Synthesis and structural refinement of fully dehydrated fully Zn<Superscript>2+</Superscript>-exchanged zeolite Y (FAU), |Zn<Subscript>35.5</Subscript>|[Si<Subscript>121</Subscript>Al<Subscript>71</Subscript>O<Subscript>384</Subscript>]-FAU

The single-crystal structure of |Zn_35.5|[Si₁₂₁Al₇₁O₃₈₄]-FAU per unit cell, a = 24.794(1), dehydrated at 673 K and 1 × 10^?6 Torr, has been determined by single-crystal X-ray diffraction techniques in the space group \( Fd\bar{3}m \) at 294(1) K. The structure was refined using all intensities to the final error indices (using the 930 reflections for which F _o > 4σ(F _o)) R ₁ = 0.0448 (based on F) and wR ₂ = 0.1545 (based on F ²). About 35.5 Zn²⁺ ions per unit cell are found at an unusually large number of crystallographic distinct positions, six. The 0.5 Zn²⁺ ion per unit cell is located at the center of double 6-ring (D6R, site I; Zn(I)-O(3) = 2.642(3) Å and O(3)-Zn(I)-O(3) = 81.23(12) and 98.77(12)°). Two different site-I′ positions (in the sodalite cavities opposite D6Rs) are occupied by 14 and 3 Zn²⁺ ions per unit cell, respectively; these Zn²⁺ ions are recessed 0.67 Å and 1.02 Å, respectively, into the sodalite cavities from their 3-oxygens plane (Zn(I′a)-O(3) = 2.094(3) Å, Zn(I′b)-O(3) = 2.23(5) Å, O(3)-Zn(I′a)-O(3) = 110.32(12)°, and O(3)-Zn(I′b)-O(3) = 100.9(30)°). Site-II′ positions (in the sodalite cavities opposite S6Rs) are occupied by 6 Zn²⁺ ions, each of which extends 0.63 Å into the sodalite cavities from their 3-oxygens plane (Zn(II′)-O(2) = 2.164(3) Å and O(2)-Zn(II′)-O(2) = 112.00(12)°). Twelve Zn²⁺ ions are found at two nonequivalent sites II (in the supercage) with occupancies of 7 and 5 ions, respectively; these Zn²⁺ ions are recessed 0.52 Å and 0.96 Å, respectively, into the supercage from their 3-oxygens plane (Zn(IIa)-O(2) = 2.138(12) Å, Zn(IIb)-O(2) = 2.28(4) Å, O(2)-Zn(IIa)-O(2) = 114.2(10)°, and O(2)-Zn(IIb)-O(2) = 103.7(25)°).     

Structure of a methylamine sorption complex of fully dehydrated Cd-exchanged zeolite X, Cd46(CH3NH2)16[Si100Al92O384]-FAU

The structure of a methylamine sorption complex of fully dehydrated, fully Cd²⁺-exchanged zeolite X, Cd₄₆(CH₃NH₂)₁₆[Si₁₀₀Al₉₂O₃₈₄]-FAU (a = 24.863(4) Å), has been determined by single-crystal X-ray diffraction techniques in the cubic space group at 21(1) °C. An aqueous exchange solution 0.05 M in Cd²⁺ was allowed to flow past the crystal for 5 days. The crystal was then dehydrated at 480 °C and 2 × 10⁻⁶ Torr for 2 days (colorless), and exposed to 160 Torr of methylamine gas at 21(1) °C for 2 h (yellow). Diffraction data were then gathered in this atmosphere and were refined using all data to the final error indices (based upon the 524 reflections for which F_o > 4σ(F_o)) of R₁ = 0.069 and wR₂ = 0.200. In this structure, Cd²⁺ ions occupy three crystallographic sites. The octahedral sites I at the centers of the hexagonal prisms are filled with 16 Cd²⁺ ions per unit cell (Cd–O = 2.369(8) Å). The remaining 30 Cd²⁺ ions are located at two non-equivalent sites II with occupancies of 14 and 16. The 16 methylamine molecules per unit cell lie in the supercage where each interacts with one of the latter 16 site-II Cd²⁺ ions: N–Cd = 2.11(8) Å. The imprecisely determined N–C bond length, 1.49(22) Å, agrees with that in gaseous methylamine, 1.474 Å. The positions of the hydrogen atoms were calculated. It appears that one of the amino hydrogen atoms hydrogen bonds to a 6-ring oxygen, and that the other forms a bifurcated hydrogen bond to this and another 6-ring oxygen. The methyl group is not involved in hydrogen bonding.     

