Synthesis, Crystal Structure, UV-vis and EPR Studies of（ NH3CH2CH2NH2 ） 2.5 [ Mo0.5^（V）W0.5^（VI）O2 （ OC6H4O ） 2]

Cis-dioxo-metal complex ( NH3CH2CH2NH2 ) 2.5 [ Mo0.5^(V)W0.5^(VI)O2 ( OC6H4O ) 2] 1 was obtained by the reaction of tetra-butyl ammonium hexamolybdotungstate with 1, 2-dihydroxybenzene in the mixed solvent of CH3OH, CH3CN and ethylenediamine,and characterized by X-ray diffraction, UV-vis and EPR analysis. Compared with its analogous complexes (NH3CH2CH2NH2)3[Mo^(V)O2(OC6H40)2] 2 and (NH3CH2CH2NH2)2[W^(VI)O2(OC6H4O)2] 3, the results show that tungsten(VI) is less active in redox than molybdenum (VI) and that the change of the valence induced by substitution of W(VI) for Mo(V) in EMO2(OC6H40)2]n- does not influence the coordination geometry of the complex anion in which the metal center exhibits distorted octahedral coordination with cis-dioxo catechol. The responses to EPR of complexes 1 and 2 are active but complex 3 is silent,and the UV-vis spectra exhibited by the three complexes are obvious different because of the different electronic configuration between the central Mo(V) and W(VI) ions in the complexes.It is noteworthy that complexes 1 and 2 have the similar EPR signal to flavoenzyme, suggesting that the three complexes have the same coordination geometry feature with the co-factor of flavoenzyme.     

Interactions with ATP, DNA Cleavage and Anti-tumor Activities of Complexes with Anions [Mo（V）O2（O2CeH4）2]^3-, [Mo（Ⅴ）0.5W（Ⅵ）0.5O2（O2C6H4）2]^2.5- and [W（Ⅵ）O2（O2C6H4）2]^2-

(NH3CH2CH2NH2)3[Mo(Ⅴ)O2(O2C6H4)2] (1), (NH3CH2CH2NH2)2.5[Mo(Ⅴ)o.sW(Ⅵ)o.502(O2C6H4)2] (2) and(NH3CH2CH2NH2)2[VC(Ⅵ)O2(O2C6H4)2] (3) were synthesized, structurally characterized by X-ray diffraction analysis, and studied on their interactions with ATP, their DNA cleavage activities and antitumor properties. The redox state of molybdenum was not changed on going from crystal to aqueous solutions in complexes 1 and 2, while tungsten underwent reduction from W(VI) to W(V) in complexes 2 and 3. ATP promoted the oxidation of both molybdenum and tungsten from M(Ⅴ) to M(Ⅵ) and the hydrolysis of catecholate ligands in solution consisting of ATP and the complexes. Complex 1 possesses fairly good activity to DNA cleavage and against tumor S180 in mice, and is more effective than the control drug cyclophosphamide under the identical conditions. However, complexes 2 and 3 exhibited marginal effectiveness. The effectiveness of anti-tumor of the complexes was related positively to their DNA cleavage activities and their hydrolysis of catecholate ligands.     

Syntheses, Structures and Characterizations of Two New Vanadium(V) Complexes: [PyH][V~vO_2(C_(14)H_9N_2O_3Br)] and [V~vO(C_(14)H_9N_2O_3Br)(OCH_3)]

<正>The new oxovanadium (V) complex, [PyH][VO2(L)] 1 (salicyladehyde 5-bromo salicyloylhydrazone is abbreviated as H2L; Hpy is protonated pyridine) was obtained from a refluxed solution of VOSO4 and H2L in acetonitrile-methanol-pyridine. Similarly, another new complex, [VO(L)(OCH3)] 2 was synthesized by refluxing VOSO4 and H2L in methanol-pyridine. Crystal data for 1: C19H15N3O5BrV, Mr= 496.2, monoclinic, P21/n, a = 7.1885(3), b = 9.2718(3), c = 28.803(1) A, β = 96.185(1)°, Z = 4 and V = 1908.6(1) A3; for 2: C15H12N2O5BrV, Mr= 431.1, monoclinic, P2,/n, a = 12.202(2), b = 8.045(2), c = 16.604(3) A, β = 101.29(3)°, Z = 4 and V = 1598.4(2) A3. The structures of 1 and 2 have been determined by X-ray analyses and reveal that the coordination environments of V atoms in both complexes are of square-based pyramid. Three of the four based donor atoms are from the tridentate "ONO" donor ligand while the fourth is one terminal oxygen atom with the V(1) - O(3) distance 1.646(4) A for 1 and one -OCH3 group with the V     

