Synthesis and Crystal Structure of Cubane-type Molybdenum Cluster Complex Mo_4S_4(DTP)_4[μ-SOP(OEt)_2]_2

A cubane-type molybdenum cluster compound Mo4S4(DTP)4[-SOP(OEt)2]2 A (DTP = diethyl dithiophosphate) was obtained from the reaction of cation [Mo3O2S2(H2O)9]4+ B with metal tin as well as HDTP. The crystal structure has been determined by X-ray crystallography and the data for the title compound: Mo4S14P6O14C24H60, triclinic P , Mr = 1591.14, a = 12.5596(5), b = 14.3441(5), c = 18.0005(6) ? = 85.318(1), = 70.495(1), = 78.415(2)? V = 2994.2(2) ?, Z = 2, Dc = 1.765 g/cm3, (MoK? = 1.515 mm-1, F(000) = 1596, R = 0.0918 and wR = 0.1908 for 3546 reflections (I > 2(I)). X-ray analysis reveals that two weak CH贩稯 hydrogen bonds exist in the packing diagram with C贩稯 distance 3.22(5) ? The structure of A is similar to that of -Mo4S4(DTP)6 except that one sulfur of each bridging DTPs has been replaced by oxygen during the reaction, resulting in two bridging [SOP(OEt2)2] - ligands.

SYNTHESIS AND STRUCTURE OF TETRANUCLEAR MOLYBDENUM CLUSTER COMPOUND[Mo_4S_4(μ-O_2CC_6H_5)_2(dtp)_4]

The cluster compound[Mo_4S_4(μ-O_2CC_5H_5)_2(dtp)_4](dtp=S_2P(OEt)_2)was obtained by the ligand substitution reaction of tetranuclear molybdenum cluster [Mo_4S_4(μ-dtp)_2(dtp)_4]in the mixed solvent of acetone,ethanol and water in the presence of C_6H_5CO_2Na.It is monoclinic and crystallizes in space group C2/c, Mr=1495.09,a=12.175(5),b=22.01(1),c=20.875(9),β=99.04(4)°;V=5575(5);Z=4; Dc=1.78g/cm^3.Final R factor is 0.066.The result reveals that the[Mo_4S_4]cluster core and t-(dtp)^(-1)ligands are retained and only μ-bridged(dtp)^(-1)ligands are substituted by(C_6H_5CO_2)^(-1)in the substitution reaction,thus producing the new title cluster compound,the structure of which contains two species of bidentate ligand.

MOLECULAR AND CRYSTAL STRUCTURES OF TETRANUCLEAR MOLYBDENUM CLUSTER[Mo_4(μ_3-O)_2O_4Cl_2(o-CH_3C_6H_4COO)~6]■

The new cluster[Mo_4(μ_3-O)_2O_4Cl_2(o-CH_3C_6H_4COO)_6]has been prepared by the reaction of molybdenum pentachloride and o-methylbenzoic acid.The crystal and molecular structures were determined by the X-ray diffraction method.It crystallizes in the orthorhombic space group Pnna with cell parameters:Mr=1361.6,a=13.792(4), b=17.957(3),c=20.974(9) ,V=5194(2) ~3,Z=4,Dc=1.74/cm^3,F(OOO)=2704,μ(MoK ) =11.0/cm,R=0.074.

Catalytic epoxidation of olefin over supramolecular compounds of molybdenum oxide clusters and a copper complex

The catalytic epoxidation of olefin was investigated on two copper complex-modified molybdenum oxides with a 3D supramolecular structure, [Cu（bipy）]4[Mo15O47].2H2O （1） and [Cu1（bix）][（Cu1bix） （δ-MoVl8O26）0.5] （2） （bipy = 4,4＇-bipyridine, bix = 1,4-bis（imidazole-1-ylmethyl）benzene）. Both compounds were catalytically active and stable for the epoxidation of cyclooctene, 1-octene, and styrene with tert-butyl hydroperoxide （t-BuOOH） as oxidant. The excellent catalytic performance was attributed to the presence of stable coordination bonds between the molybdenum oxide and copper complex, which resulted in the formation of easily accessible Mo species with high electropositivity. In addition, the copper complex also acted as an active site for the activation of t-BuOOH, thus im- proving these copper complex-modified polyoxometalates.

