Structure of a catalytically active octanuclear cobalt complex [Co(II)4Co(III)4(μ4-O)4(μ-O2CPh)12(PhCOOH)4]

The structure of a catalytically active octanuclear mixed-valence cobalt complex [Co(II)₄Co(III)₄(μ₄-O)₄(μ-O₂CPh)₁₂(PhCOOH)₄] (Ph = phenyl, C₆H₅) has been determined using an X-ray diffraction analysis. The presence of 16 ligands containing phenyl rings in each complex gives rise to strong steric stresses and leads to a disordering of terminal groups. The compound crystallizes in the monoclinic crystal system, space group of symmetry P2₁/n, with the unit cell parameters a = 18.076(5) ?, b = 26.371(3) ?, c = 22.791(5) ? β = 92.48(1)°, V = 10853(4) ?³, Z = 4, and ρ = 1.516 g/cm³. The final values of the discrepancy factors are R1 = 0.0441 for 4005 symmetrically nonequivalent reflections with I ≥ 2σ(I), wR2 = 0.1131, and GooF = 0.943.     

Crystal Structure and Magnetic Properties of a Novel Helical Coordination Polymer [Cu2(pda)2(phen)2(H2O)2]·6H2O

A novel coordination polymer of Cu^II with flexible ligands, namely, [Cu ₂ (pda) ₂ (phen) ₂ (H ₂ O) ₂ ]·6H ₂ O (1) (H₂pda = 1,3-phenylenediacetic acid, phen = 1,10-phenanthroline), was synthesized by hydrothermal reactions and characterized by single-crystal X-ray diffraction, thermogravimetric analyses, elemental analysis and IR spectroscopy. In complex 1, the Cu^II ions are linked by pda ligands to form 1D helical chains. The adjacent chains are related by the π–π stacking interactions and exhibit opposite chirality, which result in extended 2D heterochiral helical-layers. Furthermore, the 2D helical-layers are assembled into 3D supramolecular edifices through heterochiral helical hydrogen bonding. In addition, the thermal stability and magnetic properties of 1 are reported.     

A Ladder-like Coordination Polymer [Sr(H2O)4(CuL)2]·(CuL)·2.25H2O Constructed From Metallo-Ligand Na[CuL] and Sr(NO3)2: Crystal Structure and ESR Study

Ligand L (H₃L = Glycylglycine, N-[1-(2-hydroxy,5-bromophenyl)propylidene]) has been prepared which contain flexible dipeptide group and substituted phenol group. The ligand react with Cu(NO₃)₂ to give the metallo-ligand [CuL]⁻, in which L acting as quadridentate ONNO chelate, coordinate to Cu(II) ion. The metallo-ligand [CuL]⁻ is rigid and has multifunctional groups. Reaction of metallo-ligand with Sr(NO₃)₂ leads to the formation of the title complexes [Sr(H₂O)₄(CuL)₂]· (CuL)·2.25H₂O (1). This heteronuclear compound has been characterized by elemental analyses, spectroscopic analyses, and single crystal diffraction. Structural analyses reveal that the complex was crystallized in triclinic space group P-1 and has intricate 2D net-structure, which contain an infinite 1D [Sr(H₂O)₄(CuL)₂]⁺ ladder-like structure. In addition ESR (electron spin resonance) property and thermogravimetric analysis of 1 are discussed in detail.     

Copolymerizations of ethylene with 1–decene over various ansa–metallocene complexes combined with Al( i-Bu) 3/ [CPh 3] [B(C 6F 5) 4] cocatalyst

Copolymerizations of ethylene with 1-decene were carried out with a series of stereospecific metallocene compounds, rac–(EBI)Zr(NMe₂)₂ [ 1, EBI = ethylene–1,2–bis( 1–indenyl)], rac–(EBI)Hf(NMe₂ (2), rac–Me₂Si( 1–C₅H₂–2–Me–4– ^t Bu)₂Zr(NMe₂)₂ (3), ethylidene(cyclopentadienyl)(9-fluorenyl)ZrMe2 [4, Et(Flu)(Cp)ZrMe2] and isopropylidene(cyclopentadienyl)(9–fluorenyl)ZrMe₂ [5, iPr(Flu)(Cp)ZrMe₂], combined with Al(i–Bu)₃/[CPh₃] [B(C₆F₅)₄] cocatalyst. All catalyst systems showed very high copolymerization rates and the 1–decene reactivity decreased in the order of 2 > 5 > 1 4 > 3. The reactivity product of ethylene and 1–decene (r _E x r _D) was below 1 except 3 catalyst, corresponding to random copolymer structures with an alternating character. The melting point (T_m), crystallinity (X_C), intrinsic viscosity ([] and density of the 1–decene/ethylene copolymers decreased markedly with an increase in the 1–decene content, regardless of the type of catalytic system.     

