Cp*MCpMoFe(CO)7(μ3-S), Cp*MoCpMFe(CO)7(μ3-S) (M = W,Mo) and Cp*WCp*MoFe(CO)7(μ3-S). Crystal structure of CpMoCp*WFe(CO)7(μ3-S)

CpMoFeCo(CO)₇(₃-S) reacts with Cp^*M(CO)₃Cl or CpM(CO)₃Cl (M=W, Mo) to gave the mixed-metal clusters Cp^*WCpMoFe(CO)₇(₃-S) (1), Cp^*MoCpMoFe(CO)₇(₃-S) (2), CpWCp^*MoFe(CO)₇(₃-S) (3), CpMoCp^*MoFe(CO)₇(₃-S) (4) and Cp^*WCp^*MoFe(CO)₇(₃-S) (5). The title clusters have been characterized by i.r., ¹H/¹³C-n.m.r. spectroscopy and their compositions have been confirmed by elemental analyses. The X-ray crystal structure analysis shows the two independent enantiomeric molecules of clusters (1) in one crystal structure unit.     

Syntheses and Single-crystal Structures of Ln_3Sn_(0.25)GeS_7 (Ln=La,Sm)

Two new quaternary sulfides,La3Sn0.25GeS71 and Sm3 Sn0.25GeS72,have been synthesized by a facile solid-state reaction,and their crystal structures were determined by singlecrystal X-ray diffraction analysis.The two compounds crystallize in the P6 3 space group,and the crystal data are as follows-La3Sn0.25GeS7:a=10.3335(7),c=5.8455(7),Z=2;Sm3Sn0.25GeS7:a=9.999(3),c=5.787(2),Z=2.Single-crystal analysis indicated that the two compounds consist of three types of building blocks:LnS 8 anti-tetragonal prism,SnS 6 octahedron,and GeS 4 tetrahedron.     

Synthesis and Biological Properties of 3-(Dihydroxybenzoyloxy)methyl- and 3-(Diacetoxybenzoyloxy)methyl-7α-chlorocephalosporanate Sulfones

We describe the synthesis of tert-butyl esters of 3-(2-hydroxybenzoyloxy)methyl-, 3-(dihydroxybenzoyloxy)methyl-, and 3-(diacetoxybenzoyloxy)methyl-7-chlorocephalosporanic acid sulfones by reaction of tert-butyl ester of 3-bromomethyl-7-chlorocephalosporanic acid sulfone with salts of hydroxy- and acetoxy-substituted benzoic acids. We have investigated the elastase-inhibiting properties of the compounds obtained and also their in vitro cytotoxic activity.     

Synthesis and Crystal Structure of Tetraamminelithium-Rubidiumtriselenide, Li(NH3)4RbSe3, and Pentaamminesodium-Rubidiumtriselenide-Ammonia(1/3), Na(NH3)5RbSe3 · 3NH3

Summary. The ammoniates Li(NH₃)₄RbSe₃ and Na(NH₃)₅RbSe₃·3NH₃ were prepared by the reduction of Rb₂Se₅ with lithium or sodium in liquid ammonia. Single crystals were isolated and characterized by X-ray structure analysis using low temperature techniques. Both compounds contain triselenide anions Se₃^2–, which coordinate to rubidium cations forming ¹[RbSe₃]^– or ¹[Rb(NH₃)₂Se₃]^– chains. The chains are separated in the crystal structures by the homoleptic ammine complexes Li(NH₃)₄⁺ and Na(NH₃)₅⁺.     

Synthesis,crystal structures and photoluminescence of 7-(N,N′-diethylamino)-3-phenylcoumarin derivatives

Two new coumarin derivatives, 7-(N,N′-diethylamino)-3-(4-hydroxyphenyl)-coumarin and 7-(N,N′-diethylamino)-3-(4-bromophenyl)-coumarin, were synthesized successfully. Their structures were verified by single crystal X-ray crystallography. The UV–vis absorption and fluorescence of the compounds were discussed. The compounds exhibit strong blue emission under ultraviolet light excitation. The molecular structures, the lowest energy transitions and the UV–vis spectra of 7-(N,N′-diethylamino)-3-(4-hydroxyphenyl)-coumarin and 7-(N,N′-diethylamino)-3-(4-bromophenyl)-coumarin have been studied with density functional theory (DFT) and time-dependent density functional theory (TD-DFT) at B3LYP/6-31G(d) level.     