A dinuclear molybdenum cluster containing i-mnt ligand: synthesis and crystal structure of [Mo_2S_4(i-mnt)_2] (Et_4N)_2

A dinuclear molybdenum(V) cluster compound (Et4N)2[Mo2S4(i-mnt)2] (i-mnt=l,l-dicyanoethylene-2,2-dithiol, (S2C=C(CN)2]2-) has been prepared by the ligand substitution reaction of Mo2S4(iso-pr2dtp)2 (iso-pr2dtp=S2P(OC3H7)2-) with K2(i-mnt) in the presence of Bt4NI. This cluster was characterized by inrrared spectrum, UV-Vis spectrum and single crystal structure analy-sis. The cluster anion [Mo2S4(i-mnt)2]2- possesses C, symmetry with a crystallographic mirror plane through two bridging S atoms. By the S....S supramolecular interactions between two adjacent cluster anions the [Mo2S4(i-mnt)2]2- anions are linked to form infinite chains along the b axis. Crystal data: monoclinic, space group C2/m, a=1.8748(6), b=1.5360(4), c=1.4322(5) nm, ,β=112.02(2)°, V=3.823(4) nm3, Z=4, Dc=1.50 g/cm3. The final R=0.038 and .RW=0.053 for 3015 observed unique reflections.

^(31)P NMR Studies on the Ligand Dissociation of Trinuclear Molybdenum Cluster Compounds

A series of carboxylate-substituted trinuclear molybdenum cluster compounds formulated as Mo 3S 4(DTP) 3(RCO 2)(L), where R=H, CH 3, C 2H 5, CH 2Cl, CCl 3, R 1C 6H 4 (R 1 is the group on the benzene ring of aromatic carboxylate), L=pyridine, CH 3CN, DMF, have been synthesized by the ligand substitution reaction. The dissociation of the loosely-coordinated ligand L from the cluster core was studied by 31P NMR. The dissociation process of L is related to the solvent, temperature, and acidity of carboxylate groups, so as to affect the solution structure and reactive properties of the cluster. The long-distance interaction between ligands RCO 2 and L is transported by Mo 3S 4 core.

Synthesis and structure of an open-type trinuclear molybdenum cluster compound[Mo_3(μ_3-S)(μ-S)_2-(μ-OAc)(S_2CNC_4H_8)_3(O)_2]·0.5CH_2Cl_2·2H_2O

The title compound was prepared by the reaction of Mo_3S_4(dtp)_4(H_2O)[ctp=S_2P(OEt)_2] with NaOAc·3H_2O and C_4H_8NCS_2NH_4.Crystallographic data:[Mo_3(μ_3-S)(μ-S)_2(μ-OAc)- (S_2CNC_4H_8)_3(O)_2]·0.5CH_2CI_2·2H_2O,Mr=980.18,triclinic,space group P(?),α=12.360(3),b=16.653(6), c=9.206(2)A,α=101.97(2),β=108.32(2),γ=86.14(3)°.V=1759.6(9)A^3,Z=2,Dc=1.85 g/cm^3, F(000)=962,μ(Mo K_α)=16.53 cm^(-1).Final R=0.044 for 4301 reflections with I≥3σ(I).This compound may be regarded as a mixed-valent trinuclear molybdenum cluster{Mo_2(V)Mo(Ⅳ)(μ_3-S)(μ-S)_2- (μ-OAc)(S_2CNC_4H_8)_3(O)_2}.The Mo-Mo distances are 2.783(1),2.833(1)and 3.374(2)A in the Mo_3 non-equilateral triangle and there exist only two Mo-Mo bonds.The cluster was obtained by oxi- dation and ligand substitution of{Mo_3(μ_3-S)(μ-S)_3[μ-S_2P(OEt_2)][S_2P(OEt)_2]_3(H_2O)}.

Molybdenum carbide clusters for thermal conversion of CO2 to CO via reverse water-gas shift reaction

Molybdenum carbides are highly active for CO2 conversion to CO via the reverse water-gas shift(RWGS)reaction, however the large grain size up to micrometers renders its relatively lower active sites utilization efficiency while generating CH4 as a by-product. In this work, a homogeneously dispersed molybdenum carbide hybrid catalyst with sub-nanosized cluster(the average size as small as 0.5 nm) is prepared via a facile carbothermal treatment for highly selective CO2-CO reduction. The partially disordered Mo2C clusters are characterized by synchrotron high-resolution XRD and atomic resolution HAADF-STEM analysis, for which the source cause of the disorder is pinpointed by XAFS analysis to be the nitrogen intercalants from the carbonaceous precursor. The partially disordered Mo2C clusters show a RWGS rate as high as 184.4 μmol gMo2C-1s-1 at 400 ℃ with a superior selectivity toward CO(> 99.5%). This work 2 highlights a facile strategy for fabricating highly dispersed and partially disordered Mo2C clusters at a sub-nano size with beneficial N-doping for delivering high catalytic activity and operational stability.