From Metalloligand to Extended 3D Network: Synthesis, Crystal Structure and Magnetic Property of {[Cu(en)2][Cu(μ3-pydc)2]·6H2O}n

A novel 2D coordination polymer, {[Cu(en)₂][Cu(μ₃-pydc)₂]·6H₂O} _n (1) pyridine-2,3-dicarboxylic acid (pydcH₂); ethylenediamine (en), based on the metalloligand [Cu(μ-pydcH)₂] _n , has been prepared and characterized by IR, UV–Vis and ESR spectroscopy, thermal analysis, differential scanning calorimetry and single crystal X-ray diffraction techniques. The temperature dependent magnetic properties have also been studied. The pydc ligand exhibits tetradentate-μ₃ bridging mode, being coordinated through three carboxylate oxygens and one nitrogen atom. The complex contains two copper(II) ions that exhibit two different coordination environment with two en and two pydc ligands. The single crystal structure shows that the complex forms a 3D framework with 2D layers along the c-axis. Van der Waals interactions are responsible for the self-assembly of the layer into a 3D network.     

Hydrothermal Synthesis and Crystal Structures of Cd(II)-Based 1D Coordination Polymer and Mn(II) Coordination Complex with Mixed N- and O-donor Ligands: [Cd2(4-4′-bpy)2(pa)4]n·0.25(H2O) and [Mn(4-4′-bpy)2(pa)(H2O)3]ClO4·2(H2O)

Two new complexes, [Cd₂(4-4′-bpy)₂(pa)₄] _n ·0.25H₂O (1) (pa = phenylacetate), and [Mn(4-4′-bpy)₂(pa)(H₂O)₃]ClO₄·2H₂O, (2), have been obtained from hydrothermal reaction of Cd(NO₃)₂·4H₂O and Mn(ClO₄)₂·6H₂O with a mixture of the ligands, 2-phenylmalonic acid (2-phmalH₂) and 4-4′-bipyridine (4-4′-bpy). The pa is formed in situ by decarboxylation of phenylmalonic acid. These complexes have been characterized by elemental analysis, FT-IR spectroscopy, thermogravimetric analysis and single-crystal X-Ray diffraction. The Cd(II) center is seven-coordinate and linked via pa ligands to form a binuclear complex in the asymmetric unit of 1. A ladder-like 1D chain of binuclear units is formed by Cd(II)–N coordination bond through 4-4′-bpy ligands. Complex 2 consists of a mononuclear manganese center based on a distorted octahedral geometry and exhibits a supramolecular structure containing hydrogen bonds and extensive π···π and C–H···π interactions.     

[Cd2（PIEA）2（μ-Cl）2Cl2]配合物的合成及晶体结构

以[2-(2-吡啶基)咪唑-1-基]乙酸乙酯为配体合成了配合物[Cd2(PIEA)2(μ-Cl)2Cl2],测定了其X-射线单晶结构。晶体学数据:P–l空间群,a=0.8978(3)nm,b=0.5462(3)nm,c=1.0719(3)nm,α=84.335(3)°,β=71.245(3)°,γ=62.323(3)°,V=0.7622(3)nm3,Z=1,s=1.069,最终残余因子(I>2σ(I)),Rl=0.0249,wR2=0.0712;对于全部数据Rl=0.0271,wR1=0.0726。     

[Cu2（PIMA）2（μ-Cl）2Cl2]配合物的合成及晶体结构

以[2-(2-吡啶基)咪唑-1-基]乙酸甲酯为配体合成了配合物[Cu2(PIMA)2(μ-Cl)2Cl2],测定了其X-射线单晶结构。晶体学数据:P2(1)/n空间群,a=14.536(3),b=6.9474(14),c=14.536(3),α=90.00°,β=109.48°,γ=90.00°,V=1383.9(5)3,Z=2,s=1.049,最终残余因子(I>2σ(I)),Rl=0.0324,wR2=0.0753;对于全部数据Rl=0.0466,wR1=0.0796。     

Crystal structure and enhanced microwave dielectric properties of the Ce2[Zr1−x(Al1/2Ta1/2)x]3(MoO4)9 ceramics at microwave frequency

Dense microwave dielectric ceramics of Ce₂[Zr_1−x(Al_1/2Ta_1/2)_x]₃(MoO₄)₉(CZMAT) (x = 0.02–0.10) were prepared by the conventional solid-state route. The effects of (Al1/2Ta1/2)⁴⁺ on their microstructures, sintering behaviors, and microwave dielectric properties were systematically investigated. On the basis of the X-ray diffraction (XRD) results, all the samples were matched well with Pr₂Zr₃(MoO₄)₉ structures, which belonged to the space group R3¯c. The lattice parameters were obtained using the Rietveld refinement method. The correlations between the chemical bond parameters and microwave dielectric properties were calculated and analyzed by using the Phillips—Van Vechten—Levine (P—V—L) theory. Excellent dielectric properties of Ce₂[Zr_0.94(Al_1/2Ta_1/2)_0.06]₃(MoO₄)₉ with a relative permittivity (ε_r) of 10.46, quality factor (Q × f) of 83,796 GHz, and temperature coefficient of resonant frequency (τ_f) of −11.50 ppm/℃ were achieved at 850 ℃.     

