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.     

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.     

Microwave Solvothermal Synthesis,Crystal Structures and in Vitro Antitumor Activities of Di-n-butyltin Piperonylate with a Sn_4O_4 Ladder Framework

A two-dimensional supramolecular compound di-n-butyltin piperonylate, {(μ_3-O)(μ_2-OMe)(n-Bu_2Sn)_2[O_2CAr(C_2H_4O)]}_2 constructed by hydrogen bonds with a Sn_4O_4 ladder-like framework, was obtained by the microwave-assisted solvothermal reaction of di-n-butyltin oxide precursor with the piperonylic acid in methanol environments. The composite was characterized by elemental analysis and IR(~1H, ~(13)C and ~(119)Sn) NMR spectra. The compound crystallizes in monoclinic system, space group P21/n with a = 13.3690(12), b = 14.1442(14), c = 16.4022(16) ?, β = 107.191(6)°, V = 2963.0(5) ?~3, Z = 2, Dc = 1.520 g/cm~3, F(000) = 1368, μ = 1.719 mm~(-1), Mo Kα radiation(λ = 0.71073 ?), the final R = 0.0495 and w R = 0.1260 for 6780 observed reflections with I 2σ(I). Its X-ray crystallography diffraction analyses show a Sn_4O_4 ladder-like skeleton, in which two endocyclic tin and one exo tin atoms are bonded to the μ_3-O atom. In addition, one endocyclic tin and one exo tin atoms are respectively bonded to the μ_2-O atom from methanol. The ladder-like molecule has a three-ring fused skeleton, which is almost coplanar. The endocyclic and exocyclic tin atoms were all five-coordinated with distorted trigonal bipyramidal geometry. The antitumor activity showed that the compound had higher activities than cisplatin in HT-29, HepG2, MCF-7, KB and A549 cell line in vitro.     

THE CRYSTAL STRUCTURE OF THE ADDITION COMPOUND OF DECAVANADIC ACID AND 5,7-DIMETHYL-2, 3-DIHYDRO-1, 4-DIAZEPINIUM

The title compound crystallizes in the space group C_(2h)~5-P2_1/n with unit cell constantsa=10.938 A, b=19.189 A, c=13.384 A and β=105.09°. Intensities of 4022 independent reflec-tions were collected with four-circle diffractometer using MoKa radiation. After reduction fordiffractometer data, we derived first the position parameters of all the V atoms by directmethod using SHELXTL program. The coordinates of all the non-hydrogen and hydrogenatoms were obtained from successive Fourier and difference sytheses. The block-diagonalleast-squares refinement for all atoms gave a final discrepancy weighted factor R_w=0.050. The result of structure analysis shows that four protons of each decavanadic acid arecaptured by the nitrogen atoms involved in the azepine molecules which are condensation pro-ducts of ethylenediamine with acetylaceton. In crystal, the isopoly-decavanadate anion, 7-member heterocyclic azepium and the crystal water are linked together by ionic forces andhydrogen bonding and the chemical content within a unit cell has been identified as 2[H_2V_(10)O_(28)]~(-4)·8[C_7N_2H_(13)]~( 1)·12H_2O.     

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     

MOLYBDENUM-IRON MIXED METAL CLUSTERS (Ⅰ)——THE SYNTHESIS AND STRUCTURAL CHARACTERIZATION OF (η~5-C_5H_5)_2Mo_2Fe_2(μ_4-Te)(μ_3-Te)_2(CO)_6