^31P NMR Studies on the Ligand Dissociation of Trinuclear Molybde-num Cluster Compounds

A series of carboxylate-substituted trinudear molybdenum dus-ter compounds formulated as Mo3S4(DTP)3(RCO2)(L), where RffiH, CH3, C2H5, CH2Cl, CCl3, R^1C6H4(R^1 is the group on the benzene ring of aromatic carboxylate ), L=pyridine,CH3CN, DMF, have been synthesized by the ligand substitu-tion reaction. The dissociation of the loosely-coordinated ligand L from the cluster core was studied by ^31p NMR. The dissocia-tion process of L is related to the solvent, temperature, and acidity of carboxylate groups, so as to affect the solution struc-ture and reactive properties of the duster. The long-distance in-teraction between ligands RCO2 and L is transported by Mo3S4 core.     

Structural and Spectroscopic Studies on [Cu（DACH）2（H2O）]—Cl2（DACH—1,4—Diazacycloheptane）

A penta-coordinated Cu(Ⅱ） complex with 1,4-diazacycloheptane (DACH),[Cu(DACH)2(H2O)]Cl2(1),has been synthesized and characterized by X-ray diffraction,IR spectra,elemental analyses,thermal analyses,UV-Vis and ESR techniques.Complex 1 crystallizes in orthorhombic crystal system,Pbcn space group with a=1.6075(4),b=1.0539(3),c=0.9195(3)nm,V=1.5578(7)nm^3,Mr=352.79,Z=4,Dc=1.487g/cm^3,final R=0.0451 and wR=0.1294.The structure of 1 indicates that the central Cu(Ⅱ） atom is penta-coordinated by four nitrogen aboms of two DACH moieties at the equatorial positions and a water molecule at the axis position.The coordination geometry of Cu(Ⅱ） could be considered as an approximately ideal square-pyramidal environment.Both DACH rings arrange in cis-form and are predominantly in the boat-boat conformation (80%) with some disorder to the chair-chair conformation (20%).The Cl^- anions are hydrogen bonded with the nitrogen donors of the DACH rings and the oxygen donor of the coordinated H2O molecule to form a one-dimensional zigzag linear structure. The solution behaviors of 1 are also discussed in detail by Uvvis and ESR technique.     

水杨醛酪氨酸铜配合物合成和EPR波谱

A new Schiff base derived from tyrosine and salicylidene and its copper(Ⅱ) complex have been synthesized and characterized by elemental analyses,molar conductances,thermal analyses,infrared spectra,electronic spectra and EPR spectra.The composition of the complex is K[CuL(Ac)]•H2O, where L=H13C16NO4. EPR spectra of the copper(Ⅱ) complex were investigated in various solvents at different temperatures.It is found that the linewidth of four hyperfine lines on solution spectra at room temperature is unequal and changes with mⅠ ,this could be satisfactorily explained by the relaxation effect.The relaxation time and the relaxation rate were calculated.By using spectral parameters from solution spectra at low temperature,the bonding parameters of Cu(Ⅱ) complex were calculated.The bonding characterization and stability of the complex were disscussed.The results show that the in plane 螵瞓ond and the in plane 皙瞓ond in the complex all play an important role.     

Effect of Solvents on Oxidation of 1, 1′-Bi-2-naphthol

A novel biomimetic catalyst of complex Cu (p-OTs)2/ethanolamine (1 : 1 ) was used to oxidize 1, 1′-bi-2naphthol into xanthene derivatives with a relative high yield in a mixed solvents of dimethyl sulfoxide (DMSO) and CH3OH. The studies on the effect of some solvents on the yield of xanthene derivatives indicates that the yield reduces dramatically with the increase of the content of H2O in the mixed solvents of H2O and DMSO. No product can be obtained when the content of H2O is up to 70%. The cyclic voltammetric study demonstrated that the copper ion in complex Cu(p-OTs)2/ethanolamine(1:1) is reduced via a twostep one-electron reduction process from Cu (Ⅱ) to Cu in the mixture of DMSO and H2O. Water as a poor solvent in respect to the reactants probably hampered the coordination of 1, 1′-bi-2-naphthol to copper/amine complex and led to the insufficient catalytic efficiency of complex Cu(p-OTs),/ethanolamine(1:1).     

