THE CRYSTAL STRUCTURE OF [Co(TPPO)_4][Co (NCS)_3TPPO]_2

The title complex [Co(TPPO)_4] [Co(NCS)_2TPPO]_2 (TPPO=triphenylphosphine oside) was prepared by solvent evaporation method. Its crystal structure was determined by x-ray diffraction method. The crystal is rhombohedral with space group R3. The unit cell parameters are presented and the structure has been refined to a final R of 0.064.     

THE CLEAVAGE REACTION OF Mo≡Mo TRIPLE BOND.SYNTHESIS AND X-RAY CRYSTAL STRUCTURE OF[CpMo(CO)_2(N,S-C9H6NS)]·O=PPh3

The reaction of[CpMo(CO)_2]_2 with 8,8'-diquinolyl disulphideC_9H_6NSSNC_9H_6 resulted in the cleavage of Mo≡Mo triple bond to give a newnononuclear complex CpMo(CO)_2(N,S-C_9H_6NS)which was refluxed with PPh_3 inTHF to form the title complex.The crystal structure of the title complexwas determined by X-ray diffraction.     

HYDROFORMYLATION OF 1-HEXENE WITH Rh_4(CO)_(12) AND [Rh(CO)_2Cl]_2

The hydroformylation of hexene-1 catalyzed by Rh_4 (CO)_12 and 〔Rh(CO)_2Cl〕_2 andthe effects of solvents (benzene, n-heptane and THF) and PPh_3 on the activity andselectivity of the catalysts were studied.The results indicated that the activity of Rh_4(CO)_(12) decreased with increasing solventpolarity and it did not change appreciably with addition of PPh_3 when the molar ratioPPh_3/Rh_4(CO)_(12)≤4. Thc activity of Rh_4(CO)_(12) was over twice as large as that of〔Rh(CO)_2Cl〕_2 when calculated according to the number of moles of rhodium clusters inbenzene without PPh_3, but the activities of both Rh_4(CO)_(12) and 〔Rh(CO)_2Cl〕_2 wereabout the same when calculated according to the number of rhodium atoms. It is suggestedthat the clusters probably dissociated into the similar active rhodium mononuclear speciesunder the reaction conditions and the species formed a cluster similar to Rh_4(CO)_(12) againwhen the conditions were reduced to the ambient temperature and pressure.     

SYTHESE AND REACTIONS OF HETEROBINUCLEAR COMPLEXES [PhCl_2SnM(Cl)(CO)_3(CH_3CN)_2] (M = Mo, W)

Abstract The complexes [M(CO)_3(CH_3CN)_3](M=Mo, W)react with an equimolar quantity ofPhSnCl_3 in dichloromethane at room tempreture to afford new heterobinuclearcomplexes [PhCl_2SnM(Cl)(CO)_3(CH_3CN)_2] [M=Mo(1); W(2)]. The complexes reactwith two equivalents of PR_2R'(R=Ph, R'=Ph, Me; R=Cy, R'=H) to yield stablecomplexes [PhCl_2SnM(Cl)(CO)_3(PR_2R')_2]. Reaction of[PhCl_2SnM(Cl)(CO)_3(CH_3CN)_2]with one equivalent of PPh_2(CH_2)nPPh_2(n=I,2) or bulky phosphine ligands PBu_2~tClin dichloromethane at room tempreture to give [PhCl_2SnMo(Cl)(CO)_3{PPh_2(CH_2)n-PPh_2}] .CH_2Cl_2, [PhCl_2SnMo(Cl)(CO)_3PBu_2~tCl]. CH_2Cl_2, respectively. The complexes1 and 2 react with phosphite donor ligands P(OMe)_3 to give [PhCl_2SnM(Cl)(CO)_2-{P(OMe)_3}_3]. All complexes have been characterized by elemental analysis, IRand ~1HNMR spectroscopies. Here we report the preliminary results of this work.     