The reaction of Fe_2(μ_3-Te)_2(CO)_9 with Mo_2(CO)_6(η~5-C_5H_5) affords the title compound. Its X-ray analysis shows a butterfly structure for the Mo_2Fe_2 core; the two molybdenum atoms occupy the hinge with a Mo—Mo bond distance of 2.819 and the two iron atoms are on the tops of the wings with an average Mo—Fe bond distance of 2.932(2). Each molybdenum is bonded to a Cp ring, and three CO ligands are terminally bonded to each iron atom. One tellurium atom quadruply bridges Mo_Fe_2 with Mo—Te(μ_4)=2.625(2). and Fe—Te(μ_4)=2.713(2). Two tellurium atoms triply bridge the two triangular Mo_2Fe faces with Mo—Te(μ_3)=2.678(1) and Fe—Te(μ_3)=2.513(3). The molecule has C_(2v) symmetry and a bicapped triangle bipyramidal skeleton. Crystallographic parameters are as follows: space groupImm2(orthorhombic), a=14.562(3), b=10.391(1), c=7.139(4), V=1080.2(i)~3, Z=2, ρ(cald)=1.819g·cm~(-3). The final R factor was 2.2％ for 620 independent reflections(I>2σ(I)).     

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     

Synthesis,Crystal Structure and Photoluminescence Property of Ag(I) with N,N-dimethyl-4-(pyridine-4-yldiazenyl)aniline

A 2D plane coordination compound [Ag_2(Dpya)_2.(NO_3)_2]n was synthesized and characterized by FT-IR,elemental analysis and TG analysis.The red crystal was obtained via solvent diffusion method at room temperature and is slightly soluble in organic solvents.Its structure was determined by single-crystal X-ray diffraction analysis.It crystallizes in monoclinic,space group P1 with a = 10.7995(13),b = 7.4748(8),c = 18.364(2) ?,β = 98.916(4)o,V = 1464.5(3) ?~3,Z = 2,C_(26)H_(28)Ag_2N_(10)O_6,M_r = 792.32,Dc = 1.302 Mg/m~3,F(000) = 792,μ(Mo Ka) = 1.356 mm~(-1),R = 0.0575 and w R = 0.0826.The compound [Ag_2(Dpya)_2.(NO_3)_2]_n is a two-dimensional structure and there are two kinds of coordination configurations about the Ag atoms in the compound.The Ag(1) center is tetrahedrally coordinated with two O atoms of NO_3~-and two N atoms from the ligand Dpya.Meanwhile,the Ag(2) is five-coordinated by five O atoms from three NO_3~-anions.The Ag centers(Ag(1) and Ag(2)) connect to themselves as well as with each other by the bridging NO_3~-anions.And the coordination compound shows photoluminescence with an emission peak at 530 nm(λex = 450 nm) as the ligand Dpya.     

SUBSTITUTION REACTION OF LIGANDS IN TRINUCLEAR Mo CLUSTERS WITH "LOOSE COORDINATION SITE" AS WELL AS SYN-THESIS AND CRYSTAL STRUCTURE OF Mo_3(μ_3-S) (μ-S)_3(dtp)_3(C_3H_4N_2)_3 (dtp)·(CH_3)_2CO

When trinuclear molybdenum cluster compound with "loose coordination site", Mo_3(μ_3-S)(μ-S)_3(μ-dtp)(dtp)_3·H_2O(A) (dtp=diethyldithiophos-phinato anion), is reacted with an excess of imidazole, the H_2O ligand and the bidentate bridging ligand μ-dtp are found to be simultaneously substituted by the imidazole to form the title compound. The title crystal belongs to the space group P(?), Z =2, with the following unit cell parameters: a=14.465(2), b=14.653(4), c=14.886(6), α=99.36(3),β=93.11(2),γ=114.29(2),V=2812(3). The crystalline compound consists of an ordered array of the cluster cation and dtp anion with acetone as packed molecule. The cation possesses a symmetry of C_3. Three Mo atoms form basically an equilateral triangle with three Mo—Mo bond lengths of 2.763 (1), 2.762(1), 2.756(1) respectively.     