XPS Characterization of Carbon Nanotube Supported CoMo Hydrodesulfurization Catalysts

In this paper, the effect of catalytic support and sulfiding method on the chemical state of supported Co-Mo catalysts is studied by XPS. After sulfidation with in-situ method, the majority of molybdenum in CNT supported CoMo catalyst is transferred to a species with a formal chemical state Mo(Ⅳ) in MoS2 phase, and the rest to Mo(Ⅴ) which consists of Mo coordinated both to O and S, such as MoO2S2^2- and MoO3S^2-. In case of CoMo/γ-Al2O3 catalyst sulfided with in-situ method, a fraction of molybdenum is transferred to formal state Mo(Ⅳ) in the form of MoS2, but there is still a mount of unreduced Mo(VI) phase which is difficult to be sulfided. In CoMo/CNT catalyric system sulfided with ex-situ method, Mo(IV) in the form of MoS2 is detected along with a portion of unreduced Mo(VI) phase, suggesting that not all the Mo phases are reduced and sulfided by ex-situ method. As for CoMo/γ-Al2O3, a portion of molybdenum is sulfided to intermediate reduced state Mo(V) which consists of Mo coordinated both to O and S, such as MoO2S2^2- and MoO3S^2-, in addition, there is still a fraction of unreduced Mo(Ⅵ)phase. XPS analyses results suggest that CNT support facilitates the reduction and sulfidation of active species to a large extent, and that alumina support strongly interacts with active species, hereby producing a fraction of phase which resists complete sulfiding. Catalytic measurements of catalysts in the HDS of dibenzothiophene (DBT) show that CoMo/CNT catalysts are of higher HDS activity and selectivity than CoMo/γ-Al2O3 catalyst, which is in good relation with the sulfiding behavior of the corresponding catalyst.     

Synthesis of Substituted Indenyl Lanthanide Chloride and Molecular Structure of[（C5H9C9H6）2Yb（μ—Cl）2Li（Et2O）2]

Reaction of anhydrous ytterbium trichlorides with 2 equiv.of cyclopentylindenyl lithium in THF solution,followed by removal of the solvent and crystallization of the porduct from diethyl ether,affords a crystal complex of the composition(C5H9C9H6)2Yb(μ-Cl)2Li(Et2O)2.Crystallographic analysis shows that the ytterbium coordinated by two cyclopentylindenly rings and lithium surrounded by two ether molecules are bridged by the two chlorine atoms and Yb,Li and two chlorine atoms form a plane.     

One—dimensional Zigzag Chain Coordination Polymer [Zn（μ—phth）（imi）2]∞ Bridged by o—Phthalato

The reaction of zinc carbonate with o-phthalic acid and imidazole in an aqueous-alcohol solution led to the formation of colorless crystals of [Znμ-phthimi2]∞. Single-crystal X-ray analysis has revealed that the complex crystallizes in a monoclinic system, space group Pn with a = 8.394(2), b = 9.976(3), c = 9.959(3)A, β = 104.409(4)°, V = 807.6(4)A3, Z = 2, C14H12N4O4Zn, Mr = 365.6(5), Dc = 1.504 g/cm3, μ = 1.544 mm-1, F000 = 372, the final R = 0.0466 and wR = 0.1171 for 1834 reflections with I>2σ(I). The complex displays a zigzag infinite chain structure in which each zinc(Ⅱ)center is coordinated by two oxygen atoms and two nitrogen atoms to generate a ZnN2O2 distorted tetrahedral geometry. The neighboring zinc atoms are bridged by the o-phthalate ligand. Each chain is linked by hydrogen bonds with its neighbors to form a three-dimensional coordination polymer.     

