SYNTHESIS AND CRYSTAL STRUCTURE OF TWO TRINUCLEAR MOLYBDENUM CLUSTERS CONTAINING A LOOSE COORDINATION SITE, {Mo_3(μ_3—S)(μ—S)_3[S_2P(OEt)_2]_4-(C_3H_3ON)}·CH_3CN (Ⅰ) AND {Mo_3-(μ_3—O)(μ—S)_3[S_2P(OEt)_2]_4-(C_3H_3ON)}(Ⅱ)

The synthesis and crystal structure of two trinuclear molybdenum clusters containing a loosecoordination site, {Mo_3(μ_3-S)(μ-S)_3[S_2P(OEt)_2]_4(C_3H_3ON)}· CH_3CN (Ⅰ) and {Mo_3(μ_3- O)-(μ- S)_3[S_2P(OEt)_2]_4(C_3H_3ON)} (Ⅱ), are reported. Cluster (Ⅰ) belongs to the monoclinic spacegroup p2_1/n, a = 16.579 (3), b = 16.959 (2), c = 16.867 (2) A, β= 94.44 (1)°, V = 4728A~3,Z = 4, D_c = 1.778g·cm~(-3). The crystal structure was solved by the Patterson method with afina1 R value of 0.045. Cluster (Ⅱ) belongs to the triclinic space group Pi, a = 13.175 (4),b = 13.372(6), c = 16.656(3)A, α= 117.87(4), β= 60.09(3), γ= 109.03(3)°, ν= 2231A~3,Z = 2, D_3 = 1.798g·cm~(-3). Direct methods were used to solve the crystal structure with afinal R value of 0.066. Both clusters are monocapped trinuclear ones having an oxazoleoccupied coordination site as their main structural characteristic. The difference in cappingatoms results in the difference in their skeletons, Mo_S_4 in cluster (Ⅰ) vs. Mo_3OS_3     

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 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 AND STRUCTURE OF TWO-ELECTRON HETEROPOLY BLUE K_2H_4SiMo(Ⅴ)_2Mo(Ⅵ)_(10)O_(40)·12H_2O WITH α-KEGGIN STRUCTURE

The single crystal of two-electron heteropoly blue with Si as the heteroatom and α-Keggin structure K_2H_4SiMo(Ⅴ)_2Mo(Ⅵ)_(10)O_(40)·12H_2O was obtained by electrolytic reduction. It crystallizes in a triclinic system with space group P , Mr=2117.73, a= 13.702(4), b=14.107(3), c=14.184(2) ; α=119.27(1), β=93.14(2), ;γ=110. 3(2)°, V=2154.29~3, Z=2, F(000)=1999, μ=36.39cm~(-1), Dc=3.26 g/cm~3. Final R factor is 0.0515. Mo(Ⅴ) is situated in two different edge-shared Mo_3O_(13) groups. The heteropoly blue was characterized by IR, UV, polarography, X-ray photoelectron spectra and ESR. All the results show that the structure of the heteropoly anion with Keggin structure remains unchanged basically in the process of reduction.     

DETERMINATION AND REFINEMENT OF THE CRYSTAL STRUCTURE OF CHAIDAMUITE

Chaidamuite (ZnFe(SO_4)_2(OH). 4H_2O), which is a new sulphate mineral, belongs to the triclinic system, space group P1, with the cell parameters corrected by the least-squares method: a=7.309(2), b=7.202(2), c=9.691(3), α=89.64(3), β=105.89(3), γ=91.11(2)°, Z=2. The crystal structure has been determined by the Patterson method and Fourier syntheses and refined by the full-matrix least-squares method to an R factor of 0.032, using 2833 independent reflections. In the structure, a zigzag chain consists of [Fe(1)O_5(OH)] and [Fe(2)O_5(OH)] octahedra sharing the OH corners, and an octahedral-tetrahedral chain running parallel to the b axis consists of the zigzag chain of Fe octahedra and (SO_4) tetrahedra sharing four pairs of octahedral corners on either side of the zigzag chains. These chains are cross-linked by the isolated [Zn(1)O_2(H_2O)_4] and [Zn(2)O_2(H_2O)_4] octahedra into corrugated sheets parallel to the (100) plane. Adjacent sheets are hydrogenbonded through water molecules.     

