Mo(CO)3(NCMe)(PPh3)2: Synthesis, X-ray structure and evaluation of its catalytic activity for the homogeneous hydrogenation of olefins and their mixtures

The complex Mo(CO)₃(NCMe)(PPh₃)₂, was synthesized by the reaction of Mo(NCMe)₃(CO)₃ with two equivalents of PPh₃ and characterized by UV–Vis, IR, NMR and X-ray diffraction. This complex was used as a catalyst precursor for the hydrogenation of 1-hexene, styrene, cyclohexene and 2,3-dimethyl-1-butene and their mixtures under moderate conditions in homogeneous media. Under mild reaction conditions (T = 373 K, P = 60 atm), the substrates showed the following reactivity order: styrene > 1-hexene > cyclohexene > 2,3-dimethyl-1-butene. A quaternary equimolar mixture showed a different hydrogenation order: 1-hexene > cyclohexene > styrene > 2,3-dimethyl-1-butene; the presence of dibenzothiophene or mercury does not interfere with the activity of the catalyst.     

Four isomers from the oxidative addition of Me3SnH to Os(CO)2(PPh3)3 and the crystal structure of Os(SnMeI2)I(CO)2(PPh3)2, in which the pairs of CO and PPh3 ligands are mutually trans

Reaction between Os(CO)₂(PPh₃)₃ and Me₃SnH produces Os(SnMe₃)H(CO)₂(PPh₃)₂ (1). Multinuclear NMR studies of solutions of 1 reveal the presence of four geometrical isomers, the major one being that with mutually cis triphenylphosphine ligands and mutually trans CO ligands. Os(SnMe₃)H(CO)₂(PPh₃)₂ undergoes a redistribution reaction, at the trimethylstannyl ligand, when treated with Me₂SnCl₂ giving Os(SnMe₂Cl)H(CO)₂(PPh₃)₂ (2). Solutions of 2 again show the presence of four isomers but now the major isomer is that with mutually trans triphenylphosphine ligands and mutually cis CO ligands. The redistribution reaction of 1 with SnI₄ produces Os(SnMeI₂)H(CO)₂(PPh₃)₂ (3) which exists in solution as only one isomer, that with mutually trans triphenylphosphine ligands and mutually trans CO ligands. Treatment of 3 with I₂ cleaves the Os-H bond with retention of geometry giving Os(SnMeI₂)I(CO)₂(PPh₃)₂ (4). The crystal structure of 4 has been determined. No isomerization of the trans dicarbonyl complex 4 occurs when 4 is heated, instead there is a formal loss of “MeSnI” and formation of OsI₂(CO)₂(PPh₃)₂ (5).     

Mixed-metal cluster chemistry VI: Phosphine substitution at CpMoIr3(μ-CO)3(CO)8; X-ray crystal structure of CpMoIr3(μ-CO)3(CO)7(PPh3)

Reactions of CpMoIr₃(μ-CO)₃(CO)₈ (1) with stoichiometric amounts of phosphines afford the substitution products CpMoIr₃(μ-CO)₃(CO)_8−x (L)_x (L = PPh₃, x = 1 (2), 2 (3); L = PMe₃, x = 1 (4), 2 (5), 3 (6)) in fair to good yields (23–54%); the yields of both 3 and 6 are increased on reacting 1 with excess phosphine. Products 2–5 are fluxional in solution, with the interconverting isomers resolvable at low temperatures. A structural study of one isomer of 2 reveals that the three edges of an MoIr₂ face of the tetrahedral core are spanned by bridging carbonyls, and that the iridium-bound triphenyiphosphine ligates radially and the molybdenum-bound cyclopentadienyl coordinates axially with respect to this Molr₂ face. Information from this crystal structure, ³¹P NMR data (both solution and solid-state), and results with analogous tungsten—triiridium and tetrairidium clusters have been employed to suggest coordination geometries for the isomeric derivatives.     

Exchange of boryl ligand substituents in Os[B(OEt)2]Cl(CO)(PPh3)2

Reaction between Os[B(OEt)₂]Cl(CO)(PPh₃)₂ and 1,2-ethanediol in the presence of Me₃SiCl (1 equivalent) leads to the tethered boryl complex, Cl(CO)(PPh₃)₂ (1), in which one ethoxy substituent on the boryl ligand is exchanged with one hydroxy group of the 1,2-ethanediol leaving the other OH group available to coordinate to osmium, so giving a six coordinate complex. This formulation is confirmed by crystal structure determination. The same reactants, but with 2 equivalents of Me₃SiCl, lead to the yellow, coordinatively unsaturated complex, OsCl(CO)(PPh₃)₂ (2). Complex (2) adds CO to give OsCl(CO)₂ (PPh₃)₂ (3). Crystal structure determinations of 2 and 3 reveal a very marked difference in the Os-B distances found in the five coordinate complex 2 (2.043(4) Å) and the six coordinate complex 3 (2.179(7) Å). In a reaction similar to that used for forming 2 but with 1,3-propanediol replacing 1,2-ethanediol, the product is OsCl(CO)(PPh₃)₂ (4). The crystal structure for 4 is also reported.     

