H)(CO)₁₃] results in the loss of CO and concomitant formation of the dianion [Ru₃Ir( ₃-H)(CO)₁₂]^2–. The latter reduction product is stable in CH₂Cl₂ at low temperatures but becomes partly protonated above 283K into the anion [Ru₃Ir(-H)₂(CO)₁₂]^– by traces of water. The dianion [Ru₃Ir( ₃-H)(CO)₁₂]^2– is also the product of the electrochemical reduction of [Ru₃Ir(-H)₃(CO)₁₂] accompanied by the loss of H₂. Stepwise deprotonation of [Ru₃Ir(-H)₃(CO)₁₂] with Et₄NOH yields [Ru₃Ir(-H)₂(CO)₁₂]^– and [Ru₃Ir( ₃-H)(CO)₁₂]^2–. Reverse protonation of the anionic clusters can be achieved, e.g., with trifluoromethylsulfonic acid. Thus, the electrochemical conversion of [Ru₃Ir( ₃-H)(CO)₁₃] into [Ru₃Ir(-H)₃(CO)₁₂] is feasible, demanding separate two-electron reduction and protonation steps. Irradiation into the visible absorption band of [Ru₃Ir( ₃-H)(CO)₁₃] in hexane does not induce any significant photochemical conversion. Irradiation of this cluster in the presence of CO with _irr>340nm, however, triggers its efficient photofragmentation into reactive unsaturated ruthenium and iridium carbonyl fragments. These fragments are either stabilised by dissolved CO or undergo reclusterification to give homonuclear clusters. Most importantly, in H₂-saturated hexane, [Ru₃Ir( ₃-H)(CO)₁₃] converts selectively into the [Ru₃Ir(-H)₃(CO)₁₂] photoproduct. This conversion is particularly efficient at _irr >340nm.     

New triosmium–iridium clusters: Synthesis and molecular structure of [Os3Ir2(Cp1)2(μ-OH)(μ-CO)2(CO)8Cl] (1), [Os3IrCp1(μ-OH)(CO)10Cl] (2), [Os3IrCp1(μ-H)(μ-Cl)(η3,μ3-C5H2N(NH2)Br)(CO)9] (3) and [Os3IrCp1(μ-Cl)2(η2,μ3-C5H3N(NH)Br)(CO)7] (4)

The trinuclear osmium carbonyl cluster, [Os₃(CO)₁₀(MeCN)₂], is allowed to react with 1 equiv. of [IrCp¹Cl₂]₂ (Cp¹ = pentamethylcyclopentadiene) in refluxing dichloromethane to give two new osmium–iridium mixed-metal clusters, [Os₃Ir₂(Cp¹)₂(μ-OH)(μ-CO)₂(CO)₈Cl] (1) and [Os₃IrCp¹(μ-OH)(CO)₁₀Cl] (2), in moderate yields. In the presence of a pyridyl ligand, [C₅H₃N(NH₂)Br], however, the products isolated are different. Two osmium–iridium clusters with different coordination modes of the pyridyl ligand are afforded, [Os₃IrCp¹(μ-H)(μ-Cl)(η³,μ₃-C₅H₂N(NH₂)Br)(CO)₉] (3) and [Os₃IrCp¹(μ-Cl)₂ (η²,μ₃-C₅H₃N(NH)Br)(CO)₇] (4). All of the new compounds are characterized by conventional spectroscopic methods, and their structures are determined by single-crystal X-ray diffraction analysis.     

SYNTHESIS OF A DINUCLEAR YLID COMPLEX DERIVED FROM P(OPh)3: CRYSTAL STRUCTURES OF [Cp2Fe2(CO)2(μ-CO) (μ-CHP(OPh)3)+][BF4 −] AND [Cp2Fe2(CO)2 (μ-CO)(μ-CHPPh3)+][BF4 −]

