Synthesis and structural characterization of a novel dimolybdenum(I) compound with mixed‐tribridging ligands: [Bu4N][Mo2(μ‐SPh)2(μ‐Cl(CO6]

A novel mixed‐tribridged dimolybdenum(I) compound [Bn₄N][Mo₂(μ‐SPh)₂(μ‐Cl)(CO)₆] (1) has been synthesized from the reaction of Mo₂(CO)₃(SPh)₂ with BU₄NCl. Compound 1 was characterized by IR, UV‐Vis and ¹H, ¹³C, ⁹⁵Mo NMR spectroscopic analyses. The electrochemical behavior was measured by cyclic voltammetry, indicating a quasi‐reversible two‐electron transfer in one step. The crystal structure determined by X‐ray crystallography shows that 1 contains a [Mo₂(μ‐S)₂(μ‐Cl)]^? core with a planar Mo₂S₂unit and a Cl bridge. The Mo? Mo distance is 0.28709(7) nm, and the Mo‐Cl‐Mo angle is 66.44(4)°. A newface‐sharing bioctahedral structure is discussed.     

A New Organic‐Inorganic Charge‐transfer Salt [C15H17N4]4[Mo8O26] — Synthesis,Properties and Crystal Structure

A new organic donor 3‐amino‐6‐dimethylamino‐2‐methyl‐phenazine was introduced to charge‐transfer complex with polyoxometalate. The complex [C₁₅H₁₇N₄]₄[Mo₈O₂₆] ( 1 ) was synthesized by hydrothermal reaction of neutral red chloride (3‐amino‐6‐dimethylamino‐2‐methyl‐phenazine hydrochloride) and (NH₄)₆[Mo₇O₂₄] · 4H₂O and was characterized by EPR, element analysis and single crystal x‐ray diffraction.     

Synthesis and Characterization of a One- dimensional Molybdenum Oxide （H2enMe）[Mo3O10]

A hybrid organic-inorganic material (H2enMe)[Mo3O10] (C3H12Mo3N2O10, Mr = 523.97) has been synthesized under hydrothermal conditions and its crystal structure was determined by X-ray diffraction. It crystallizes in the orthorhombic system, space group Pnma with a = 12.430(2), b = 7.6089(12), c = 11.9553(19) , V = 1130.7(3) 3, Dc = 3.078 g/cm3, Z = 4, μ(MoKa) = 3.328 mm1, F(000) = 1000, the final R = 0.0256 and wR = 0.0716 for 1314 observed reflections with I > 2σ(I). A total of 11780 reflections were measured and 1325 were unique (Rint = 0.0244). It consists of infinite one-dimensional edge-sharing MoO6 octahedral chains with [Mo3O10]2 moieties. The protonated diaminopropane cations are located between the chains and linked to the oxygen atoms of the inorganic skeletal backbones by hydrogen bonds. It is indicated that the as-synthesized compound displays photochromic property in the solid state.     

Intermediate molybdenum oxides involved in binary and ternary induced electrodeposition

The first stages of Co–Ni and Co–Ni–Mo deposition in sulphate–citrate medium at pH 4.0 were analysed. In both cases, the formation of non-hydrogenated nickel on the electrode before alloy deposition was detected by linear sweep voltammetry and inductively coupled plasma mass spectrometry. Co–Ni electrodeposition was anomalous since the Co/Ni ratio in the alloy was higher than the corresponding [Co(II)]/[Ni(II)] ratio in solution. The adsorption of Co(II) over the initial nickel could explain the anomalous codeposition, which persisted with the addition of molybdate to the Co–Ni bath. However, the formation of intermediate molybdenum oxides also took place. A mechanism has been proposed to describe the sequence of steps for Co–Ni–Mo electrodeposition. Under our conditions, the alloy is formed mainly from free Co²⁺ and Ni²⁺ cations, whereas molybdate is reduced firstly to molybdenum oxide from MoO₄(H₃Cit)²⁻ and, secondly, NiCit⁻ catalyses the subsequent reduction to molybdenum metal of the intermediate [MoO₂–NiCit⁻]_ads species.     