Synthesis, Structural Characterization and Reactivity of Two New Triangular Molybdenum Cluster Compounds: Mo_3Te_7-[S_2CN(CH_2CH_2OH)_2]_3I and Mo_3Te_4Y_3[S_2P( ~iPrO)_2]_3I (Y_3=1.43Te+1.57S)

Two triangular molybdenum-tellurium clusters, Mo_3Te_7-[S_2CN(CH_2CH_2OH)_2]_3I (1) and Mo_3Te_4Y_3[S_2P(~iPrO)_2]_3I (Y_3 = 1. 43Te+ 1.57S) (2), were obtainedfrom the reaction of K·HOdtc [HOdtc = S_2CN(CH_2CH_2OH)_2] or K·~iPr_2dtp (~iPr_2dtp =S_2P[OCH(CH_3)_2]_2) with a mixed product of elements Mo, Te(S) and I_2 at high temperature. Thestructures of the two compounds were determined by X-ray crystallography study. Crystal data are,(1): monoclinic, P2_1/n, a = 1.6256(3), b = 1.3264(2), c = 1.8808(4) nm, β = 96.923°, V = 4.025.9(14) nm^3, D_(cal) = 3.050 g·cm^(-3), Z = 4, and (2): monoclinic, P2_1/n = 1.4564(2), b =2.3917(4), c = 1.5094(3) nm, β= 114.35(2)°, V = 4.0259(14) nm^3, D_(cal) = 2.449 g·cm^(-3) and Z= 4. Single crystal analyses show that 1 consists of discrete Mo_3Te_7[S_2CN(CH_2CH_2OH)_2]_3Iconnected into three-dimensional framework via hydrogen bonds, while 2 forms a linear chain viaTe(S)―I interaction.

Theoretical study of small Mo clusters and molecular nitrogen adsorption on Mo clusters

This paper studies the small molybdenum clusters of Mon （n=2 8） and their adsorption of N2 molecule by using the density functional theory （DFT） with the generalized gradient approximation. The optimized structures of Mon clusters show the onset of a structural transition from a close-packed structure towards a body-centred cubic structure occurred at n = 7. An analysis of adsorption energies suggests that the Mo2 is of high inertness and Mo6 cluster is of high activity against the adsorption of N2. Calculated results indicate that the N2 molecule prefers end-on mode by forming a linear or quasi-linear structure Mo-N-N, and the adsorption of nitrogen on molybdenum clusters is molecular adsorption with slightly elongated N-N bond. The electron density of highest occupied molecular orbital and lowest unoccupied molecular orbital, and the partial density of states of representative cluster are also used to characterize the adsorption properties of N2 on the sized Mon clusters.

Synthesis and Crystal Structure of an Incomplete Cubane-like Heterobimetallic Cluster [（η^5-C5Me5）2Mo2（μ3-S）（μ-S）3（CuCl）]

The reaction of[（η^5-C5Me5）2Mo2（μ3-S）（μ-S）3（CuCl）]1 with Na2S in MeCN produced a trinuclear cluster [（η^5-C5Me5）2Mo2（μ3-S）（μ-S）3（CuCl）] 2. 2 crystallizes in the monoclinic system, space group P21/c with a = 15.563（3）, b = 8.9547（18）, c = 17.846（4） A, β = 101.29（3）°, V = 2438.9（9） A^3, Z = 4, Dc = 1.878 g/cm^3, T = 193（2） K, C20H30ClCuMo2S4, Mr = 689.60, F（000） = 1376, μ（MoKa） = 2.335 mm ^-1, S = 1.050, R = 0.0305 and wR = 0.0688 for 4033 observed reflections with I 〉 20-（I）. In the structure of 2, one [（η^5-C5Me5）2Mo2（μ-S）2S] moiety and one CuCI unit are assembled into an incomplete cubane-like [Mo2S4Cu] core framework, in which the Cu center adopts a distorted tetrahedral geometry coordinated by one ,μ3-S atom, two μ-S atoms and one terminal chloride. The two Mo…Cu contacts are 2.7519（7） and 2.7689（8） A, respectively.