Abstract

[Cp₂Fe₂(CO)₂(μ-CO)(μ-CHP(OPh)₃)⁺][BF^? ₄] crystallizes in the centrosymmetric monoclinic space group P2₁/n with a = 12.553(7) Å, b = 16.572(11) Å, c = 15.112(8) Å, β = 100.00(4)°, V = 3096(3) ų and D(calcd.) = 1.579 g/cm³ for Z = 4. The structure was refined to R(F) = 5.83% for 1972 reflections above 4σ(F). The cation contains two CpFe(CO) fragments linked via an iron—iron bond (Fe(1)—Fe(2) = 2.544(3)Å), a bridging carbonyl ligand (Fe(1)—C(4) = 1.918(1) Å, Fe(2)—C(4) = 1.946(12)Å) and a bridging CHP(OPh)₃ ligand (Fe(1)—C(1) = 1.980(9)Å, Fe(2)—C(1) = 1.989(8)Å). Distances within the μ-CHP(OPh)₃ moiety include a rather short carbon—phosphorus bond [C(1)—P(1) = 1.680(10)Å] and P—O bond lengths of 1.550(7)–1.579(6)Å. The crystal is stabilized by a network of F…H—C interactions involving the BF^? ₄ anion.

[Cp₂Fe₂(CO)₂(μ-CO)(μ-CHPPh₃)⁺][BF^? ₄], which differs from the previous compound only in having a μ-CHPPh₃ (rather than μ-CHP(OPh)₃) ligand, crystallizes in the centrosymmetric monoclinic space group P2₁/c with a = 11.248(5)Å, b = 13.855(5)Å, c = 18.920(7)Å, β = 96.25(3)°, V = 2931(2)ų and D(calcd.) = 1.559 g/cm³ for Z = 4. This structure was refined to R(F) = 4.66% for 1985 reflections above 4σ(F). Bond lengths within the dinuclear cation here include Fe(1)-Fe(2) = 2.529(2)Å, Fe(1)—C(3) = 1.904(9) Å and Fe(2)—C(3) = 1.911(8) Å (for the bridging CO ligand) and Fe(1)—C(1P) = 1.995(6) Å and Fe(2)—C(1P) = 1.981(7) Å (for the bridging CHPPh₃ ligand). Distances within the μ-CHPPh₃ ligand include a longer carbon—phosphorus bond [C(1P)—P(1) = 1.768(6)Å] and P(1)—C(phenyl) = 1.797(7)–1.815(8) Å.     

Synthesis and structural characterization of the first transition metal cluster containing a PPh2AuPPh3 ligand,Ir4(CO)8(μ-CO)3(PPh2AuPPh3), and its conversion into Ir4(CO)9(μ-CO)(μ-PPh2)(μ-AuPPh3)

Deprotonation of Ir₄(CO)₁₁PPh₂H (1) in the presence of [AuPPh₃][PF₆] yields the novel species Ir₄(CO)₁₁(PPh₂AuPPh₃) (2), which possesses a tetrahedral framework bearing a terminally bound PPh₂AuPPh₃ ligand. When heated in toluene, 2 is converted into the phosphido species Ir₄(CO)₁₀(μ-PPh₂)(μ-AuPPh₃).     

Diphosphine ligand chelation and bridging and regiospecific ortho metalation in the reaction of 4,5-bis(diphenylphosphino)-4-cyclopenten-1,3-dione (bpcd) with Ir4(CO)12: X-ray diffraction structures of Ir4(CO)7(μ-CO)3(bpcd), Ir4(CO)5(μ-CO)3(bpcd)(μ-bpcd), and HIr4(CO)4(μ-CO)3(bpcd)[μ-PhP(C6H4)CC(PPh2)C(O)CH2C(O)]

Me₃NO activation of the tetrairidium cluster Ir₄(CO)₁₂ (1) in presence of the diphosphine ligand 4,5-bis(diphenylphosphino)-4-cyclopenten-1,3-dione (bpcd) furnishes the bpcd-substituted clusters Ir₄(CO)₁₀(bpcd) (3) and Ir₄(CO)₈(bpcd)₂ (4) as the minor and major products, respectively. Cluster 3 has been isolated as the sole observable product from the reaction of [Ir₄(CO)₁₁Br][Et₄N] (2) with bpcd in presence of AgBF₄ at room temperature. Both 3 and 4 have been isolated and fully characterized in solution by spectroscopic methods. The solid-state structure of 3 reveals that the ancillary bpcd ligand is bound to a single iridium center, with chelating and bridging bpcd ligands found in the X-ray structure of cluster 4. Cluster 4 is unstable at room temperature and slowly loses CO to afford the hydride-bridged cluster HIr₄(CO)₄(μ-CO)₃(bpcd)[μ-PhP(C₆H₄)CC(PPh₂)C(O)CH₂C(O)] (5). Cluster 5 has been fully characterized in solution by IR and NMR spectroscopies, and the C–H bond activation attendant in the ortho metalation step is shown to occur regioselectively at one of the aryl groups associated with the bridging bpcd ligand. The redox properties of clusters 3–5 have been explored and the electrochemical behavior discussed with respect to extended Hückel MO calculations and related diphosphine-substituted cluster compounds prepared by our groups.     