Synthesis,Crystal Structure and Photoluminescence Property of Potassium Terbium Polyphosphate KTb(PO_3)_4

The potassium terbium polyphosphate crystal KTb(PO_3)_4 has been synthesized using a high temperature solution reaction method. The structure and composition were characterized by single-crystal X-ray diffraction, powder X-ray diffraction and elemental analysis. The compound crystallizes in the monoclinic space group P21/n with a=10.3182(6), b=8.9129(5), c=10.7940(6) ?, β=105.993(1)o, V=954.3 ?~3, Z=4, Mr=513.91, Dc=3.577 g/cm~3, μ=8.585 mm~(-1), F(000)=960, S=0.955,(Δρ)max=1.380,(Δρ)min=–3.428 e/?~3, the final R=0.0301 and w R=0.0400 for 2301 observed reflections with I 2σ(I). In addition, pure powder of isostructural Rb Tb(PO_3)_4 was synthesized in order to investigate the optical property. Photoluminescence measurements show that both crystals ATb(PO_3)_4(A=K(1), Rb(2)) are promising candidates to become solid-state visible green light-emitting sources.     

CRYSTAL STRUCTURE OF DI - NITRATOBIS(ETHYLCAPROLACTAM)URANYL(Ⅱ) UO_2[CH_2(CH_2)_4CONC_2H_5]_2(NO_3)_2

The crystal structure of Di-nitratobis(ethylcaprolactam)uranyl(Ⅱ) UO_2[CH_2(CH_2)_4CONC_2H_5]_2(NO_3)_2 was established by a single-crystal X-ray diffraction study.It is triclinie, space group P1, with a=7.171(2), b=8.655(3), c=10.182(5)A, α=78.27(3), β=70.63(3), γ=81.76(3)°, V=581.7(4)A~3, Z=l, Dc=1.94 g.cm~(-3).Final R value is 0.0218.The result reveals that uranyl ion is coordinated to six oxygen atoms, two of them are from two carbonyl groups of ethylcaprolactam and the other four are from two nitrate groups.     

Extraction and Absolute Crystal Structure of Stachyose

The title compound stachyose(C24H42O21),a biologicaly active tetrasaccharide,was characterized by X-ray diffraction analysis.It crystallizes in the orthorhombic system,space group P21212 with C24H42O21,a = 23.8760(3),b = 12.71028(12),c = 10.81279(11) ,V = 3281.36(6) 3,Z = 4,Dc = 1.511 g/cm3,Mr = 746.58,F(000) = 1576,and μ = 1.230 mm-1.The final R = 0.0666 and wR = 0.1797 for 6298 observed reflections(I 2σ(I)).The molecular crystal structure of stachyose shows absolute stereochemistry of β-D-fructofuranosyl α-D-galactopyranosyl-(1→6)-α-D-galactopyranosyl-(1→6)-α-D-glucopyranoside.The molecule is composed of two α-D-galactoses,one α-D-glucose,and one β-D-fructose and sequentially linked as α-Gal(1→6) α-Gal(1→6) α-Glc(1→2) β-Fru.The title compound is stacked into a 3D layer structure through hydrogen bonds.NMR spectra data are also assigned.In the crystal packing,X-ray analysis indicates that there are two intramolecular and eleven intermolecular hydrogen bonds in this compound.     

THE CRYSTAL STRUCTURE OF N-(TBUTOXYCARBONYL)-L-METHIONYL GLYCINE ETHYL ESTER

The crystal structure of N-(t-butoxycarbonyl)-L-methionyl-glycine ethyl ester has been determined. The crystal data are: P2_1, α=14.504(6), b=5.015(2), c=12.762(6), β=93.63(3)°, Z=2. The final R is 0.066 for 1495 reflections. The torsion angles of methionyl side chain are X~1=-177.7°. X~2=178.6°, X~3=-71.7°. The plan of the side chain is approximately vertical to the plan of the peptide. The peptide main chains are packed in a parallel β-sheet structure, the main chain torsion angles(φ,ψ) of the methionyl residue being (-118.9°,115.4°). This compound, BOC-L-Met-Gly-OEt, is very similar to certain derivatives used in the peptide transport studies which were carried out by Naider et al.     