A mixed-type of azametallacrown containing [Mn6(pnhz)6(DMF)4(H2O)2] and [Mn6(pnhz)6(DMF)2(H2O)4] constructed by a flexible pentadentate ligand

A mixed-type of azametallacrown based on a flexible pentadentate N-propionyl ligand was reported, which exhibits not only the completely different arrangement of the metal centers but also diversely geometric configurations of the N-terminal ligands, and this complex can further assemble into a novel 3-D supramolecular structure using two different aza18-MC-6 as secondary building units (SBUs) via the intermolecular C–H?π, π–π and C–H?O interactions. Temperature-dependent magnetic susceptibility measurements of the title complex indicate that the complex presents significantly antiferromagnetic coupling among metal centers.     

Observation of [Al(OH) n (H2O)6-n ] n (MoO4) in hydrotreating catalyst precursors by solid-state27 Al NMR

A previously unobserved octahedral²⁷Al MAS NMR resonance has been detected in rehydrated calcined Mo/Al₂O₃ hydrotreating catalyst precursors. This resonance is attributed to the presence of hydrated forms of aluminum molybdate such as [Al(OH) _n (H₂O)_6-n ] _n (MoO₄) (n = 1 or 2). The cross-polarization relaxation parameters, obtained from variable contact time experiments, yielded information on the relative sizes of the [Al(OH) _n (H₂O)_6-n ] _n (MoO₄) domains in the catalysts with different molybdenum loadings. Analysis of the²⁷A1 MAS NMR spectra of P-Mo(8)/Al₂O₃ and P-Mo(12)/Al₂O₃ (wt%P = 0.0–12.0) shows that a function of the phosphate in the 12 wt% Mo catalyst is to prevent the re-hydration of the molybdate phases on the calcined catalysts.     

DNA-Binding Study of Tetraaqua-bis(p-nitrobenzoato)cobalt(II) Dihydrate Complex: [Co(H2O)4(p-NO2C6H4COO)2]·2H2O

The interaction of [Co(H₂O)₄(p-NO₂C₆H₄COO)₂]^· 2H₂O with sheep genomic DNA has been investigated by spectroscopic studies and electrophoresis measurements. The interaction between cobalt(II) p-nitrobenzoate and DNA has been followed by gel electrophoresis while the concentration of the complex was increased from 0 to 14 mM. The spectroscopic study and electrophoretic experiments support the fact that the complex binds to DNA by intercalation via p-nitrobenzoate into the base pairs of DNA. The mobility of the bands decreased as the concentration of complex was increased, indicating that there was increase in interaction between the metal ion and DNA.     

[Nd(6-OHnicH)3(H2O)6]n配合物的合成和晶体结构研究

在水热反应条件下,采用6-羟基吡啶-3-甲酸(6-OHnicH)与稀土金属离子钕合成了标题化合物。运用元素分析、红外光谱、X-射线衍射等进行了表征。X-射线衍射结果表明:该配合物属于三斜晶系,空间群是P-1,晶胞参数为:a=7.1693(8),b=10.3227(12),c=16.7831(19),α=73.3000(10)°,β=88.0070(10)°,γ=88.2180(10)°,Z=2。该配合物最终通过分子间氢键作用堆积为三维网状结构。     

Re-examination of phase relations between solid solutions in R4Al2O9-R4Si2N2O7-R4Si2O10 (R=Y,Gd, Yb) systems