The chemistry of hydridocarbonylferrates revisited: syntheses and structures of the new [H2Fe4(CO)12]2- and [HFe5(CO)14]3- anions, and the [Fe(DMF)4][Fe4(CO)12(μ5-η2-CO)(μ-H)]2 adduct containing an unprecedented isocarbonyl

The di-hydride di-anion [H(2)Fe(4)(CO)(12)](2-) has been quantitatively obtained by protonation of the previously reported mono-hydride tri-anion [HFe(4)(CO)(12)](3-) in DMSO and structurally characterised in its [NEt(4)](2)[H(2)Fe(4)(CO)(12)] salt. It shows some subtle but yet significant differences in the stereochemistry of the ligands in comparison to the heavier Ru(4) and Os(4) congeners. The study of the reactivity of these [H(4 -n)Fe(4)(CO)(12)](n-) (n = 2,3) species allowed the serendipitous isolation and structural characterization of the new pentanuclear [HFe(5)(CO)(14)](3-) mono-hydride tri-anion. Attempts to obtain the latter in better yields led to the discovery of intermolecular CO/H(-) mutual exchange reactions and isolation and structural characterization of the [Fe(DMF)(4)][Fe(4)(CO)(12)(μ(5)-η(2)-CO)(μ-H)](2)·0.5CH(2)Cl(2) and [M(+)][Fe(4)(CO)(12)(μ(4)-η(2)-CO)(μ-H)](-) (M = K, Cs) adducts, the former containing an unprecedented isocarbonyl group. The isolation of new tetranuclear and, above all, pentanuclear hydridocarbonylferrates indicates that it is possible to further expand the chemistry of homoleptic Fe carbonyl species.     

Synthesis, Characterization and Crystal Structure of [Co2Mo2(μ4-C2HPh)(μ-CO)4(CO)4(η5-C5H4C(O)Me)2]

The reaction of μ-alkyne-bridged dimolybdenum compound [Mo2(μ-C2HPh)(CO)4(η5-C5H4C(O)Me)2] 1 with Co2(CO)8 in refluxing toluene gave a new butterfly compound [Co2Mo2(μ4-C2HPh)(μ-CO)4(CO)4(η5-C5H4C(O)Me)2] 2 which was fully characterized by elemental analysis, IR, 1H NMR and X-ray single crystal diffraction techniques. 2 crystallized in monoclinic system, C30H20Co2Mo2O10, Mr=850.23, space group P21/a(#14), a=14.165(5), b=12.498(2), c=16.204(2)(A), β = 96.50(2)°, V = 2850(1)(A)3, Z = 4, Dc = 1.981 g cm-3, F(000)=1672, μ(MoKα)=20.41 cm-1, final R=0.030, Rw=0.039 for 4831 observable reflections with I>2σ(I). The structure contains a Co2Mo2 butterfly core, and each Mo-Co bond is spanned by an asymmetric semi-bridging carbonyl ligand.     