STUDY OF THE REACTION MECHANISM OF CYCLOHEXENE HYDROGENATION CATALYZED BY RhCl(PPh_3)_3

The hydrogenation rate of styrene in benzene using RhCI(PPh_3)_3 as catalyst increases with the concentration of styrene. But the hydrogenation rate of cyclohexene is rather different, It shows a maximum. So we inquire into the reaction mechanism of cyclohexene hydrogenation catalyzed by RhCI(PPh_3)_3. The rate of hydrogenation was measured at 25±0.15℃, as a function. of catalyst concentration, olefin concentration, triphenylphosphine concentration and hydrogen pressure. The maximum of the reaction rate is interpreted by the formation of RhClL_2S_2. The rate determining step is considered to be the reaction of olefin insertion into one of the Rh-H bonds formed by hydrogenation of RhClL3 to H_2RhClL_3. The hydrogenation rate of the substrate can be described by a third order equation in terms of concentration of H_2RhClL_3. Average error between the results evaluated by this equation and experimental results is about 4.9％. The quantum chemistry calculation gives support to the present mechanism.     

Enantioselective hydrogenation of acetophenone by(1S,2S)-DPEN-Ru(Ⅱ)Cl_2(PPh_3)_2 encapsulated in Al-MCM-41

<正>A chiral ruthenium complex[(1S,2S)-DPEN]-RuCl_2(PPh_3)_2(DPEN = 1,2-diphenylethylenediamine,PPh_3 = triphenylphosphine) was encapsulated in the channel of Al-MCM-41 by electrostatic adsorption and 1,1-dichlorosilacyclobutane modification.The prepared heterogeneous catalyst showed the same catalytic activity and enantioselectivity as the corresponding homogeneous catalyst in the asymmetric hydrogenation of acetophenone,and could be reused at least seven times without significant loss of catalytic activity and enantioselectivity.     

Nitrosyl Complexes 6.Reactions of Na[Fe(CO)_3NO]with Cp~*M(CO)_3Cl(Cp~*=η~5-CH_3C_5H_4,M=Mo or W):Crystal structures of Cp~*M(CO)_2NO and Cp~*M(μ_3-NH)(μ_2-NO)(μ_2-CO)Fe_2(CO)_6

Sodium nitrosylcarbonyliron reacts with methylcyclopentadienylcarbonylmetal(Mo orW)chloride in CH_3OH/THF at room temperature to give CpMo(CO)_2NO(1a)(Cp=η~5-CH_3C_5H_4)or CpW(CO)_2NO(1b),[CpMo(CO)_3]_2(2a)or[CpW(CO)_3]_2(2b),and CpMo(μ3-NH)(μ2-NO)-(μ2-CO)Fe_2(CO)_6(3a)or CpW(μ3-NH)(μ2-NO)(μ2-CO)Fe_2(CO)_6(3b),respectively.Complexes1a,1b,3a and 3b were analyzed by IR,NMR,MS and elemental analyses,and the crystalstructures of 1b,3a and 3b were determined by X-ray diffraction method.The new clusters 3aand 3b have μ3-NH ligands which were formed by redaction of NO in the synthetic reactions.     

THE CATALYSIS OF IRON-COBALT BIMETALLIC CLUSTERS——1.THERMAL STABILITY AND DECOMPOSITION REACTION OF[R_4N][FeCo_3(CO)_(12)]IN SOLUTION

Thermal decomposition of[R_4N][FeCo_3(CO)_(12)][I](R=ethyl,butyl,hexadecyl,benzyltrimethyl,benzyltriethyl)in n-heptane,toluene and methanol was investigated bythe in situ high pressure IR spectroscopic method.The results show that underhydroformylation conditions all clusters decompose to Co_2(CO)_8,Fe(CO)_5 and the salt ofCo(CO)_4~-,and Co_2(CO)_8 reacts with H_2 to form HCo(CO)_4.Thermal stability of theclusters decrease with the increase of polarity of solvents.Under the hydroformylation con-ditions,IR spectra of the clusters are compatible with those of Fe(CO)_5+Co_2(CO)_8+[R_4N]Cl system.Because of the stabilizing effect or tetra-alkylammonium cation,when the tem-perature drops below 50℃ after decomposition of the clusters,the characteristic absorptionbands of the clusters appear again,so the decomposition process is reversible.     