p-tert-Butylcalix[4]arene complexes of molybdenum and tungsten: reactivity of the calixarene methylene C-H bond and the facile migration of the metal around the phenolic rim of the calixarene

p-tert-Butylcalix[4]arene, [CalixBut(OH)4], reacts with Mo(PMe3)6 and W(PMe3)4(eta2-CH2PMe2)H to yield compounds of composition {[CalixBut(OH)2(O)2]M(PMe3)3H2} which exhibit unprecedented use of a C-H bond of a calixarene methylene group as a binding functionality in the form of agostic and alkyl hydride derivatives. Thus, X-ray diffraction studies demonstrate that, in the solid state, the molybdenum complex [CalixBut(OH)2(O)2]Mo(PMe3)3H2 exists as an agostic derivative with a Mo...H-C interaction, whereas the tungsten complex exists as a metallated trihydride [Calix-HBut(OH)2(O)2]W(PMe3)3H3. Solution 1H NMR spectroscopic studies, however, provide evidence that [Calix-HBut(OH)2(O)2]W(PMe3)3H3 is in equilibrium with its agostic isomer [CalixBut(OH)2(O)2]W(PMe3)3H2. Dynamic NMR spectroscopy also indicates that the [M(PMe3)3H2] fragments of both the molybdenum and tungsten complexes [CalixBut(OH)2(O)2]M(PMe3)3H2 migrate rapidly around the phenolic rim of the calixarene on the NMR time scale, an observation that is in accord with incorporation of deuterium into the methylene endo positions upon treatment of the isomeric mixture of [CalixBut(OH)2(O)2]W(PMe3)3H2 and [Calix-HBut(OH)2(O)2]W(PMe3)3H3 with D2. Treatment of {[CalixBut(OH)2(O)2]W(PMe3)3H2} with Ph2C2 gives the alkylidene complex [CalixBut(O)4]W=C(Ph)Ar [Ar = PhCC(Ph)CH2Ph].     

Structural, electrochemical and oxygen atom transfer properties of a molybdenum selenoether complex [Mo2O4(OC3H6SeC3H6O)2] and its thioether analogue [Mo2O4(OC3H6SC3H6O)2

The first crystallographically characterized molybdenum(vi) selenoether complex [Mo(2)O(4)(OC(3)H(6)SeC(3)H(6)O)(2)] and its thioether analogue [Mo(2)O(4)(OC(3)H(6)SC(3)H(6)O)(2)] were synthesised. Their structural, electrochemical and oxygen atom transfer properties are compared. This is relevant for the molybdenum cofactors of the DMSO reductase family where the coordination of the active site metal occurs through O (serine/aspartate), S (cysteine) or Se (selenocysteine). Both structures are almost identical except for those parameters that are directly derived from the different sizes of the varied ligand atoms (Se and S). No trans influence was observed. The metal centered redox process (Mo(V)<-->Mo(VI)) is at slightly lower voltage for the sulfur than for the selenium complex. The selenium compound catalyses the oxygen atom transfer from DMSO to PPh(3) by a different mechanism and at a higher rate than the sulfur compound, which is an indication that cysteine and selenocysteine might be used for a purpose in the different molybdenum and tungsten cofactors.     

Dioxotungsten 1,2-benzenedithiolate complex stabilized by NH...S hydrogen bonds

Novel dioxo-tungsten(VI) bis(1,2-benzenedithiolate) complexes with neighboring amide groups, as models for tungsten enzymes, (NEt4)2[W(VI)O2{1,2-S(2)-3,6-(RCONH)2C6H2}2] (R = CH3, t-Bu), were designed and synthesized. The presence of the NH...S hydrogen bond was confirmed through IR spectrometry and X-ray crystallographic analysis. In the W(VI)O2 complexes, the NH...S hydrogen bond trans to the oxo ligand is stronger than that cis to oxo. On the basis of comparisons with [W(VI)O2(1,2-S2C6H4)2](2-), the NH...S hydrogen bond positively shifted the W(VI)/W(V) redox potentials and depressed the reduction by benzoin or triphenylphosphine. These results suggest that the NH...S hydrogen bond stabilizes the oxo ligand through trans influence and regulates O-atom transfer in tungsten and molybdenum enzymes.     

Dimeric dioxomolybdenum(VI) and oxomolybdenum(V) complexes with citrate at very low pH and neutral conditions

A novel dimeric dioxomolybdenum(VI) citrate complex, K[(MoO2)2-(OH)(H2cit)2].4H2O (1), with weak coordination of beta-carboxylic acid groups and the first structural example of an oxomolybdenum(V) citrate complex, (NH4)6[Mo2O4(cit)2].3H2O (2) (H4cit = citric acid), are isolated in a very acidic solution (pH 0.5-1.0) and neutral conditions (pH 7.0-8.0), respectively. Complex 1 displays strong double hydrogen bonds through beta-carboxyl and beta-carboxylic acid groups [2.621(9) A]. Transformations of the dimeric molybdenum(VI) citrate show that protonation of a carboxyl group will weaken the coordination of molybdenum(VI) citrate. There are obvious dissociations of molybdenum(VI/V) citrate complexes based on 13C NMR observations in solution.     