Synthesis and crystal structure of the novel trimanganese tetrathiolate incomplete cubane: [Mo(η-C5H5)2(H)CO][Mn3(CO)9(μ-SC6H5)4]

An unexpected trimanganese(I) tetrathiolate-bridged complex, [Mn₃(CO)₉(μ-SC₆H₅)₄]⁻, with an incomplete cubane structure, was obtained by thermal reaction of [Mn₂(CO)₁₀] with [Mo(η⁵-C₅H₅)₂(SC₆H₅)₂]. The structure, established by single-crystal X-ray diffraction studies, shows the cation, [Mo(η⁵-C₅H₅)₂(H)CO]⁺, directed towards the vacant site of the cubane structure. Possible routes by which the anion and the cation could be formed are discussed.     

Selenium-capped trimolybdenum and tritungsten carbonyl clusters [Se2M3(CO)10] (M = Mo, W)

A facile synthesis of the novel selenium-capped trimolybdenum and tritungsten ring carbonyl clusters [Se₂M₃(CO)₁₀]²⁻ (M = Mo, 1; W, 4) have been achieved. The selenium-capped trimolybdenum cluster compound [Et₄N]₂[Se₂Mo₃(CO)₁₀] ([Et₄N]₂[1]) can be obtained from the reaction of the trichromium cluster compound [Et₄N]₂[Se₂Cr₃(CO)₁₀] with 4 equiv. of Mo(CO)₆ in refluxing acetone. On the other hand, when [Et₄N]₂[Se₂Cr₃(CO)₁₀] reacted with 4 equiv. of W(CO)₆ in refluxing acetone, the planar cluster compound [Et₄N]₂[Se₂W₄(CO)₁₈] ([Et₄N]₂[3]) was isolated, which could further transform to the tritungsten cluster compound [Et₄N]₂[Se₂W₃(CO)₁₀] ([Et₄N]₂[4]) in good yield. Alternatively, clusters 1 and 4 could be formed from the reactions of the monosubstituted products [Et₄N]₂[Se₂Cr₂M(CO)₁₀] (M = Mo; W, [Et₄N]₂[2]) with 3 equiv. of M(CO)₆ in acetone, respectively. Complexes 1-4 are fully characterized by IR, ⁷⁷Se NMR spectroscopy, and single-crystal X-ray analysis. Clusters 1, 2, and 4 are isostructural and each display a trigonal bipyramidal structure with a homometallic M₃ ring (M = Mo, 1; W, 4) or a heterometallic Cr₂W ring that is further capped above and below by μ₃-Se atoms. Further, the intermediate planar complex 3 exhibits a Se₂W₂ square with each Se atom externally coordinated to one W(CO)₅ group. This paper describes a systematic route to a series of selenium-capped trimetallic carbonyl clusters and the formation and the structural features of the resultant clusters are discussed.     

New Bimetallic Ni–Rh Carbonyl Clusters: Synthesis and X-ray Structure of the [Ni7Rh3(CO)18]3?, [Ni3Rh3(CO)13]3? and [NiRh8(CO)19]2? Cluster Anions