SYNTHESIS AND CRYSTAL STRUCTURE OF MgCl_2(CH_3COOC_2H_5)_2

The crystal of the title compound was prepared and its structure determined by X-ray diffraction method.1672 independent reflections were collected. The crystal is orthogonal with space group P2_12_12, and a=7.353(3),b=25.111(10), c=8.631(2), Z=8. The structure was solved by using Patterson method and modified with LSM program.The final R= 0.0795. The structural features of the title compound are:Mg(Ⅱ) is octahedral and ethyl acetate is located on trans-position.Mg atoms are connected by double chloro-bridge and form polychains.     

Reactivity of Fe_3(CO)_(12) with Alkynes R-C≡C-R': Syntheses and Crystal Structures of Substituted Cyclic Ketones and Carbonyl Iron Complexes

The reactivity of carbonyl iron cluster with alkynes has been studied by the thermal reaction of Fe_3(CO)_(12) with R-C≡C-R'(R = Fc(Ferrocenyl); R′ = Ph(Phenyl), Fc, H). The hexacarbonyldiiron cluster with ferracyclopentadiene ring(μ_2, η~4-C_4Ph_4)Fe_2(CO)_6(1) and one tetraphenyl substituted cyclopentadienone(Ph_4C_4CO)(2) were simultaneously obtained by the reaction of Fe_3(CO)_(12) with alkyne(Ph-C≡C-Ph). Only one ferrole cluster(μ_2, η~4-C_4Fc_2H_2)Fe_2(CO)_6(3) was separated by using Fc-C≡C-H as alkyne. One tri-carbonyl iron complex(η~4-C_4Fc_4CO)Fe(CO)_3(4) and an unexpected new cyclic ketone compound 2,2,4,5-tetraferrocenylcyclopenta-4-en-1,3-di-one [Fc_4C_3(CO)_2](5) were obtained by using Fc-C≡C-Fc as alkyne. A new complex(η4-2,4-diphenyl-3,5-diferrocenylcyclopenta-2,4-dien-1-one)-tricarbonyl iron(η~4-C_4Ph_2Fc_2CO)Fe(CO)_3(6) was synthesized by the reaction of Fe_3(CO)_(12) with Fc-C≡C-Ph. The structures of compounds 1~6 were determined by X-ray single-crystal diffraction and spectroscopic characterization. The crystal structures of two new compounds 5 and 6 were analyzed. Our experimental results reveal the structural models of the reaction products are affected by the kinds of substituents from alkynes R-C≡C-R′.     

Syntheses and Structures of Two Ruthenium(III)Complexes [Ru(PPh_3)_2(S_2CNR_2)Cl_2]·CH_2Cl_2(R=Et and ~iPr)

Oxidation reaction of [Ru(PPh_3)_3Cl_2] with tetraethylthiuram disulfide[Et_2NCS_2]_2 or tetra-iso-pmpylthiumm disulfide[~iPr_2NCS_2]_2 afforded mthenium(Ⅲ)complexes[Ru(PPh_3)_2(S_2CNR_2)cl_2]·CH2Cl2(R=Et 1,~iPr 2)which were characterized by single-crystal X-ray diffraction.Complex 1 crystallizes in triclinic,space group Pīwith a=11.5065(6),b=12.1458(7),C=18.0034(9)(A),α=109.380(4),β=95.279(4),γ=97.969(4)°,ν=2324.8(2)(A)~3 and Z=2.Complex 2 belongs to the monoclinic system,space group P21/n with a=12.5752(3),b=20.7562(5),e=17.6821(3)(A),β=105.934(1)°,ν=4437.94(17)(A)~3 and Z=4.Both mononuclear complexes 1 and 2 have an octahedral configuration around the central ruthenium atom which is bonded to one chelated dithiocarbamate ligand,two PPh_3 ligands in mutually tram and two chlorides in mutually cis positions.The average Ru-S,Ru-P and Ru-Cl bond lengths are 2.377(2),2.412(2)and 2.369(2)(A) for 1,and 2.376(2),2.414(1)and 2.383(2)(A) for 2,respectively.The electrochemical properties of these two complexes were studied in CH_2Cl_2 solution by cyclic voltammetry.     