[Ni（IMI）6]（NO3）2的制备与晶体结构

咪唑(IMI)与硝酸镍反应,得到硝酸六咪唑合镍配合物,并培养出单晶。元素分析、红外光谱、X射线单晶衍射等分析表明,该晶体属于单斜晶系,空间群为P21/n,晶胞参数a=1.235 0(3)nm,b=1.235 0(3)nm,c=1.480 0(3)nm,β=90.579(2)°,V=1.955 0(7)nm3,Dc=1.491 g/cm3,Z=4,F(000)=900,R1=0.034 4,wR2=0.095 5。该化合物的分子式为[Ni(IMI)6](NO3)2,是由6个咪唑分子直接与二价镍离子配位,硝酸根离子结合形成的配合物。     

四元混配配合物[Ln(x-MBA)2(NO3)(Phen)]2的合成及表征

在酸性介质,乙醇/水混合溶剂中合成得到了三个系列的四元混配配合物[Ln(x-MBA)2(NO3)(Phen)]2(Ln=La、Ce、Pr、Nd、Sm、Eu、Gd、Tb、Er;MBA=CH3C6H4COO-).用元素分析、IR、UV、DTA-TG和1HNMR等方法对配合物进行了表征,测量了三个Eu配合物的荧光光谱和三个Gd配合物的ESR谱.     

On the local structure of Cd3+ centers in (BaGeO3)1 ? x ? y (Al2O3) x (0.45CaF2 · 0.55MgF2) y glasses

A correlation between the ¹⁵⁵Gd M?ssbauer spectra of the GdAlO₃ and Gd₃Al₅O₁₂ compounds and Gd³⁺-doped glasses in the (BaGeO₃)_{1 − x − y} (Al₂O₃) _x (0.45CaF₂ · 0.55MgF₂) _y system is revealed. The conclusion is drawn that, in the structure of the glasses under investigation, trivalent gadolinium atoms form structural units characteristic of mixed gadolinium and aluminum oxides. Original Russian Text ? S.A. Nemov, A.V. Marchenko, P.P. Seregin, 2008, published in Fizika i Khimiya Stekla.     

Synthesis and structural characterization of [(μ-H)Ru3(CO)8{μ-S(CH2)3SH}(μ-dppe)] and [Ru3(CO)5{μ2-S(CH2)3S}2(η2-dppe)] (dppe=Ph2PCH2CH2PPh2)

The reaction of 1,3-propanedithiol with [Ru₃(CO)₁₀(μ-dppe)] (2) at 66°C afforded the thiolate complexes [(μ-H)Ru₃(CO)₈{μ-S(CH₂)₃SH}(μ-dppe)] (6) and [Ru₃(CO)₅{μ₂-S(CH₂)₃S}₂(η²-dppe)] (7) in 25 and 23% yields respectively. Compound 6 is formed by simple oxidative addition of one of the S–H bonds of 1,3-propanedithiol while the structurally unique 7 consists of an open triruthenium cluster with four terminal and one asymmetrically bridged carbonyl groups, two doubly bridged propanedithiolate ligands and a chelating dppe ligand.     

Synthesis and characterization of MgAl2O4–ZrO2 composites

Different types of dense 5–97% ZrO₂–MgAl₂O₄ composites have been prepared using a MgAl₂O₄ spinel obtained by calcining a stoichiometric mixture of aluminium tri-hydroxide and caustic MgO at 1300 °C for 1 h, and a commercial yttria partially stabilized zirconia (YPSZ) powder as starting raw materials by sintering at various temperatures ranging from 1500 to 1650 °C for 2 h. The characteristics of the MgAl₂O₄ spinel, the YPSZ powder and the various sintered products were determined by X-ray diffraction (XRD), scanning electron microscopy (SEM), BET surface area, particle size analysis, Archimedes principle, and Vickers indentation method. Characterization results revealed that the YPSZ addition increases the sintering ability, fracture toughness and hardness of MgAl₂O₄ spinel, whereas, the MgAl₂O₄ spinel hampered the sintering ability of YPSZ when sintered at elevated temperatures. A 20-wt.% YPSZ was found to be sufficient to increase the hardness and fracture toughness of MgAl₂O₄ spinel from 406 to 1314 Hv and 2.5 to 3.45 MPa m^1/2, respectively, when sintered at 1600 °C for 2 h.     