Synthesis,chemical, and electrochemical characterization of the [Ag13{μ3-Fe(CO)4}] n− (n = 3, 4, 5) cluster anions: X-Ray structural determination of [N(PPh3)2]3 [Ag12(μ12-Ag){μ3Fe(CO)4}8]1

The oxidation of the [Fe(CO)₄]^2– dianion with Ag⁺ salts occurs through a particularinner-sphere mechanism, which involves an intermediate cascade of silver clusters stabilized by Fe(CO)₄ ligands. The last detectable Ag-Fe cluster of the sequence is the [Ag₁₃{-Fe(CO)₄}₈]^3– trianion, which has been selectively obtained by using ca. 1.7 equivalents of Ag⁺ per mole of [Fe(CO)₄]^2–. The [Ag₁₃{-Fe(CO)₄}₈]^3–- trianion has been isolated in a crystalline state with several quaternary cations, and has been characterized by X-ray diffraction studies of its bis(triphenylphosphine)iminium salt. [N(PPh₃)₂]₃ [Ag₁₃{ ₃-Fe(CO)₄}₈]·2(CH₃)₂CO, monoclinic, space group P2₁ (No.4),a = 16.284(2) Å,b =18.767(5) Å,c = 25.905(4) Å, = 90.46(1)°,V = 7916(3) ų,Z = 2,R = 0.0324. The molecular structure of the anion consists of a centered cuboctahedron of silver atoms with the triangular faces capped by Fe(CO)₄ units. Chemical reduction of ( Ag₁₃{ ₃-Fe(CO)₄}₈]^3– affords the corresponding [Ag₁₃{ ₃-Fe(CO)₄)₈]^4–, which in turn gives [Ag₁₃{ ₃-Fe(CO)₄)₈]^5– and [Ag₆{ ₃-Fe(CO)₄}₄]^– upon further reduction. Electrochemical investigations confirm the reversibility of the [Ag₁₃{ ₃-Fe(CO)₄}₈]^3–/4– redox change. Furthermore, in spite of some electrode poisoning effects, evidence of the existence of the [Ag₁₃{ ₃-Fe(CO)₄}₈]^5– pentaanion was obtained. The yet structurally uncharacterized [Ag₆{ ₃-Fe(CO)₄)₄]^2– dianion is quantitatively obtained by reaction of [Fe(CO)₄]^2– with ca. 1.5 equivalents of Ag⁺ or by addition of one equivalent of Ag⁺ to solutions of the [Ag₅{Fe(CO)₄}₄]^3– trianion. All attempts to isolate its quaternary salts as crystalline materials failed owing to formation of amorphous insoluble precipitates. The above series of ₃-Fe(CO)₄ octa-capped cuboctahedral Ag₁₃ clusters can be envisioned as the Ag⁺ . Ag and Ag^– cryptates of the [Ag₁₂{}₃-Fe(CO)₄}₈]^4– cryptand. respectively.Dedicated to Prof L. F. Dahl on his 65th birthday.     

Synthesis and Structure of a Molybdenum–Cobalt Bimetallic Carbide Cluster [N(PPh3)2][Mo3Co3(μ6-C)(μ-CO)3(CO)15] Bearing Only Carbonyl Ligands

The reaction of a trinuclear cobalt cluster [ClCCo₃(CO)₉] with [Mo(CO)₃(CH₃CN)₃] gave a molybdenum–cobalt bimetallic cluster complex [Mo₃Co₃( ₆-C)(-CO)₃(CO)₁₅]^–. The cluster anion has a carbide-centered Mo₃Co₃ octahedral metal core, where the three molybdenum and three cobalt atoms are placed in facial positions. The six metal atoms are coordinated by only carbonyl ligands. The cluster is suitable for a model of heterogeneous desulfurization catalysts.     

Synthesis and Crystal Structure of[Co3(CO)9(μ3-C)C(O)OCH2]2

The title compound [Co3(CO)9(μ3-C)C(O)OCH2]2 was synthesized by the reaction of [Cl3CC(O)OCH2]2 with Co2(CO)8 at 40～50 ℃. Crystal data: C24H4O22Co6, Mr=997.88, monoclinic, space group P21/n(#14), a=9.330(2), b=15.197(4), c=11.783(4), β=91.16(2)°, V=1670.4(7) 3, Z=2, Dc=1.984 g/cm3, μ(MoKα)=30.01 cm-1, F(000)=972.00, T=293K, final R=0.045, Rw=0.051 for 1936 observed reflections with I＞2σ(I). The structure contains two centrosymmetric dimeric molecules in a unit cell, each of which has two tetrahedral skeletons (CCo3) connected through a C(O)OCH3CH2OC(O) bridge.     