The reduction of tris-dithiolene complexes of molybdenum(VI) and tungsten(VI) by hydroxide ion: kinetics and mechanism

The kinetic study of the spontaneous reduction of some neutral tris-dithiolene complexes [ML3] of molybdenum(VI) and tungsten(VI), (L = S2C6H4(2-), S2C6H3CH3(2-) and S2C2(CH3)2(2-); M = Mo or W) by tetrabutylammonium hydroxide in tetrahydrofuran-water solutions demonstrates that OH- is an effective reductant. Their reduction is fast, clean and quantitative. Depending upon both the molar ratio in which the reagents are mixed and the amount of water present, one- or two-electron reductions of these tris-dithiolene complexes were observed. If Bu4NOH is present in low concentration or/and at high concentrations of water, the total transformation of the neutral M(VI) complex into the monoanionic M(V) complex is the only observed process. Stopped-flow kinetic data for this reaction are consistent with the rate law: -d[ML3]/dt = d[ML3-]/dt = k[ML3][Bu4NOH]. The proposed mechanism involves nucleophilic attack of OH- to form a mono-anionic seven-coordinate intermediate [ML3OH]-, which interacts with another molecule of [ML3] to generate the monoanionic complex [ML3]- transfering the oxygen from coordinated OH- to water. Hydrogen peroxide was identified as the reaction product. The molybdenum complexes are more difficult to reduce than their corresponding tungsten complexes, and the values of k obtained for the molybdenum and tungsten series of complexes increase as the ene-1,2-dithiolate ligand becomes more electron-withdrawing (S2C6H4(2-) > S2C6H3CH3(2-) > S2C2(CH3)2(2-)). This investigation constitutes the only well-established interaction between hydroxide ion and a tris(dithiolene) complex, and supports a highly covalent bonding interaction between the metal and the hydroxide ion that modulates electron transfer reactions within these complexes.     

Syntheses and characterization of oxygen/sulfur-bridged incomplete cubane-type clusters, [Mo3S4Tp3]+ and [Mo3OS3Tp3]+, and a mixed-metal cubane-type cluster, [Mo3FeS4ClTp3]. X-ray structures of [Mo3S4Tp3]Cl, [Mo3OS3Tp3]PF6, and [Mo3FeS4ClTp3

The reaction of [Mo3S4(H2O)9]4+ (1) with hydrotris(pyrazolyl)borate (Tp) ligands produced [Mo3S4Tp3]Cl x 4 H2O ([3]Cl x 4 H2O) in an excellent yield. An X-ray structure analysis of [3]Cl x 4 H2O revealed that each molybdenum atom bonded to the Tp ligand. We report four salts of 3, [3]Cl x 4 H2O, [3]tof x 2 H2O, [3]PF6 x H2O, and [3]BF4 x 2 H2O in this paper. The solubility and stability of the chloride salt in organic solvents differ completely from those of the other salts. We have also prepared a new compound, [Mo3OS3Tp3]PF6 x H2O ([4]PF6 x H2O), via the reaction of [Mo3OS3(H2O)9]4+ (2) with KTp in the presence of NH4PF6. All the molybdenum atoms bonded to Tp ligand. 1H NMR signals corresponding to nine protons bonded to three pyrazole rings in one Tp were observed in a spectrum (at 253 K) of [3]BF4 x 2 H2O. It shows that cluster 3 has a 3-fold rotation axis in CD2Cl2 solution. Twenty-one 1H NMR signals corresponding to twenty-seven protons bonded to nine pyrazole rings in three Tp ligands were observed in a spectrum (at 233 K) of [4]PF6 x H2O; obviously, 4 has no 3-fold rotation axis, in contrast to 3. The short CH...mu3S distance caused large upfield chemical shifts in the 1H NMR spectra of 3 and 4. The reaction of 3 with metallic iron in CH2Cl2 produced [Mo3FeS4XTp3] (X = Cl (5), Br (6)). X-ray structure analysis of 5 has revealed the existence of a cubane-type core Mo3FeS4. Complex 3 functions as a metal-complex ligand for preparing a novel mixed-metal complex even in nonaqueous solvents. The cyclic voltammogram of 5 shows two reversible one-electron couples (E(1/2) = -1.40 and 0.52 V vs SCE) and two irreversible one-electron oxidation processes (E(pc) = 1.54 and 1.66 V vs SCE).     