Synthesis and Crystal Structure of a Mo-S Cluster Compound Coordinated by Isonicotinate

A cluster compound, Mo3S4（DTP）3（IN）（Py）·EtOH I （DTP = diethyl dithiophosphate, IN = isonicotinate） has been rationally synthesized and characterized by single-crystal X-ray diffraction. The crystal belongs to the triclinic system, space group P1 with a = 13.6345（2）, b = 13.7805（2）, c = 14.5400（1）A, α = 107.078（1）, β = 113.380（1）, γ = 96.310（1）°, C25H45Mo3- N2O9P3S10, Mr = 1218.96, V = 2315.75（5） A^3, Z = 2, Dc = 1.748 g/cm^3, μ = 1.399, F（000） = 1224, R = 0.0425 and wR = 0.1144 for 6335 observed reflections （I 〉 2σ（I））. 31^P NMR spectrum has been measured with the resonance 110.050 and 108.783 （2：1）.

Study on the Magnetic Properties of MoFe_3S_4 Single Cubane-like Clusters Containing R_2dtc Ligands

Both cubane-like clusters MoFe_3S_4 (Me_2dtc)_5·2CH_2Cl_2 (1) and MoFe_3S_4(C_4H_8dtc)_5·2EtCN (2) were used to study the temperature-dependent behavior of the molar magnetic susceptibility. A spin coupling model was suggested and the fitting results agree with the model and structural and spectroscopic parameters.

DFT Study on the Electronic and Structural Properties of MoS_6^(-/0) Clusters

Density functional theory （DFT） calculations are employed to investigate the structural and electronic properties of MoS6^- and MoS6 clusters. Generalized Koopmans＇ theorem is applied to predict the vertical detachment energies and simulate the photoelectron spectra （PES）. Intriguingly, the terminal S2-, polysulfide S2^2- and S3^2- ligands simultaneously emerge in the lowest-energy structure of MoS6. Molecular orbital analyses are performed to analyze the chemical bonding in MoS6^-/0 clusters and elucidate their structural and electronic properties.

Synthesis and Crystal Structure of an Incomplete Cubane-type Mo_3S_4 Cluster with the N-N-O Type Tridentate Ligand: {Mo_3S_4[NH_2CH_2CH(O)CH_2NH_2]_3}(DTP)·(H_2O)_2·(DMF)

A new cluster {Mo3S4[NH2CH2CH(O)CH2NH2]3}(DTP)?(H2O)2?(DMF) (DTP = diethyldithiophosphate) has been synthesized via ligand substitution reaction of Mo3S4(DTP)4(H2O) with an alkaline ligand 1,3-diamino-2-propanol(DAPROH) in a mixed organic solvent, and its crys- tal structure was determined with the following data: Mo3S6PC16H48O8N7, Mr = 977.76, triclinic, space group P1, Z = 2, a = 10.319(2), b = 12.843(3), c = 15.335(3) ?, α = 65.26(3), β = 82.18(3), γ = 70.67(3)o, V = 1741.7(6) ?3, Dc = 1.864 g/cm3, μ = 1.517 mm-1, F(000) = 988, the final R = 0.0794 and wR = 0.2111 for 6318 observed reflections (I>2σ(I)). The structure analysis indicates that all DTP ligands of Mo3S4(DTP)4(H2O) are replaced and each DAPRO molecule acts as a tri- dentate ligand chelating to each Mo atom of the Mo3S4 core. Different from the precursor, the clus- ter symmetry is elevated to C3. In addition, the UV-spectrum of the title compound was measured.

Synthesis and Crystal Structure of a New Dimolybdenum(V) Complex Na_4[Mo_2O_4(HNTA)_2]_2·19H_2O

The new binuclear molybdenum（V） complex Na4[Mo2O4（HNTA）2]2·19H2O （NTA = nitrilotriacetate） has been prepared and characterized by single-crystal X-ray diffraction analysis and IR. The crystal has space group Pnma with a = 10.2239（2）,b = 23.8174（3）,c = 23.1845（4） A,V = 5645.58（16）A^3,Z = 4,C24H66Mo4N4Na4O51,Mr = 1702.50,Dc = 1.958 g/cm^3,μ = 1.027 mm^-1,F（000） = 3280,T = 293（2） K,the final R = 0.0609 and wR = 0.1449 for 5512 observed reflections （I 〉 2σ（I））. Each MoV atom has a distorted octahedral coordination geometry,and the two coordination octahedra share a common edge to form a dioxo-bridged Mo2O4 unit which is coordinated by NTA ligands. The dianionic binuclear units [Mo2O4（HNTA）2]^2- are interconnected by Na^＋ into a layered structure.