THE SYNTHESIS AND CRYSTAL STRUCTURE OF A NOVEL TETRANUCLEAR COPPER (Ⅰ) CLUSTER COMPLEX, Cu_4(α-C_(10)H_7CSS_2)_4·1/2CS_2

The title compound has been synthesized by the reaction of sodium α-dithionaphthoatewith CuCl_2 in an alkaline aqueous solution or by the reaction of α-dithionaphthoic acid withCuCl_2 in an organic solvent, The crude product was recrystallized in a mixture of CS_2 andC_2H_5OH. The crystals obtained are red and stable in air. The structure of the title compound is determined by a single-crystal X-ray diffractionanalysis. The crystal belongs to monoclinic space group C_(2h)~5- P(2_1/a) with unit cell parameters:a= 16.453(3)A, b=12.651(4)A, c=23.182(7)A, β=100.5(2)°, V=4744.6A~3,Z=4. Thestructure was refined to R=0.06 for 4707 reflections. In the molecule, Cu_4 cluster has a distorted tetrahedral configuration. Surrounding thistetrahydron are four α-perthionaphthoate ligands, coordinated to copper through the sulfuratoms. One of the sulfur atoms in each ligand forms sulfur bridge with copper atoms,while the other is coordinated to only one copper. The three Cu--S bonds formed by thethree sulfur atoms with a given copper atom are approximately coplanar. Each group--C--S_2 with Cu atom on a vertex of the tetetrahedron forms a five-member ring. Thesefive-member rings are also approximately cooplanar. The molecule possesses an approachingS_4 point symmetry. The mechanism for the formation of the title compound involves a redox reaction.which is discussed in this paper.     

THE CRYSTAL STRUCTURE OF TR1S (μ-SULFJDO)-(U3-SULFJDO)-TETRAKTS (O,O-DIETHYLPHOSPHORODITHIOATO-S,S)-OXAZOLE-TRI-MOLYBDENUM-ANTIMONOUSCHLORID {Mo_3(U3-S)[u-S)_3·SbCl_3][S_2P(OEt)_2]_4·(C_3H_3ON)}

<正> Mr = 1445.67, triclinic. The space group is P1 with the unit cell parameters: a = 10.342(3), b = 11.994(3), c = 21.352(4) A; (?)= 76.27(2), β - 88.55(2)°, r = 73.26(2)°; V = 246lA3, Z = 2, DC = 1.959 g.cm-3. The final R factor is 0.068 based on 4053 reflectioons with I≥3(?)(Ⅰ). The title compound may be regarded as the result of that a molecule of trinuclear Mo cluster {Mo3S4[S2P(OEt)2]4·(C3H3ON)}[1] connects with a molecule of SbCl3 by three bridging S atoms. The skeleton {Mo3SbS4} is a distorted cube. The distances of Mo-Mo bonds are 2.728(2), 2,743(2) and 2.751(2) A, respectively, and the distances between Sb and Mo atoms are 3.814(2), 3.815(2) and 3.847(2) A, respectively.     

SYNTHESIS AND CRYSTAL STRUCTURE OF [(η~5-C_5H_5)_2NdCl·OC_4H_8]_2

All attempts to prepare light lanthanide dicyclopeutadienyt chloride failed,due to the disproportionation reaction. The crystal complex of [(η~5-C_5H_5)_2NdCl.OC_4H_8]_2 was successfully prepared by the reaction of NdCl_3·2C_4H_8O with cyclopentadienyl sodium (molar ratio 1:1.8)in tetrahydrofuran at room temperatureThe composition of the title compound was determined by the methods of elemental analysis, infrared spectroscopy and photoelectron spectroscopy. The crystal structure of [(η~5-C_5H_5)_2NdCl·OC_4H_8]_2 was determined from single crystal X-ray diffraction. Data were collected at-60℃ under dry nitrogen atmosphere.The complex crystallizes in the monoclinic space group P2_1/c,with Z=2. Lattice parameters are: a=8.201(3), b=21.589(6),c=8.596(3),β=109.10(3)°.The structure was solved by Patterson and Fourier techniques and refined by least-squares to a final conventional R=0.0636 for 1680 reflections. There are two Nd atoms in the dimeric unit which are bridged asymmetrically by the two chlori     