RESEARCH ON TRINUCLEAR MOLYBDENUM CLUSTER COMPOUNDS——CRYSTAL AND MOLECULAR STRUCTURE OF (C_5H_7S_2)_3[Mo_3(μ_3-S)(μ_2-S_2)_3Cl_7]

The space group of the title crystal is Pnam. The unit cell parameters are: a=17.226(4), b=14.306(7), c=15.074(4); z=4, Dobs=2.03g·cm~(-3), D_(calc)=2.063g·cm~(-3). The crystal structure was solved by the heavy atom method and refined by the full-matrix least-squares until the final conventional discrepancy factor was reduced to 0.068. The results of the investigation show that the crystal consists of trinuclear Mo cluster anions [Mo_3(μ_3-S)(μ_2-S_2)_3Cl_7]~(3-) together with planar (C_5H_7S_2)~ monocations, surrounding the cluster anions. In the cluster anion three Mo atoms, forming a nearly equilateral triangle (2.755(1), 2.755(1), 2.743(1)), are bound by a μ_3-S bridging atom, while each pair of Mo atoms is bridged further by a μ_2-S_2 ligand. Besides, each Mo atom is coordinated to two terminal Cl atoms, so that the coordination sphere of each Mo atom approaches closely a pentagonal bipyramid. In addition, a single Gl atom, not at all involved in the coordination spheres of the three Mo atom     

Synthesis, Reaction and Structures of Functionally Substituted η~5-Cyclopentadienyl Compounds With Cr≡S Triple Bond [η~5-RC_5H_4Cr(CO)_2]_2S (R=CH_3C(O),CH_3O_2C,C-2H_5O_2C,CH_3CH(OH),CO_2H)

[η_5-OH_3C(O)C_5H_4Cr(CO)_2]_2S 1, [η~5-CH_3O_2CC_5H_4Cr(CO)_2]_2S 2 and [η~5-C_2H_5O_2CC_5H_4Cr(CO)_2]_2S 3 were prepared by the reactions of corresponding sodium salts of functional η~5-cyclopentadienyl-tricarbonylchromium anions with SOCl_2. Reduction of 1 with NaBH_4 prdouced [η~5-CH_3CH(OH)C_5H_4Cr(CO)_2]_2S 4, while saponification of 2 followed by acidification and recrystallization from acetone afforded [η~5-HO_2CC_5H_4Cr(CO)_2]_2S·nCH_3C·(O)CH_3 5. 1—5 are a new class of Cr≡S triple bond compounds containing functional organic group on the cyclopentadienyl ring. A single-crystal X-ray diffraction analysis of 1 revealed that it consists of two identical organometallic fragments η~5-CH_3C(O)C_5H_4Cr(CO)_2 joined together by a sulfur atom via triple bonds. The geometry of structural unit Cr≡S≡Cr belongs to linearity and the average triple bond length of Cr≡S is 2.072(?).     

THE STATE OF CHROMIUM (Ⅲ) ION IN AQUEOUS SOLUTION

So far few systematic studies on the hydrolytic polymerization of Cr(Ⅲ) were reported because of inertness of the ion and complication of the process. We studied it in equilibrium by pH method systematically in a wide concentration range (0.0002—0.32 M). The results show that, in the low concentration range, the composition of the polynuclear hydrolysis products may be represented as [Cr_3(OH)_4] (OH)_n (n=1,2,3); in the medium range, the composition of products as Cr[Cr(OH)_2]_n~((3+n))~+ (n=1,2,3); in the high range, the composition of products as Cr[Gr(OH)]_n~((3+2n))~+ (n=1, 2), and in the intermediate range between medium and high range where the hydrolysis system is in a transition state, the composition of products as [Cr_3(OH)_3]~(6+) and [Cr_3(OH)_4]~(5+). The values of hydrolysis constants of the identical species measured in different Cr concentration ranges and calculated by different methods were found in good agreement with each other. A predominance-arca diagram was made by using the hy     