CRYSTAL AND MOLECULAR STRUCTURE OF N, N-PLATINUM-DIETHYL-DICHLORIDEDI-L-ASPARTATE

This paper reports the crystal and molecular structure of title compound. 3978 three-dimensional independent reflections were collected by Syntex R3 four circle diffractometer. The crystal is monoclinic with space group P2_1, a=8.074(1), b=11.309(4), c=27.793(9), β=106.84°(2), Z=4. The molecular formula is Pt(C_8 H_(15)O_4N)_a Cl_2. The crystal structure was solved by Patterson method and refined by block matrix least squares refinement techniques. The final R factor is 0.039.The result of crystal structure analysis shows that Pt(Ⅱ) has a dsp~2 hybrid orbital and square coordination. Two C1 atoms are located oppositely to two diethyi-dichloride-di-L-aspartare. N atoms have sp~3 tetrahedral hybrid configurations and form the coordinate bonds with Pt(Ⅱ) atom using their lone pair electrons. By reason of molecular packing and due to the formation of inner hydrogen bonds in the complex molecule, the configuration of L-aspartic acid in the title complex is more twisted than that of L-and DL-aspartic acid     

STUDIES ON DERIVATIVES OF 2, 3-DIHYDRO-4 H-1, 3, 2-BENZOXAZAPHOSPHORINE——THE DETERMINATION OF THE CRYSTAL AND MOLECULAR STRUCTURE OF 2, 3-DISUBSTITUTED-2, 3-DIHYDRO-4H-1, 3, 2-BENZOXAZAPHOSPHORIN-4-ONE (THION)-2-SULFIDE(OXIDE)

The two crystal structures of C_(17)H_(17),N_2O_2Cl_2PS (NP-8) and C_(17)H_(19)N_2O_2PS (NP-10-Ⅱ) have beendetermined by Patterson method. The crystals belong to monoclinic system with space group of P2_1/aand P2_1/n respectively. There are four molecules in the unit cell. Cell parameters: a = 26.622 (7)A, b = 7.711 (2) A., c = 9.461 (3) A, β = 94.90°(4) and a = 18.879(3) A, b = 10.199 (13) A, c = 8.948(3) A, β= 94.30°(3) for the two cells. After refinement by block diagonal matrix least squares me-thod, R factors are 0.046 for 2971 reflections of NP-8 and 0.076 for 1711 reflections of NP-10-Ⅱ. Referring to molecular structures of NP-8 and NP-10-Ⅱ spectra data have been satisfactorilycxplained. The characteristic features of the structures have been discussed.     

Synthesis, Crystal Structure and Properties of a Dinuclear Cobalt（II） Complex [Co2（a-furacrylato）4（Phen）2（H2O）]·C2H5OH

A dinuclear cobalt(Ⅱ) complex [Co2(α-furacrylato)4(Phen)2(H2O)]·C2H5OH has been synthesized with α-furacrylic acid and 1,10-phenanthroline as the ligands, and its crystal structure was determined. The crystal is of monoclinic system, space group C2/c with a=1.07388(8), b=2.4300(2), c=1.86708(14)nm, β=104.3830(10)o, V=4.719.4(7) nm3 , Dc=1.503 g/cm3 , Z=2, F(000)=2196, GOOF=1.053, the final R=0.0343 and wR=0.0883. The crystal structure shows that two neighboring cobalt(Ⅱ) ions are linked by the bridging coordination of two α-furacrylic acid anions and one water molecule, and their end positions are respectively coordinated with two 1,10-phenanthroline molecules and two α-furacrylic acid anions, forming a dinuclear structure. Both cobalt(Ⅱ) ions adopt hexa-coordinated distorted octahedral geometry. The electrochemical and fluorescence properties of the title complex are also discussed.     