Synthesis,crystal structure,magnetic properties and second harmonic generation of a new noncentrosymmetric coordination compound:Triaqua(4-amino-6-methoxypyrimidine) cuprate(Ⅱ)sulfate

The chemical preparation, crystal structure and infrared spectroscopic characterization of the triaqua(4-amino-6-methoxypyrimidine) cuprate(II) sulfate, [Cu(C_5H_7N_3)(H_2O)_3]SO_4, is reported. The compound crystallizes in the noncentrosymmetric orthorhombic space group P2_12_12_1 with lattice parameters a = 7.9025(3), b = 11.1189(4), c = 12.9720(4) , V = 1139.81(7) ~3 and Z = 4. The Cu(II) cation is fivecoordinated, in an early half-way between square pyramidal and trigonal bipyramidal fashion, by two nitrogen atoms of the 4-amino-6-methoxypyrimidine ligand and three water oxygen atoms. In the atomic arrangement, the organic ligands and the 5-connected Cu centers are linked with each other to give a 1-D corrugated hybrid chain running along the b-axis direction. The chains are interconnected by the SO_4~(2-) anions via O–H...O, O–H...S, C–H...O and N–H...O hydrogen bonds to form layers spreading parallel to the(011) plane. The vibrational absorption bands were identified by infrared spectroscopy. Quantitative measurements of the second harmonic generation(SHG) of a powdered sample at 1064 nm were performed and a relative efficiency of 5.2 times the KDP standard was observed. Magnetic properties were also defined to characterize the complex. Magnetic measurements revealed that this material had a onedimensional antiferromagnetic character. The magnetic parameters were g = 2.11 and 2J/k B = -36 K.     

Synthesis and Structure Study of Molybdenum Complex Mo[o-NHCOCH_3-m-NO_2C_6H_3COOH]_2_O2Cl_2·PhCl

The crystal and molecular structures of molybdenum complex, Mo [ o- NHCOCH3- m-NO2C6H3COOH]2O2Cl2.PhCl are reported. The crystal belongs to space group Cc of monoclinic system with unit cell parameters:α= 11. 214 (3) A .b= 19. 544 (4 ) A . c = 14. 091 (6) A .β=94.06(3)°,V'=3080.3 A3 and Z=4. The structure was refined to R=0. 061.The coordination number for the Mo atom Is six. The coordination polyhedron formed by four O atoms and two Cl atoms around the Mo atom is a distorted octahedron. Four O atoms and one Mo atom construct a plane. Two benzyl planes in coordinate groups and the benzyl plane of solvent are almost parallel. The quantum-chemical calculations were carried out. There are hydrogen bonds in the Complex. The EHMO calculations and the existence of hydrogen bonds prove that the O atoms are stronger coordinated atoms in the carbonyls than in the carboxyls.     

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.     

THE CRYSTAL STRUCTURE OF BAYLEYITE

The bayleyite crystallizes in monoclinic space group C_2~5h-P2_1/c with a=6.499(1), b=15.235(5), c=26.513(6), β= 92.92(2)°, Z=4. Intensities of 3430 independent reflections are collected with diffractometer using MoKα radiation. The crystal structure has been solved by the Patterson method and refined by block least square refinement for positional parameters and isotropic temperature factor of non-hydrogen atoms. The final R factor is 0.038.The result of crystal structure analysis shows that the structure consists of discrete [UO_2(CO_3)_3]~(4-) ions and Mg~(2 ) cations are between slab-like units, but they are not in a slablike unit. Its crystal struture is different from that of liebigite which was determined by Appleman. Complexes and cations between slab-like units and in a slab-like unit are connected by hydrogen bonds formed by water molecules.     