A CLUSTER COMPOUND WITH DI-ENDOXYGEN LIGANDS——THE CRYSTAL AND MOLECULAR STRUCTURE OF [Fe(MOS_4O)_2][N(C_2H_5)_4]3

[Fe(MoS_4O)_2] [N(C_2H_3)_4]_3 cluster compound with di-end-oxygen ligands has been prepared and characterized by the X-ray diffraction method. The compound crystallizes in a monoclinic space group P2_1/n with lattice parameters a=13.019(4), b=16.959(5), c=18.234(5), β=97.34(2)(°), Z=4. The final agreement factors are R=0.0740, Rw=0.0598. The terminal bond length, Mo-S_t and bridged one, MO-S_b for the compound are much longer than the counterpart without end-oxygen ligand. It possibly suggests that low valence of molybdenum and smaller electronegativity of sulphur than oxygen lead to the charge transfer as S→Mo→O.     

STUDY ON TRINUCLEAR MOLYBDENUM CLUSTER COMPOUNDS——THE CRYSTAL AND MOLECULAR STRUCTURE OF THE TWO TRINUCLEAR MOLYBDENUM CLUSTERS(C_5H_7S_2)[Mo_3(μ_3-O )(μ-X)_3(μ-OAc)_3Cl_3](X=Cl,Br)

The crystal structure of two isomorphic cluster compounds with formula (C_5H_7S_2)-[Mo_3(μ_3-O)(μ-X)_3(μ-OAc)_3Cl_3] (X=Cl for compound (Ⅰ) and compound (Ⅱ)) has been investigated by X-ray diffraction method. The parameters of two crystals are: a=10.423(1),b=17.095(4), c=14.062(7), β=97.54(4)(°); Dc=2.20gcm~(-3), D_o=2.17g cm~(-3) for compound (Ⅰ). and a=10.511(3), b=11.213(2), c=14.053(3), β=96.12(2)(°); D_c=2.52g cm~(-3), D_o=2.53gcm~(-3) for compound (Ⅱ). The space groups are P2_1/C. Z=4. The 2621 and 2548 independent reflections with I>3σ(I) were collected on a CAD-4 four-circle diffractometer by means of MoKα radiation. The crystal structures were solved by heavy atom method and refined by full-matrix least-squares technique to a final discrepancy factors of R=0.061 and 0.051 respectively. The results of investigation show that the molecule consists of the cation (C_5H_7S_2)+ and the trinuclear Mo cluster anion, the configuration of which is similar to that of (Et_4N)_2[Mo_3(μ_3-O)(μ     

THE SYNTHESIS AND CRYSTAL STRUCTURE OF A NOVEL MOLYBDENUM-COPPER-SULFUR CLUSTER COMPOUND [(CH_3CH_2 )_4N]_2 [(μs-S)CusS_6(S_2)_6Mo_6O_6].DMF

The synthesis and crystal structure of a novel molybdenum-copper cluster compound with [(μs-S)Cus] core is reported. It was prepared from Cu2Br2 upon reaction with molybdenum sulfur compound [CH3CH2)4N]2[Mo2O2S2-(S2)(S4)]. The title compound crystallizes in the monoclinic system space group Cc with cell dimensions: a=21.320(5), b=21.869(3), c=13.029(5)A,β=118.28(1)°,Z=4, V=5349A3 and Dc=2.48 g.m-3. The structure has been determined by Patterson and Fourier methods and then refined by the least squares method to a final R of 0.053. There are some distortions from octahedron in configuration of the [(μs-S)Cu6]6 core with three weak Cu-Cu bonds.     