The reaction of the [Ni₆(CO)₁₂]²⁻ dianion with [Rh(COD)Cl]₂ (COD = cyclooctadiene) in acetone affords a mixture of bimetallic Ni–Rh clusters, mainly consisting of the new [Ni₇Rh₃(CO)₁₈]³⁻ and [Ni₈Rh(CO)₁₈]³⁻ trianions. A study of the reactivity of [Ni₇Rh₃(CO)₁₈]³⁻ led to isolation of the new [Ni₃Rh₃(CO)₁₃]³⁻ and [NiRh₈(CO)₁₉]²⁻ anions. All these new bimetallic Ni–Rh carbonyl clusters have been isolated in the solid state as tetrasubstituted ammonium salts and have been characterised by elemental analysis, X-ray diffraction studies, ESI-MS and electrochemistry. The unit cell of the [NEt₄]₃[Ni₇Rh₃(CO)₁₈] salt contains two orientationally-disordered ν₂-tetrahedral [Ni₇Rh₃(CO)₁₈]³⁻ trianions with occupancy factors of 0.75 and 0.25. Besides, their inner Ni₃Rh₃ octahedral moieties show two cis sites purely occupied by Rh atoms, two trans sites purely occupied by Ni atoms and the remaining two cis sites are disordered Ni and Rh sites with respective occupancy fraction of 0.5. At difference from the parent [Ni₇Rh₃(CO)₁₈]³⁻, the octahedral [Ni₃Rh₃(CO)₁₃]³⁻ displays an ordered distribution of Ni and Rh atoms in two staggered triangles. The [NiRh₈(CO)₁₉]²⁻ dianion adopts an isomeric metal frame with respect to that of the [PtRh₈(CO)₁₉]²⁻ congener. As a fallout of this work, new high-yield synthesis of the known [Ni₆Rh₃(CO)₁₇]³⁻ and [Ni₆Rh₅(CO)₂₁]³⁻, as well as other currently-investigated bimetallic Ni–Rh clusters have been obtained.     

配合物[Ce(CH2=C(CH3)COO)2(NO3)(Bipy)]的合成及晶体结构

The new complex [Ce(CH₂=C(CH₃)COO)₂(NO₃)(Phen)]₂ was prepared in ethanol-aqueous solution with 8-hydroxyquinoline as the acidity regulator. Its crystal structure was determined by X-ray diffraction analysis. The title complex is triclinic, space group P1, a=1.00832(3)nm, b=1.02858(8)nm, c=1.12350(8)nm, α=113.9250(10)°, β=103.8210(10)°, γ=81.4650(10)°, V=1.03252(14)nm³, Z=1, D_c=1.700g·cm^-3, F(000)=522. The coordination number of Ce³⁺ is nine. CCDC: 211278.     

Bidentate phosphines of heteroarenes: effective stabilization of the Co2(CO)6 fragment by 4,6-bis(diphenylphosphino) dibenzofuran

Reaction of Co₂(CO)₈ with 4,6-bis(diphenylphosphino)dibenzofuran (1) in diethylether gives the dinuclear complex 4,6-bis(diphenylphosphino)dibenzofurandicobalthexacarbonyl (2). The solid state structures of 1 and 2 have been established by X-ray crystallography. Low temperature ¹³C-NMR spectroscopy was used to analyse 2 in solution.     

Synthesis and crystal structures of the chromium(II) and chromium(III) hexafluoroacetylacetonate complexes trans-Cr(hfac)2(thf)2 and Cr(hfac)3

Treatment of a tetrahydrofuran solution of CrCl₂(thf) with Na(hfac), hfac = 1,1,1,5,5,5-hexafluoroacetylacetonate, followed by crystallization from diethyl ether, affords the six-coordinate chromium(II) complex Cr(hfac)₂(thf)₂. The crystal structures of Cr(hfac)₂(thf)₂ and the chromium(III) complex Cr(hfac)₃ have been determined by single-crystal X-ray diffraction. Cr(hfac)₂(thf)₂ adopts a trans octahedral geometry, in which the Cr–O(hfac) and Cr–O(thf) distances are 1.936(3) and 2.019(6) Å, respectively. Cr(hfac)₃ is an octahedral compound with a Cr–O distance of 1.943(5) Å. Structural comparisons with related molecules are given.     

Structures, energy bands and conductivities of (Me3NEt)[Pd(dmit) 2]2 and (NEt4)[Pd(dmit) 2]2

The electrical conductive molecular crystals (Me₃NEt)[Pd(dmit) ₂]₂ and (NEt₄)[Pd (dmit) ₂]₂ (dmit = 4,5-dimercapto-1,3-dithiole-2-thione) have been prepared, and their crystal structures and conductivity-temperature curves have been determined. The fact that the conductivity at room temperature of (Me₃NEt)[Pd(dmit) ₂]₂ (σ = 58 Ω^-1 cm^-1) is much higher than that of (Net₄)-[Pd(dmit)₂]₂ (σ = 2.2 Ω^-1.cm^-1) has been rationally explained by the results of energy band calculations. (MeNEt₃)[Pd(dmit)₂]₂ belongs to monoclinic system, P2₁/m space group and (Net₄)[Pd (dmit)₂]₂ belongs to triclinic system, space group. The structural conducting component of the crystals is the planar coordinative anion [Pd(dmit)₂]^0.5- which forms the face-to-face dimmer. [Pd(dmit)₂]^- ₂These dimers have been further constructed to be a kind of two-dimensional (2-D) conductive molecular sheet by means of S_S intermolecular interactions. The tiny difference of the above 2-D molecular sheets of the two title crystals has resulted in one order of magnitude difference of conductivities.     