(NH3CH2CHNH2CH3)2[WVIO2(OC6H4O)2]的合成、晶体结构及其与ATP相互作用的NMR性质研究

在室温下, 选用具有手性特征的1,2-丙二胺(1,2-propanediamine)为对阳离子, 由正四丁基铵十钨酸盐和邻苯二酚反应, 得到了钨酶活性结构因子仿生配合物(NH3CH2CHNH2CH3)2[WVIO2(OC6H4O)2], 用单晶X射线衍射测定了其晶体结构, 晶体属单斜晶系, 空间群为P21/n, a＝1.1099(3) nm, b＝1.0416(3) nm, c＝1.8874(6) nm, β＝96.492(6)°, V＝2.1679(11) nm3, z＝4, R1＝0.0445, wR2＝0.0682; 并对它进行了IR, 1H NMR和UV-Vis谱学表征. 利用NMR研究了其与三磷酸腺苷(ATP)的相互作用, 结果发现手性特征的1,2-丙二胺及邻苯二酚苯环的1H化学位移在与ATP混合前后均呈现出较大的差异, 分析得出: 配合物中的金属离子在D2O中大多数均以W(V)价态存在, 但在与ATP共存时转化为W(VI), 并与配体发生了解离.     

Reaction of Mo(CO)_6 with Alkoxide: Synthesis and Structure of the Mo(0)-OR Complex [Et_4N]_3[Mo_2(CO)_6(μ-OC_6H_4OCH_2C_6H_5)_3]

The reaction of molybdenum hexacarbonyl with C6H5CH2OC6H4ONa and Et4NBr in CH3CN at 60 ℃ afforded the di-nuclear Mo(0) compound [Et4N]3[Mo2(CO)6(μ-OC6H4OCH2- C6H5)3] 1. 1 crystallizes in monoclinic, space group P21/c with a = 15.359(2), b = 18.378(3), c = 24.952(2), β = 102.268(4)°, V = 6882.3(16) 3, Mr = 1348.34, Z = 4, Dc = 1.301 g/cm3, F(000) = 2832 and μ = 0.424 mm-1. The final R = 0.0606 and wR = 0.1552 for 9396 observed reflections (I > 2σ(I)). 1 contains a [Mo2O3]3- core in triangular bi-pyramidal configuration and each Mo atom adopts a distorted octahedral geometry with three carbon atoms from carbonyls and three μ-O atoms from C6H5CH2OC6H4O- bridging ligands. The Mo…Mo distance is 3.30(8) , indicating no metal- metal bonding. A formation pathway via forming a di-molybdenum(0) di-bridging OR compound [Mo2(μ-OR)2(CO)8]2- has been figured out and the reaction of Mo(CO)6 with alkoxide has also been discussed.     

Reaction of Mo(CO)6 with Alkoxide: Synthesis and Structure of the Mo(0)-OR Complex [Et4N]3[Mo2(CO)6(μ-OC6H4OCH2C6H5)3]

The reaction of molybdenum hexacarbonyl with C6H5CH2OC6H4ONa and Et4NBr in CH3CN at 60 ℃ afforded the di-nuclear Mo(0) compound [Et4N]3[Mo2(CO)6(μ-OC6H4OCH2- C6H5)3] 1. 1 crystallizes in monoclinic, space group P21/c with a=15.359(2), b=18.378(3), c=24.952(2)(A), β=102.268(4)°, V=6882.3(16) (A)3, Mr=1348.34, Z=4, Dc=1.301 g/cm3, F(000)=2832 and μ= 0.424 mm-1. The final R=0.0606 and wR=0.1552 for 9396 observed reflections (Ⅰ ＞ 2σ(Ⅰ)). 1 contains a [Mo2O3]3- core in triangular bi-pyramidal configuration and each Mo atom adopts a distorted octahedral geometry with three carbon atoms from carbonyls and three μ-O atoms from C6H5CH2OC6H4O- bridging ligands. The Mo…Mo distance is 3.30(8) (A), indicating no metalmetal bonding. A formation pathway via forming a di-molybdenum(0) di-bridging OR compound [Mo2(μ-OR)2(CO)8]2- has been figured out and the reaction of Mo(CO)6 with alkoxide has also been discussed.