HETERONUCLEAR COMPLEX CONTAINING COPPER-LANTHANIDE ARRAYS: THE SYNTHESIS AND CRYSTAL STRUCTURE OF Ln_2Cu_4L_8 (HL)_4(OH)_2(CIO_4)_4(H_2O)_(10)·2CH_3COCH_3 (Ln = Tb (1), Y (2); HL = 2-Pyridone C_5H_5NO)

Reaction of 2-pyridone, copper acetate and terbium(or yttrium) perchlorate in acetone with the moleratio 6: 2: 1 results in the formation of heteronuclear complex Ln_2Cu_4L_8 (HL)_4 (OH)_2 (ClO_4)_4 (H_20)_(10)2CH_3COCH_3(Ln = Tb (1), Y (2)). By recrystallizing (1) in CHCl_3 single crystals were obtained and thestructure was determined by four-circle diffractometer. Data showed that the crystal is in space groupC2/m with a=27. 454(9)A, b=13, 608A, c=30. 556(11)A, β=99. 89(3)°, v=11245. 7(7. 5)A~3. Thestructure was solved by a combination of Patterson method and Fourier technique. The final R value is0. 103. In the structure, four copper and two terbium ions are bridged by 2-pyridone anions to form anessentially octahedral Cu_4Tb_2 core. The terbium atoms are each eight-coordinate and the copper atomsare five-coordinate.     

STUDY ON STRUCTURE OF SULFUR-BRIDGED TRANSITION METAL CLUSTERS——CRYSTAL AND MOLECULAR STRUCTURE OF (C_5H_7S_2)_3 [Mo_3(μ_3-S)_2 (μ_2-Cl)_3Cl_6]

The compound (C_5H_7S_2)_3[Mo_3 (μ_3--S)_2 (μ_2--Cl)_3 Cl_6] forms dark black octahedralcrystals with the following crystallographic parameters: a=22.885(10)A, c=25.407(7)A. Thespace group is I4_1/α, Z=16, ρ_(obs.)=2.073g/cm~3, ρ_(calc.)=2.126g/cm~3. The 1621 independentreflections with I≥3σ were collected on a CAD-4 four-circle diffractometer by means of MoK_αradiation. The structure was solved by three-dimensional Patterson synthesis and refined byleast squares technique to a final discrepancy factor of R=0.056. The results of our investiga-tion reveal that the molecule consists of a trinuclear Mo cluster anion and three planar mono-cations.surrounding the cluster anion. As the core of the anion the triad of Mo atoms, possessing anequilateral triangular configuration, is linked by two μ3--S bridging atoms and three μ2--Clatoms. Besides, two terminal Cl atoms are attached to each Mo atom to form an octahedralconfiguration. The diamagnetism and the short Mo-Mo distances (2.556 A, 2.641 A, 2.653 A)clearly indicate the existence of Mo-Mo bonds. The anion as a whole has an idealized D_(3h) localsymmetry.     

RESEARCH ON TRINUCLEAR MOLYBDENUM CLUSTER COMPOUNDS——CRYSTAL AND MOLECULAR STRUCTURE OF Mo_3(μ_3—O)(μ_2—S_2)_3[S_2P(OEt)_2]_3I

The title crystals are golden yellow rhomboic plates, belonging to the monoelinic system. The space group is P_(B_1)/n with unit cell parameters a=16.570(2), b=12.370(1), c=20.007(2), β=99.97(1)°, Z=4, D_c=1.938 g.cm~(-3). The crystal structure was solved mainly by the heavy atom method and refined by the full-matrix least-squares to a final R factor of 0.047 based on 4387 unique reflections with intensities I≥2σ(I). The results show that the crystal structure consists of neutral mono-oxo-capped trinuclear molybdenum cluster molecules with an average Mo-Mo bond length of 2.626(4) and an average Mo-O bond length of 2.036(2) respectively. Each pair of Mo atoms is further bridged by an S_2~(2-) radical, in which one S atom is essentially situated on the triangular plane formed by these three Mo atoms and the other one is situated on the side of the plane opposite to the μ_3-O atom. Besides, each Mo atom is coordinated to two S atoms belonging to an [S_2P(OEt)_2]~-radical so as to complete a nearly pen