Selective formation of trans and cis(CH3CN) isomers of [Ru(bpy)(CO)2(CH3CN)2] (bpy=2,2-bipyridine) from [Ru(CO)2(CH3CN)3]2(PF6)2 using an electrochemical oxidation step

The selective in situ synthesis of trans and cis(CH₃CN)-[Ru(bpy)(CO)₂ (CH₃CN)₂]²⁺ isomers from the same [Ru(CO)₂ (CH₃CN)₃]₂²⁺ dimer precursor but using either an electrochemical-chemical or chemical-electrochemical process is described.     

混合价三核锰配合物Mn3O(O2CCCl3)6(py)2(H2O)的合成、晶体结构及磁性

A new mixed-valence trinuclear oxo-centered manganese complex Mn₃O(O₂CCCl₃)₆(py)₂(H₂O) was prepared by the reaction of NⁿBu₄MnO₄ with Mn(OAc)₂·4H₂O, trichloroacetic acid and pyridine in absolute EtOH. The crystal structure was determined. The complex crystallizes in monoclinic, space group P2₁/c, unit cell parame-ters, a=14.951(1), b=20.791(2), c=17.882(1)?,α=γ=90°, β=102.67(1)°. Variable temperature solid state magnetic susceptibility study shows that the complex has an antiferromagnetic exchange interaction. CCDC: 183369.     

配合物[La(pic)3(phen)2]·CH3CN的合成及晶体结构

The Lanthanum picrate complex with 1,10-phenanthroline was synthesized, whose chemical formula can be written in [La(pic)₃(phen)₂]·CH₃CN. The crystal Xray diffraction analysis shows that crystal belongs to monoclinic with space group P2₁/a and unit cell parameters:a=17.072(4),b=16.083(4),c=17.789(4),β=106.34(2)°,V=4687(4)³, Z=4,Dc=1.735g·cm³, μ=10.106cm¹,F(000)=2448,R=0.0589,Rw=0.0589. The coordination number of La³⁺ is nine. Acetonitrile, a solvent molecule is not coordinated. Between three Pic ligands, that possesses 2 bidentate forms six member ring with La. The other is unidentate ligand. As usually, phen is bidentate ligand.     

Crystal structure of a novel Hg(II) complex, [Hg(tri-2-furylphosphine)2(tri-2-furylphosphinoxide)3] [ClO4]2

The Hg(II) complex [Hg(TFP)₂(OTFP)₃][ClO₄]₂ with TFP=tri-2-furyl-phosphine and OTFP=tri-2-furylphosphinoxide has been prepared and characterised. It crystallises in the hexagonal P6₃/m space group with Z=2, a=13.308(3), c=21.092 (4) Å, V=3235(1) Å³. The structure of the complex cation consists of independent molecules with Hg pentacoordinated in exact trigonal bipyramidal geometry.     

C-H Activation of 3,3-diphenylcyclopropene in the reaction with Os(CO)2(PPh3)3: 3,3-diphenylcyclopropenyl, 2,2-diphenylcyclopropyl, and 3-phenylindenyl complexes of osmium(II)

Reaction between Os(CO)₂(PPh₃)₃ and 3,3-diphenylcyclopropene under quartz-halogen irradiation leads to C(sp²)-H bond activation and the formation of the 3,3-diphenylcyclopropenyl complex, OsH[C₃H(Ph-2)₂](CO)₂(PPh₃)₂ (1). When complex 1 is heated there is ring-opening of the cyclopropene ring and rearrangement to the 3-phenylindenyl complex, OsH[C₉H₆(Ph-3)](CO)₂(PPh₃)₂ (2). Compound 1 reacts with HCl forming the 2,2-diphenylcyclopropyl complex, OsCl[C₃H₃(Ph-2)₂](CO)₂(PPh₃)₂ (3). Reaction of either 1 or 3 with excess HCl leads to reversible formation of the hydroxycarbene complex, OsCl₂[C(OH)C₃H₃(Ph-2)₂](CO)(PPh₃)₂ (4), through protonation of the acyl group formed by a migratory insertion reaction involving a carbonyl ligand and the σ-bound 2,2-diphenylcyclopropanyl ligand. An X-ray crystal structure determination of 2 is reported.     