Synthesis,crystal structure,and catalytic performance of two 3-D supramolecular compounds: (C7N2H7)3(C7N2H6) · PMo12O40 · 2H2O and (C7N2H7)3(C7N2H6)2 · AsMo12O40 · 3H2O

Two organic–inorganic compounds based on Keggin building blocks have been synthesized by hydrothermal methods, (C₇N₂H₇)₃(C₇N₂H₆)?·?PMo₁₂O_40?·?2H₂O (1) and (C₇N₂H₇)₃(C₇N₂H₆)_2?·?AsMo₁₂O_40?·?3H₂O (2) (C₇N₂H₆?=?benzimidazole). Single-crystal X-ray analysis revealed that 1 crystallized in the triclinic system, P-1 space group with a?=?9.8980(4)?Å, b?=?11.2893(4)?Å, c?=?25.8933(9)?Å, α?=?93.307(2)°, β?=?90.630(2)°, γ?=?108.330(2)°, V?=?2740.68(18)?ų, Z?=?2, R ₁(F)?=?0.0740, ωR ₂(F ²)?=?0.1511, and S?=?1.037; 2 crystallized in the triclinic system, P-1 space group with a?=?12.3353(4)?Å, b?=?13.2649(4)?Å, c?=?20.2878(6)?Å, α?=?95.6630(10)°, β?=?100.1720(10)°, γ?=?99.3940(10)°, V?=?3195.72(17)?ų, Z?=?2, R ₁(F)?= 0.0329, ωR₂ (F ²)?=?0.1236, and S?=?1.088. The two compounds show a layer framework constructed from Keggin-polyoxoanion clusters and benzimidazole via hydrogen bonds and π–π stacking interactions, resulting in a 3-D supramolecular network. Both have high catalytic activity for oxidation of methanol. When the initial concentration of the methanol is 5.37?g?m^?3 in air and the flow velocity is 4.51?mL?min^?1, methanol is completely eliminated at 150°C for 1 (160°C for 2).     

Properties and structure of new volatile phenyl-containing β-diketonates of trimethylplatinum(IV): (CH3)3Pt(btfa)H2O, (CH3)3Pt(bac)Py, and initial complex [(CH3)3PtI]4

By interaction of trimethylplatinum(IV) iodide with phenyl-containing β-diketonates, the volatile monomeric complexes of trimethylplatinum(IV) based on benzoyltrifluoroacetone (Hbtfa) and benzoylacetone (Hbac) of the composition (CH₃)₃Pt(btfa)H₂O (I) and (CH₃)₃Pt(bac)Py (II) are obtained. Synthesis of the complexes is described; data of elemental analysis and IR spectra are reported; thermal characteristics are studied by thermogravimetry. For the first time, a single crystal X-ray diffraction study of complexes (I), (II), and the initial tetrameric complex [(CH₃)₃PtI]₄ (III) is performed.     

The all non-metal homodinuclear and heterodinuclear sandwich-like compounds C2(η3-L3)2 and BN(η3-L3)2 (L = BCO, BNN and CBO)

Density functional theory studies on the all non-metal homodinuclear and heterodinuclear sandwich-like compounds C(2)(η(3)-L(3))(2) and BN(η(3)-L(3))(2) (L = BCO, BNN and CBO) have been performed. The staggered conformations of both C(2)(η(3)-L(3))(2) and BN(η(3)-L(3))(2) are predicted to be stable. The non-metal direct C-C and B-N bonds are covalent with σ interactions, which are formed by the interactions of s and p(z) orbitals of the center atoms. Different from the ionic metal-ligand bond in the traditional metal center sandwich-like compounds, the C-L, B-L, and N-L bonds are covalent in these all non-metal sandwich-like compounds. The NICS values indicate that the ligands of C(2)(η(3)-L(3))(2) and BN(η(3)-L(3))(2), as well as their bare rings, display multiple aromaticity (σ and π aromaticity). Both σ and π aromaticity of the ring ligands towards the center atoms become stronger after complexation with the center atoms, while the π aromaticity against the center atoms is reduced. The π aromaticity of the ligands bonded to different center atoms follows a trend of B > C > N, and the (CBO)(3)(+) ligands bonded to B possess the strongest π aromaticity. The dissociation reactions and possible synthetic reactions analysis show that these all non-metal sandwich-like compounds are stable, and the homodinuclear species are more stable than the heterodinuclear ones. These all non-metal binuclear sandwich-like compounds can be regarded as potential synthetic targets according to the highly negative free energies of the possible synthetic reactions. The isomerization reactions demonstrate that the CBO-based compounds should be more possible to synthesize in experiments than their BCO-based isomers.     