Co_3(CO)_9(μ_3-PR)、Co_4(μ-CO)_2(CO)_8(μ_4-PR)_2和Co_2Fe(CO)_9(μ_3-PR)原子簇化合物合成与结构

本文合成了数个以有机磷作桥基配位体的同核钴和异核铁钴原子簇羰基化合物.通过元素分析、IR谱和~1H-NMR谱测定,确定三核钴簇合物Co_5(CO)_9-(μ_3-PR)和异核铁钴簇合物Co_2Fe(CO)_9(μ_3-PR)的分子骨架Co_3P和Co_2FeP具有三角锥构型,而四核钴簇合物Co_4(μ-CO)_2(CO)_8(μ_4-PR)_2的分子骨架Co_4P_2为八面体构型.     

An Improved Synthesis for Novel Hexaruthenium Cluster Compound Bearing Two Quadruply-Bridging CO Ligands: Synthesis, Characterization, and X-Ray Structural Analysis of Ru6(CO)12(μ3-H)(μ-CO) (μ4-η2-CO)2[η5-C5H4(SiMe3)]

The hexaruthenium cluster compound Ru₆(₃-H)(CO)₁₅[C₅H₄(SiMe₃)] (2), possessing two ₄-²-CO ligands and with the Ru[C₅H₄(SiMe₃)] fragment located at the apex of the central tetrahedral framework, was prepared in low yield by refluxing a toluene solution of C₅H₅(SiMe₃) with excess Ru₃(CO)₁₂. This unique complex was characterized by spectroscopic methods and by X-ray structural analysis. The possible mechanism leading to its formation is discussed.     

Reactions of carbonyl clusters with potentially tridentate thioethers: Crystal and molecular structures of [Os4(CO) 13([12]aneS3)] and [Ru6(CO)15(μ4-η2- CO)([12]aneS3)] [([12]aneS3) = {(CH2) 3S}3]

The reaction of [Os₃(CO)₁₂ with [12]aneS₃ ([12]aneS₃  {(CH₂)₃S}₃) in octane for 6 h, under reflux, led to isolation of two products [Os₃(CO)₁₁([12]aneS₃)] (1) and [Os₄(CO) ₁₃([12]aneS₃)] (2), while with [Ru₃(CO)₁₂] under similar conditions, in THF, a number of products were obtained, including [Ru₄(CO)₁₁([12]aneS₃)] (3), [Ru₅(CO)₁₃([12]aneS₃)] (4), and [Ru₆(CO)₁₆([12]aneS₃)] (5). An X-ray diffraction study of 2 shows that the macrocycle is coordinated to the ‘wingtips’ of an Os₄ butterfly through the two electron pairs on one sulphur atom, while in 5 all three sulphur atoms of the macrocycle coordinate to two of the Ru atoms in a spiked edge-bridged tetrahedral metal framework.     

Diphenylphosphine and diphenylphosphido derivatives of [Ru3(μ-H)(μ3-ampy)(CO)9] (Hampy = 2-amino-6-methylpyridine)

The reactions of [Ru₃(μ-H)(μ-ampy)(CO)₉] (1) (Hampy = 2-amino-6-methylpyridine) with one or two equivalents of PPh₂H lead to the complexes [Ru₃(μ-H)(μ₃-ampy)(CO)₈(PPh₂H)] (2) or [Ru₃(μ-H)(μ₃-ampy)(CO)₇(PPh₂H)₂] (3), in which the PPh₂H ligands are cis to the bridging NH fragment and cis to the hydride. Complex 2 can be transformed in refluxing THF into the phosphido-bridged derivative [Ru₃(μ₃-ampy)(μ-PPh₂)(μ-CO)₂(CO)₆] (4), which contains the PPh₂ ligand spanning one of the two RuRu edges unbridged by the amido moiety, and presents an extremely high ³¹P chemical shift of 386.9 ppm. Under similar conditions, complex 3 gives a mixture of two isomers of [Ru₃(μ-H)(μ₃-ampy)(μ-PPh₂)₂(CO)₆] in a 5:1 ratio; the major product (5) has a plane of symmetry, whereas the minor one (6) is asymmetric.