Cu2(NO3)(OH)3催化过硫酸盐降解苯酚

基于过硫酸盐的高级氧化工艺在高浓度含酚废水处理中引起了越来越多的关注。我们研究了Cu₂（NO₃）（OH）₃和过硫酸盐对于废水中苯酚的降解效果和机理。结果表明,Cu₂（NO₃）（OH）₃-过硫酸盐体系在较广泛的pH条件下（pH值为5.0~10.0）对苯酚的降解效率均较高。溶液中的总有机碳（TOC）分析表明,在pH值为8.0,1 g·L^-1过硫酸盐和1 g·L^-1 Cu₂（NO₃）（OH）₃条件下,该体系可在4 h内将初始浓度为100 mg·L^-1的苯酚完全矿化而没有产生二次污染。猝灭剂实验和电子顺磁共振（EPR）分析进一步证实Cu₂（NO₃）（OH）₃-过硫酸盐体系中的主要氧化物种是O₂^·-、SO₄^·-和¹O₂。     

Synthesis,characterization and weak ferromagnetic coupling in [Cu2(μ3-CO3)(SCN)2(py)4]n

The crystal structure of a novel [Cu₂(μ₃-CO₃)(SCN)₂(py)₄]_n complex has been determined. It comprises of [CuCO₃Cu]_n infinite chains, running along the a-axis, and is in this aspect similar to the previously described [Cu(CO₃)(4-aminopyridine)₂]·H₂O complex. The FTIR spectrum of [Cu₂(μ₃-CO₃)(SCN)₂(py)₄]_n has been recorded and analyzed. A CuCO₃Cu intrachain coupling between Cu(II) atoms has been found to be responsible for the weak ferromagnetic properties of [Cu₂(μ₃-CO₃)(SCN)₂(py)₄]_n.     

配合物[Cd（ttcH2）2（3-bpt）2]·2H2O的合成、结构及性质研究

采用常温搅拌法合成了2,3,6-三巯基均三嗪(ttcH3)和4-氨基-3,5-二(3-吡啶基)-1,2,4-三唑(3-bpt)与过渡金属镉的配合物[Cd(ttcH2)2(3-bpt)2]·2H2O,对其结构进行了X-射线单晶衍射、红外光谱、元素分析以及热重分析等表征。X-射线单晶衍射分析显示该配合物为单核,属于三斜晶系,空间群P-1。配合物在氢键作用下拓展为3D超分子网络结构。热重分析显示该配合物的骨架稳定性较好。     

Effect of the B2O3 addition on the sintering behavior and microwave dielectric properties of Ba3(VO4)2–Zn1.87SiO3.87 composite ceramics

The effect of the B₂O₃ addition on the low-temperature sintering, microstructure and microwave dielectric properties of the Ba₃(VO₄)₂–Zn_1.87SiO_3.87 composite ceramics was investigated. The results indicate that the addition of B₂O₃ can effectively promote the densification and further improve the microwave dielectric properties of the composite. The low-temperature sintering mechanism was ascribed to the formation of the liquid phase owing to the reaction between the additive B₂O₃ and the residual SiO₂ in the composite. B₂O₃–SiO₂ liquid phases can not only lower the sintering temperature, but also speed up the grain growth of the composite ceramics. The rapid grain growth occurs as the B₂O₃ content is more than 6 wt%. The 3 wt% B₂O₃ doped 0.5Ba₃(VO₄)₂–0.5Zn_1.87SiO_3.87 ceramics can be well sintered at 925 °C and exhibit excellent microwave dielectric properties of Q×f∼40,800 GHz, ε_r∼10 and τ_f∼0.5 ppm/°C.     

离子液体[BMIM]3[CB3GA]萃取溶菌酶的影响因素分析

以离子液体[BMIM]3[CB3GA]作为萃取剂在不同操作条件下进行溶菌酶萃取实验。结果表明,[BMIM]3[CB3GA]离子液体的浓度为4 mmol/L、萃取时间为30 min及溶液呈酸性时,对溶菌酶的萃取效果最佳,可达90%以上;多次回收离子液体进行重复萃取时,[BMIM]3[CB3GA]对溶菌酶的萃取率无明显下降,也可维持在90%以上。     

Sr0.5Zr2(PO4)3陶瓷的力学性能研究

用共沉淀法和低分子有机溶剂分散获得SZP粉体,经干压成型和烧结得到SZP陶瓷.研究了其力学性能与烧结温度烧结时间和添加剂用量的关系.最佳工艺条件为添加MgO6wt%,1300℃或ZnO3wt%,1200℃均烧结1.5小时,SZP陶瓷的抗压强度分别可达244.0MPa和226.2MPa.