3-ethyl-3-phenylazetidinone-2—I. Synthesis of (R)-, (S)- and (RS)-monomer,polymerization and properties of polymers

Synthesis and optical resolution of 3-ethyl-3-phenylazetidinone-2 were improved to obtain (RS)-, (R)- and (S)-monomers having optical purities up to 98%, which could successfully be determined by ¹H-NMR 250 MHz using tris[3-(2,2,2-trifluoro-l-hydroxymethylidene)d-camphorato]europium III as a shift reagent. These monomers were polymerized anionically in HMPT using potassium salt as a catalyst and by the addition of 1-acetyl-4,4-dimethylazetidinone-2 as a chain initiator. Optical purity of the starting monomer seemed to be maintained in the resulting polymers, the thermal properties of which were found to depend on the mean length of the stereoblocks contained in the chain. While the reactivity, in particular the case of polymerization, of monomer increased with the optical purity, no evidence could be obtained for stereoregulation by a preferential incorporation of a monomer enantiomer according to the configuration of the growing chain end unit.     

Stable Structure and Characteristic Spectroscopy of(CH3COCH3)n(n=1～7)Clusters

The stable acetone molecule clusters have been studied by using Beeke's threeparameter(B3LYP)density functional theory(DFT)with standard 6-31G(d)basis set.The calculated results show that the optimal structures of acetone clustets are cyclic and the cycles become larger and larger with the increase of cluster size.The strongest vibration peaks for neutral clusters are C=O stretching vibration.The C=O stretching peaks of cyclic acetone clusters split into double ones when n≥3,the frequencies are red-shifted and corresponding intensities increase with the increase of cluster size.     

γ-Fe(2)O(3) and Fe(3)O(4) magnetic hierarchically nanostructured hollow microspheres: Preparation, formation mechanism, magnetic property, and application in water treatment

In this paper, we report the preparation of γ-Fe(2)O(3) and Fe(3)O(4) magnetic hierarchically nanostructured hollow microspheres by a solvothermal combined with precursor thermal conversion method. These γ-Fe(2)O(3) and Fe(3)O(4) magnetic hierarchically nanostructured hollow microspheres were constructed by three-dimensional self-assembly of nanosheets, forming porous nanostructures. The effects of experimental parameters including molar ratio of reactants and reaction temperature on the precursors were studied. The time-dependent experiments indicated that the Ostwald ripening was responsible for the formation of the hierarchically nanostructured hollow microspheres of the precursors. γ-Fe(2)O(3) and Fe(3)O(4) magnetic hierarchically nanostructured hollow microspheres were obtained by the thermal transformation of the precursor hollow microspheres. Both γ-Fe(2)O(3) and Fe(3)O(4) hierarchically nanostructured hollow microspheres exhibited a superparamagnetic property at room temperature and had the saturation magnetization of 44.2 and 55.4emu/g, respectively, in the applied magnetic field of 20 KOe. Several kinds of organic pollutants including salicylic acid (SA), methylene blue (MB), and basic fuchsin (BF) were chosen as the model water pollutants to evaluate the removal abilities of γ-Fe(2)O(3) and Fe(3)O(4) magnetic hierarchically nanostructured hollow microspheres. It was found that γ-Fe(2)O(3) hierarchically nanostructured hollow microspheres showed a better adsorption ability over SA than MB and BF. However, Fe(3)O(4) hierarchically nanostructured hollow microspheres had the best performance for adsorbing MB.     

Vibrational spectra,force constants and mean amplitudes of trimethylsilylacetylene (CH3)3SiCCH and (CD3)3SiCCD

The infrared and Raman spectra of (CD₃)₃SiCCD have been obtained. Normal coordinate analysis of trimethylsilylacetylene and its complete     

Synthesis and molecular and crystal structure of the octanuclear palladium cluster Pd8(μ3-CO)2(μ2-CO)6(PMe3)7

Treatment of bis(dibenzylideneacetone)palladium with trimethylphosphine under a carbon monoxide atmosphere gives the title complex in good yield. X-ray crystallography has shown the structure of the complex to consist of an octahedron of palladium atoms which is bicapped by two further palladium atoms in an asymmetric fashion. Seven of the eight palladium centres carry terminal trimethylphosphine ligands. Two face-bridging and six edge-bridging CO molecules complete the ligand shell.     

Synthesis, structure, luminescence properties, quantum chemistry and cytotoxic effects of two vanadium(IV) complexes with polypyrazolylborates, HB(pz)3VO(acac) and HB(3,5-Me2pz)3VO(acac)·CH3CN (pz = pyrazole)