Synthesis and Structural Characterization of Manganese Carbonyl Incorporated Polyoxomolybdate （n-Bu4N）2 [Mo6O16（OCH3）2 {HOCH2C（CH2O）3}2 {Mn（CO）3}2]

The polyoxoanion incorporated {Mn（CO）3^＋} complex, （n-Bu4N）2[Mo6O16（OCH3）2{HOCH2C（CH2O）3}2·{Mn（CO）3}2]（1）, has been synthesized by the reaction of （n-Bu4N）4[Mo8O26] with Mn（CO）5Br in methanol, in the presence of C（CH2OH）4. The complex 1 has been characterized by IR, UV-Vis, X-ray single crystal diffraction, and TG. Crystal data for the complex 1：C25H48MnMo3NO16 （1）, Triclinic Pi, a=0.9405（3） nm, b=1.3351（4） nm, c=1.5455（4） nm, α=103.206（5）°, β=102.165（5）°, γ=100.784（5）°, V=1.7896（9） nm^3, Z=2, R1=0.0703, wR2= 0.1495. The structure analysis of complex 1 shows that the complex consists of two tetrabutylammonium cations and a polyoxomolybdate anion that incorporates two fac-Mn（CO）3^＋ units. The anion of complex 1 can be considered as the dimer of two rhomb-like anions by sharing of two comers.     

A 2-iridathiophene from reaction between IrCl(CS)(PPh3)2 and Hg(CHCHPh)2

The thiocarbonyl analogue of Vaska’s compound is produced in high yield by first treating IrCl(CO)(PPh₃)₂ with CS₂ and methyl triflate to give [Ir(κ²-C[S]SMe)Cl(CO)(PPh₃)₂]CF₃SO₃ (1), secondly, reacting 1 with NaBH₄ to give IrHCl(C[S]SMe)(CO)(PPh₃)₂ (2), and finally heating 2 to induce elimination of both MeSH and CO to produce IrCl(CS)(PPh₃)₂ (3). When IrCl(CS)(PPh₃)₂ is treated with Hg(CHCHPh)₂ the novel 2-iridathiophene, Ir[SC₃H(Ph-3)(CHCHPh-5)]HCl(PPh₃)₂ (4) is produced. The X-ray crystal structure of the iodo-derivative of 4, Ir[SC₃H(Ph-3)(CHCHPh-5)]HI(PPh₃)₂ (5) confirms the unusual 2-metallathiophene structure. Treatment of IrCl(CS)(PPh₃)₂ with Hg(CHCPh₂)₂ produces both a coordinatively unsaturated 1-iridaindene, Ir[C₈H₅(Ph-3)]Cl(PPh₃)₂ (6) and a chelated dithiocarboxylate complex, Ir(κ²-S₂CCHCPh₂)Cl(CHCPh₂)(PPh₃)₂ (7). X-ray crystal structure determinations for 6 and 7 are reported.     

[Pb2(TNR)(NO3)2(H2O)]的制备和晶体结构研究

[Pb₂(TNR)(NO₃)₂(H₂O)] was prepared by reaction of the aqueous solution of lead nitrate and magnesium styphnate. The crystal structure of Pb₂(TNR)(NO₃)₂(H₂O)was determined by single crystal diffraction analysis. The crystal is triclinic, space group P1 with crystal parameters a=0.7279(2)nm,b=1.0698(2)nm,c=1.0738(2)nm;α=86.82(1)°,β=89.52(2)°,γ=83.50(2)°;V=0.8295(3)nm³,Z=2,D_c=3.201g·cm^-3, F(000)=716. The final R value is 0.0358.In the crystal structure, one lead ion was represented by nine coor-dination geometry; the other was showed as ten coordination geometry.     

茂金属配合物[Mo(eta5-C5H4Si2Me5)(CO)3Cl]的晶体结构和量子化学研究

The crystal structure of tricarbonylpentamethyldisilanylcyclopentadienyl chloro-molybdenum complex [Mo(eta⁵-C₅H₄Si₂Me₅)(CO)₃Cl] has been determined by X-ray diffraction method.A quantum chemistry calculation by means of G98W package and taking LanL2DZ basis set.The crystal belongs to orthorhombic space group Pbca with a=1.5812(5), b=1.7307(3), c=1.3339(2)nm,V=3.650(1)nm³, Z=8, D_c=1.495 g·cm^-3, μ(MoKα)= 9.97cm^-1,F(000)=1664,final R=0.027 for 2590 unique reflection [I >3σ(I)]. The bond lengths of Mo-Cl and is 0.250nm,and Mo-CO is 0.198～0.202nm. The Mo atom has a distorted tetrahedral cone geometry.