THE STUDY OF SPECTRA AND X-RAY CRYSTAL STRUCTURE OF A NOVEL BIONICS INSECTICIDE——(CH_3)_2NHCH(CH_2S_2O_3)_2Na·H_2O

IR and NMR spectra of novel bionics insecticide—C_5NS_4O_6H_(12)Na·H_2O have been studied. The molecular and crystal structures of the compound also have been determined. The compound crystallizes in the monoclinic space group C_(2h)~5, - P2_1/n with α= 8.0972. (9) , b =16.262(4), c = 10.370(3), β= 94.26(2)° and z = 4.The result shows that N atom in this compound captures a proton to form HN~ group, Na~ is in statistical disorder. Therefore, the structural formula of tho compound is (CH_3)_2HN~ —CH(CH_2S_2O_3~-)_2·1/2 (Na~ )_2·H_2O.     

Solvothermal Synthesis,Structure and the Secondorder NLO Properties of a Novel Non-metal 3-D Borophosphate:(NH_4)_2[B_2P_2O_8(OH)_2]

A new non-metal 3-D borophosphate compound formulated as(NH_4)_2[B_2P_2O_8(OH)_2](1) has been synthesized by a solvothermal method and characterized by elemental analysis, energy-dispersive X-ray spectroscopy(EDS), IR spectrum and single-crystal X-ray diffraction. The borophosphate (NH_4)_2[B_2P_2O_8(OH)_2] crystallizes in the cubic system, space group P213 with Z = 2, a = b = c = 7.586(4) ?, V = 436.6(4) ?~3, Mr = 281.64, Dc = 2.127 g/cm~3, λ = 0.71073 ?, μ = 0.551 mm-1, F(000) = 284, R = 0.0277 and w R = 0.0758 for 262 observed reflections with I 2σ(I) and S = 1.082. Its structure is constructed by the connection of PO4 and BO3(OH) tetrahedra to form a 3-D anionic framework containing 4-and 8-membered rings(MRs), with two NH_4~+ cations located in the channels of the 8-membered rings. The N–H···O hydrogen bonds are observed in its packing structure and enhanced the stability of crystal structure. In addition, its thermal stability, UV spectrum and second-order NLO properties have been also investigated.     

SYNTHESIS, STRUCTURE AND ELECTROCHEMICAL STUDIES ON SINGLE MoFe_3S_4 AND WFe_3S_4 CUBANE-TYPE CLUSTER COMPOUNDS*

Single cubane-like clusters, MFe_3S_4(R_2dtc)_5 (M=Mo, R_2=—(CH_2)_4—, Bz_2; M=W, R_2=Me_2, —(CH_2)4—; dtc=dialkyldithiocarbamate) were synthesized by assembly reaction of (NH_4)_2MS_4 (M=Mo, W), FeCl_2 with R_2dtcNa (or NH_4) in DMF. The structure, IR, EPR and cyclic voltammogram are described and discussed. MoFe_3S_4(C_4H_8dtc)_5 was also obtained from the conversion of linear cluster Fe(DMF)_6[(FeCl_2)_2MoS_4] in the presence of C_4H_8dtc NH_4. Both clusters MoFe_3S_4(C_4H_8dtc)_4·2C_2H_5CN and WFe_3S_4(C_4H_8dtc)_5·2DMF crystallize in the monoclinic space group C2/c with a=12.544(2), (Mo-cluster), 12.533(4) (W-cluster); b=20.478(4), 20.121(6); c=19.582(7), 19.659(2);β=102.82(2), 102.96(3)°; and Z=4, 4. Their structures were refined to R=0.057 and 0.064 with use of 2690 and 2179 reflections (ι>3Q(I)), respectively. Many similarities in structure for Mo and W clusters indicate that both Mo and W play a very similar role in the clusters.     