The reaction of VO(acac)₂ (acac = acetylacetonate) with NaHB(pz)₃ (pz = pyrazole) or NaHB(3,5-Me₂pz)₃ in methanol gave vanadium(IV) complexes HB(pz)₃VO(acac) (1) or HB(3,5-Me₂pz)₃VO(acac)·CH₃CN (2), respectively. The complexes 1 and 2 were characterized by elemental analysis, IR, UV-vis, NMR and X-ray diffraction crystallography methods. Complex 1 crystallizes in space group P2₁/c, a = 7.641(2) Å, b = 17.008(4) Å, c = 13.362(2) Å; β = 92.092(17)°, V = 1735.5(7) ų, Z = 4. Complex 2 crystallizes in space group P2₁/c, a = 17.410(13) Å, b = 8.076(16) Å, c = 19.300(13) Å; β = 101.75(5)°, V = 2657(6) ų, Z = 4. X-ray structure analyses have shown that the complexes 1 and 2 are monomeric with a similar coordination environment of the vanadium atom. Luminescence properties and cytotoxic effects of the complexes are discussed. On CBRH-7919 cells, the complexes 1 and 2 caused a slight stimulation of growth at low doses (1–10 μM) and a significant cytotoxic effect at higher doses (100–1000 μM). The electronic structure and the bonding characters of the two complexes were analyzed with ab initio calculations. Original Russian Text Copyright ? 2006 by Y. H. Xing, Z. Sun, W. Zou, J. Song, K. Aoki, and M. F. Ge __________ Translated from Zhurnal Strukturnoi Khimii, Vol. 47, No. 5, pp. 924–932, September–October, 2006.     

Near-saturation (P,ρ,T) and vapor-pressure measurements of NH3, and liquid-phase isothermal (P,ρ,T) and bubble-point-pressure measurements of NH3+H2O mixtures

Near-saturation pressure, density, and temperature (P,ρ,T) and vapor-pressure measurements for NH₃ are reported over a temperature range from 279 to 392 K. Liquid-phase isothermal (P,ρ,T) and bubble-point-pressure measurements for two standard mixtures of NH₃+H₂O (x_NH3=0.8360 and 0.9057 mole fraction) are reported over a temperature range from 280 to 379 K and at pressures to 7.7 MPa. These data are compared to literature data and correlations and agree within ±3% for bubble-point pressures, ±0.005 g/cm³ for liquid densities, and ±0.0011 g/cm³ for vapor densities. A consistent data set for equation-of-state optimization at high concentrations of NH₃ is proposed.     

Synthesis and Structure of Acetonitrile Solvates of Copper(II) Monofluoroacetate and Silver(I) Trifluoroacetate, [Cu2(CH2FCOO)4· 2CH3CN](CH3CN) and Ag3(CF3COO)3(CH3CN)2

Compounds [Cu₂(CH₂FCOO)₄· 2CH₃CN](CH₃CN) (I) and Ag₃(CF₃COO)₃(CH₃CN)₂(II) were synthesized and studied by X-ray structural analysis. Crystals Iare monoclinic, space group C2/c, a= 27.854(6), b= 8.286(2), c= 19.428(4) Å, = 106.82(3)°, V= 4292(2) ų, Z= 8, R ₁= 0.0426; crystals IIare triclinic, space group , a= 8.676(2), b= 9.819(2), c= 11.961(2) Å, = 95.27(3), = 109.59(3)°, = 104.60(3)°, V= 911.4(3) ų, Z= 2, R ₁= 0.0252. Structure Iis composed of the structural units (lanterns) typical of copper(II) carboxylates. The presence of an additional acetonitrile molecule noncoordinated by the copper atoms makes it possible to consider compound Ias a lattice clathrate. Structure IIhas no analogs among the silver carboxylates. It simultaneously contains silver atoms with coordination numbers varying from 2 to 4.     

Syntheses and Magnetism of μ-1, 3, 5-Benzenetricarboxylato Trinuclear Manganese(Ⅱ) and Nickel(Ⅱ)Complexes

IntroductionThestudyofmagneticexchangeinteractionbetweenparamagneticcenterspropagatedbymulti-atombridgesisofcurrentinterestduetounderstandingthepathwayofelectrontransferinbio1ogicalsystemandobtainingsomeusefulin-formationaboutdesigningmolecule-basedmagnets.Manypapers['-'Jdealingwithphthalato,isophthalatoandterephthalatoligandsasamulti-atombridgeshavebeenpublished.1thasbeenrevealedbythevariable-temperaturemagneticsusceptibilityinvestigationthatlong-rangemagneticcouplingoccursbetweentwoparamagne…     

Synthesis and cytotoxicity of dinuclear platinum(Ⅱ) complexes of (1S, 3S)-1, 2, 3, 4-tetrahydroisoquinolines

A series of novel dinuclear platinum(Ⅱ) complexes with (1S, 3S)-1,2,3,4-tetrahydroisoquinolines as the ligands were synthesized as potential anticancer agents in several steps starting from commercially available L-DOPA. The cytotoxicities of the series of dinuclear platinum(Ⅱ) complexes of tetrahydroisoquinoline were tested against HCT-8, BEL-7402, A2780, MCF-7, Hela, A549 and BGC-823 cell lines by the MTT test. These complexes showed selective inhibition activity against cisplatin-insensitive cell line Skov3.