The exclusive formation of cyclopentenones from molybdenum hexacarbonyl-catalyzed Pauson-Khand reactions of 5-allenyl-1-ynes

The exclusive formation of cyclopentenones (via path B) was observed in molybdenum hexacarbonyl (10 mol %) catalyzed Pauson-Khand reactions of 1,6-allenynes under 1 atm of CO (balloon) without any substitutent effect.     

Texture of molybdenum thin films on SrTiO3(1 0 0): A RHEED study

The structure of ultrathin Mo films on SrTiO₃(1 0 0) was studied by in situ reflection high-energy electron diffraction (RHEED). A different structure was observed for films less than 20 Å thick than for thicker films. These films were epitaxial and had a metastable structure. Thicker films had the dimensions of equilibrium bcc Mo(1 1 0). Relaxation processes transformed the metastable Mo into bcc Mo, resulting in the following orientation relationships between Mo and SrTiO₃: (1 1 0)[0 0 1]_bcc Mo ∥ (1 0 0)[0 0 1]_SrTiO3 and (1 1 0)[1 1 1]_bcc Mo ∥ (1 0 0)[0 1 1]_SrTiO3. The formation of such specific orientations is related to transformations via the Bain and Needle Path, respectively.     

某些9—取代苯基荧光酮类试剂与钼（Ⅵ）显色反应的研究

研究了在表面活性剂存在下，三种新的９－取代苯基荧光酮类试剂与钼（Ⅵ）的显色反应及其光度分析特征，试验结果表明，试剂分子９位上引入的取代基明显影响试剂的配合能力。本文从取代基的电子效应等方面讨论了试剂的结构与性能之间的关系。     

Heterometallic cuboidal complexes as derivatives of the [MO3S4(H2O)9]4+ cluster

Heterometallic atoms can be incorporated into the Mo ₃ ^IV trinuclear ion [Mo₃S₄(H₂O)₉]⁴⁺ to give cuboidal complexes of the kind Mo₃MS₄, or related edge-linked species {Mo₃MS₄}₂, or corner-shared Mo₃S₄MS₄Mo₃ double cubes, depending on the heteroatom used. All of the products formed can be obtained as aqua ions. With four recent additions there are now 15 different heterometal atoms participating in this chemistry from Cr in Group 6 to Bi in Group 15. Preparative procedures, X-ray crystal structures, and distinctive properties including UV-Vis spectra, elution characteristics using Dowexcation exchange chromatography, ICP metal analyses, and the stoichiometries of reactions in which the heterometallic product is oxidized back to [Mo₃S₄(H₂O)₉]⁴⁺ (with release of the heterometal in an ionic form) are considered.Dedicated to Professor Jiaxi Lu on the occasion of his 80th birthday.     

Structure/property relationship of Schrock-type alkylidene complexes based on tungsten and molybdenum

The structure/property relationship of Schrock-type alkylidene complexes with tungsten and molybdenum as central atoms was investigated. Terminal and, E and Z internal olefins as well as double bond substituted and unsubstituted unsaturated polymers served as metathesis substrates. According to the results obtained, it is possible to choose the optimal catalyst depending on the metathesis substrate and temperature, the central atom plays a decisive role. Examples concerning equilibrium polymerization demonstrate the practical utilization.     

二溴羟基苯基荧光酮荧光熄灭法测定微量钼

本文用荧光熄灭法研究了十溴羟基苯基荧光酮(DBH-PF)-溴化十六烷基三甲铵(CTMAB)-Mo(Ⅵ)体系的测定方法及条件。在0.002～0.008mol/L的H_3PO_4介质中,在CTMAB存在下,钼(Ⅵ)与试剂形成1:2的桔红色络合物,其最大激发波长为470nm和502nm,最大发射波长为520nm。钼在0.03～0.50μg/25ml范围内具有线性关系,检出限为0.03μg/25ml。本法灵敏度高,选择性好,用于检测合金钢中的微量钼,结果满意。