Probing Diverse Disulfur Ligands in the Mo_2S_n^(–/0)(n = 4 ～ 8) Clusters: Structural Evolution and Chemical Bonding

Density functional theory （DFT） and coupled cluster theory （CCSD（T）） calcula-tions were employed to investigate the geometric and electronic structures of a range of dinuclearmolybdenum sulfide clusters, Mo2S,- and Mo2S,^-/0（n = 4-8）. The results showed that the sulfuratoms tended to occupy the terminal sites of the clusters continuously in the process of sequentialsulfidation. After the oxidation state of Mo atoms reached the maximum of ＋6, diverse disulfurligands emerged in the sulfur-rich Mo2S^-/0 （n = 7,8） clusters. The driving forces of removing asulfur atom from different S ligands in Mo2S^-/0 （n = 4-8） clusters, especially from those disulfurunits, were evaluated. The corresponding order may provide insight into the pretreatment of freshMoS2 catalysts. Vertical detachment energies （VDEs） were predicted according to the GeneralizedKoopmans＇ theorem, and then the photoelectron spectra （PES） were simulated. Molecular orbitaland spin density values were analyzed to elucidate the chemical bonding and the evolutionarybehavior in the dinuclear molvbdenum sulfide clusters.

Synthesis and Crystal Structure of a New Mo/Au/S Cluster [Et_4N][Mo_2S_4(AuPPh_3)(edt)_2]· 0.25Et_2O·0.25MeOH(edt=Ethanedithiolate)

Reactions of the preformed cluster precursor [Et4N]2[Mo2S2（μ-S）2（edt）2] （edt = ethanedithiolate） （1） with [Au（PPh3）Cl] in MeOH/MeCN gave rise to a new heterobimetallic Mo/Au/S cluster [Et4N][Mo2S4（AuPPh3）（edt）2]·0.25Et2O·0.25MeOH （2·0.25Et2O·0.25MeOH）. It was characterized by elemental analysis, IR spectrum and X-ray analysis. 2·0.25Et2O·0.25MeOH crystallizes in the monoclinic system, space group C2/c with a = 20.117（4）, b = 9.2705（19）, c = 44.418（9） A^°, β= 93.19（3）°, V = 8271（3） A^°^3, Z = 8, Dc = 1.794 g/cm^3, T = 193 K, C31.25H43AuMo2NO0.50PS8, Mr = 1116.96, F（000） = 4380, μ（MoKa） = 4.603 mm^-1, S = 1.019, R = 0.0672 and wR = 0.1708 for 7243 observed reflections with I 〉 2σ（I）. The anion of 2 consists of a butterfly-shaped Mo2S4Au core in which one [AuPPh3]^＋ cation is coordinated by one bridging S and two terminal S atoms of the [（edt）2Mo2（S）2（μ-S）2] moiety. The Au（I） center adopts a pseudo-tetrahedral coordination geometry, and the Au-S bond lengths vary from 2.425（2） to 2.898（3）A^°.

豫西地区金钼铅锌银矿集区成矿规律研究

豫西地区金钼铅锌银矿集区是我国多金属矿产资源的重要产地,属于东秦岭大型成矿带的东段。以金矿床及银铅矿为代表阐述了金钼铅锌银热液矿床的成矿规律(包括分布规律、矿床物质来源、矿床成因及花岗岩的成矿作用等内容),分析了矿床与构造的关系、地层物质组成的关系及与花岗岩之间的关系等,得出矿床的分布具丛聚性,而且矿集区具有小岩体成大矿的规律(金堆城钼矿、南泥湖钼矿、东沟钼矿、文峪金矿、东闯金矿),矿床成矿物质均来源于基底地层。燕山期花岗岩是各种矿产的高温高压热源的提供者,岩浆期后含矿热液为成矿物质向围岩及构造进行广泛充填、交代和沉淀成矿的关键载体。