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 and forming mechanism of two novel copper (Ⅱ) α-methacrylate complexes with benzimidazole

Two copper (Ⅱ) a-methacrylate complexes with benzimidazole, Cu [CH_2=C( CH_3)-COO]_2(C_7H_6N_2)_2(1) and Cu_2 [CH_2=C(CH_3)-COO]_4(C_7H_6N_2)_2 (2), have been prepared and characterized by elemental analyses, IR and electronic reflectance spectroscopies. The single crystal X-ray diffraction study of the two complexes shows that complex 1 has a square planar configuration, while complex 2 has a binuclear cage structure. The crystal structural analyses show that both complexes 1 and 2 are monoclinic, with space group P2_1/c, a=0.924 16(8) nm, b=1.233 02(13) nm, c =0.989 1(3) nm, β=91.912(13)°, D_c=1.386 g/cm~3, Z=2, R=0.033 9 for the former; and a=0.905 7(2) nm, b=2.252 1(5) nm, c=1.623 5(4) nm, β=90.11(2)°, D_c =1.411 g/cm~3 , Z=4, R=0.056 8, Cu-Cu=0.266 21 nm for the latter. Different structural types of complexes 1 and 2 were produced simultaneously in the reaction of copper (Ⅱ) α-methacrylate with benzimidazole in methanol solution. The forming mechanism of the complexes has been summarized.     

A NEW TYPE OF CHAIN COMPOUND,STRUCTURE OF TA_4(TE_2)_4TE_4I

Ta_4(Te_2)_4Te_4I,Mr=2381.90,Monoclinic,C2/c,a=21.987(2),b=6.153(2),c=19.936(3),β=122.42(14),V=2276.7 ~3,z=4,Dm=6.8(5)g/cm~3,Dc=6.95g/cm~3,λ(Mok)=0.71073,μ=354.0cm~(-1),F(000)=3876,T=296(1)k,R=5.3%,Rw=6.8%,for 1118 uniqueobserved reflections(1>3σ(Ⅰ)).The structure is composed of [Ta_4(Te_2)_4Te_4I]_∞~chains,which are formed by the four-nuclear butterfly cluster units "Ta_4(Te_2)_4Te_4"with the Ⅰ atoms as the bridging atoms between different cluster units.     

CRYSTAL STRUCTURE OF GOSSYPOL ACETIC ACID

The crystal structure of gessypol acetic acid (C_(30)H_(30)O_8-CH_3COOH) has been determinedby X-ray diffraction method. The crystals are triclinic with space group P1, unit cell dimen-sions: a=14.278(7)A, b=6.924(5)A, c=14.706(6)A, α=91.90(5)°, β=92.34(3)°, γ=98.71(5)°, Z=2. The structure has been solved by direct methods and refined by full-matrixleast-squares to a final conventional R=0.063 for observed reflexions. The crystal structureshows that the gossypol acetic acid is a complex which consists of one gossypol molecule andone acetic acid molecule through hydrogen bonding. However, there are no additional hydro-gen bonds between these complexes. The crystal structure is stabilized by Van der Waalsinteractions only.     

STUDIES ON STRUCTURES OF SOME PLATINUM COMPLEXES WITH 1, 1-CYCLOPROPANEDICAR BOXYLATE

The crystal structure, of [Pt(NH_3)_2CPrDCA]. H_2O (Ⅰ), [Pt(CH_3NH_2)_2CPrDCA] (Ⅱ), and [Pt(dmbn) CPrDCA]·2.5H_2O(Ⅲ) (where CPrDCA is 1, 1-cyclopropanedicarboxylate; dmbn is 2, 3-dimethyl-2, 3-butyldiamine) are determined. Compound Ⅰ crystallizes in the orthorhombic space group P_(nma) with the cell dimensions: a=6.517(2), b=9.709(3), c=14.205(5), Z=4, R=0.058. Compound Ⅱ is monoclinic with space group P2_1/n, a=9.648(3), b=8.720(2), c=12.770(4), β=107.12(2), Z=4, R=0.059. Compound Ⅲ belongs to the monoclinic system space group P2_1/m with the cell dimensions: a=6.494(1), b=19.638(3), c=6.606(1), β=94.44(1), Z=2, R=0.038.Electronic structures of the complexes are studied and the correlstion between structure of the amine ligands and biological activity of the complexes is explored.