STUDY ON THE REACTION PERFORMANCE OF CLUSTER COMPOUND——A REACTION OF Cu(+2) CAPTURING LIGANDS FROM MOLYBDENUM CLUSTER AND THE CRYSTAL STRUCTURE OF ITS PRODUCT Cu_8Cl_2[S_2P(OEt)_2]_6

The oxidation-reduction reaction of the molybdenum cluster compound Mo_3(μ_3-S)(μ-S)_2-[μ-SOP(OEt)_2] [S_2P(OEt)_2]_3(O)_2 with CuCl_2·2H_2O has been investigated and the chemical components of its product, Cu_8Cl_2[S_2P(OEt)_2]_6, were confirmed. The crystal belongs to the triclinic system and the space group is P with the following unit cell parameters: a=11.578 (5), b=12.663 (3), c=14.317 (4); α=55.54 (2)°, β=57.35 (3)°, γ=72.23 (3)°; Z=1; D_(calc)=1.926 g·cm~(-3). Final discrepancy factor of R is 0.075 for 3573 unique reflections with I≥3σ(I). The results of investigation show that the crystal structure consists of molecular chains with Cu_8Cl_2[S_2P(OEt)_2]_6 as structural unit, in which eight Cu atoms form a cube-shaped cage. The coordination sphere of each Cu atom is a tetrahedron configuration. The distances between Cu atoms are 3.018-3.437, which indicates that there are no metal-metal bonds between Cu atoms. It is worthwhile to study further the phenomenon how Cu(+2) captures the     

RESEARCH ON TRINUCLEAR MOLYBDENUM CLUSTER COMPOUNDS——CRYSTAL AND MOLECULAR STRUCTURES OF (Et_4N)_2[Mo_3(μ_3-O)(μ_2-Cl)_3(Oac)_2Cl_5]

The title compound forms black crystals shaped like pseudo-octahedrons, which belong to the orthorhombic system The space group is Pna 2_1 with unit cell parametrs of a=17.815(1), b=16.629(2), c=12.003(1), and with Z=4, D_(obs)=1.80g·cm~(-3), and D_(calc)=1.804g·cm~(-3). The crystal structure was solved by the heavy atom method and refiened by fullmatrix least-squares to a final conventional R factor of 0.048 for 2584 unique reflections with I≥σ(Ⅰ). The investigation confirms that the crystal structure consists of tetraethylammonium cations and trinuclear Mo cluster anions. The anion is a μ_3-O monocapped trinuclear cluster with an average Mo-Mo bond length of 2.60 (2). On the side of the Mo_3 triangular plane opposite to the μ_3-O atom, each two Mo atoms are bridged by a Cl atom with the result that these seven atoms (3 Me, 1 O and 3 Cl atoms)form an apex-deficient quasicubane configuration. In addition, each Mo atom is coordinated to three additional atoms resulting in a pseudo-octahedral geome     

SYNTHESIS,STRUCTURE,PROPERTIES AND QUANTUM-CHEMICAL STUDIES OF CUBANE-LIKE CLUSTER COMPOUND WITH ALL-CHELATING LIGANDS [(C_2H_5)_4N]_2{Fe_4S_4[S_2CN(C_2H_5)_2]_4}

Under anaerobic and water-free condition and pure dinitrogen atmosphere, the title com-pound has been synthesized from FeCl_2, (NH_4)_2WS_4, NaS_2CN(C_2H_5)_2 and (C_2H_5)_4NBr. Thecompound crystallizes in the monoclinic space group Cc with cell constants a = 22. 125(6)A,b = 11.313(3) A, c = 25.053(8) A, β= 118.05(2)°, V = 5534.2A~3, Z = 4. It contains cubane-like Fe_4S_4 core. Each Fe atom in the compound is coordinated by a disulfide-chelate ligand.The determination results of the Mossbauer spectrum arid XPS, and quantum-chemical cal-culation all show that the compound contains two kinds of Fe in different valence states butin an equal amount. The scheme of the formation reaction for the compound is given. Thespectra of IR and UV-vis, and redox properties for the compound are reported.     

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.