Samples in Si–Al-R-O-N (R = Y, Gd, Yb) systems were prepared by solid-state reactions using R₂O₃, Al₂O₃, SiO₂ and Si₃N₄ powders as starting materials. X-ray diffraction was done to investigate RAM-J(R) solid solutions [RAM = R₄Al₂O₉, J(R) = R₄Si₂N₂O₇] formation and their equilibrium with RSO (R₄Si₂O₁₀). Phase relations between RAM, J(R) and RSO at 1700 °C were summarized in a phase diagram. It was determined that a limited solid solution of RAM and RSO could be formed along RAM-RSO tie-line, while RAM and J(R) form a continuous solid solution along RAM-J(R) tie-line. In RAM-J(R)-RSO ternary systems, the RAM-J(R) tie-lines were extended towards the RSO corner to form a continuous solid solution area of JRAMss (R = Y, Gd, Yb). The established phase relations in the Si–Al-R-O-N (R = Y, Gd, Yb) systems may facilitate compositional selections for developing JRAMss as monolithic ceramics or for SiC/Si₃N₄ based composites using the solid-solutions as a second refractory phase.     

三维超分子化合物[Zn(C6H4O2N)2·(H2O)4]n的水热合成及晶体结构

用2-羧基吡啶和六水合氯化锌反应制备了一种新的三维氢键超分子配合物,经X-射线衍射分析确定了单晶结构。该晶体属单斜晶系,P2(1)/n空间群,晶胞参数为:a=9.836(2),b=5.2256(10),c=14.611(3),Mr=381.64,β=90.01(3)°,V=751.0(3)3,Z=2,Dc=1.688Mg.m-3,F(000)=392,μ=1.680mm-1,R=0.0258,wR=0.0612。共收集2159个衍射数据,其中1273个为独立衍射点(Rint=0.0332),可观测点数1139个(I>2σ(I))。结果表明,在组成该超分子体系的基本结构单元[Zn(C6H4O2N)2.(H2O)4]中,Zn(Ⅱ)离子形成六配位的畸变的八面体构型,配合物单元之间通过氢键OH…O相互连接,形成了无限延伸的具有网状结构的三维超分子体系。     

溶剂热法合成有机金属框架材料Co_2(C_8O_6H_4)_2·4H_2O

采用溶剂热法合成了一种新的金属有机配合物[Co2(C8O6H4)2·(H2O)4],通过X射线单晶衍射技术对该化合物进行了结构表征。结果表明,该化合物晶体属三斜晶系,空间群为P1;晶胞参数a=9.389(2)(1=10-10 m),b=9.421(3),c=12.209(3);α=101.846(2)°;β=104.453(2)°;γ=105.305(3)°;V=965.23;Z=2;Dc=2.003g/cm3,μ=1.810mm-1,F(000)=588,GooF=1.044,R1=0.0268,ωR2=0.023 0[I2σ(I)]。     

三维超分子化合物[Zn(C6H4O2N)2·(H2O)4]n的水热合成及晶体结构

用2-羧基吡啶和六水合氯化锌反应制备了一种新的三维氢键超分子配合物,经X-射线衍射分析确定了单晶结构.该晶体属单斜晶系,P2(1)/n空间群,晶胞参数为a=9.836(2)(A),b=5.2256(10)(A),c=14.611(3)(A),Mr=381.64,β=90.01(3)°,V=751.0(3)(A)3,Z=2,Dc=1.688Mg·m-3,F(000)=392,μ=1.680mm-1,R=0.0258,wR=0.0612.共收集2159个衍射数据,其中1273个为独立衍射点(Rint=0.0332),可观测点数1139个(I＞2σ(I)).结果表明,在组成该超分子体系的基本结构单元[Zn(C6H4O2N)2·(H2O)4]中,Zn(Ⅱ)离子形成六配位的畸变的八面体构型,配合物单元之间通过氢键OH…O相互连接,形成了无限延伸的具有网状结构的三维超分子体系.     

二维层状超分子化合物[Mn（C8H5NO6）（H2O）2]n的合成及晶体结构研究

分子间的弱相互作用在配位化合物中往往表现为配合物分子内和(或)分子间的配体间相互作用。因此,研究配合物中的配体间弱相互作用就成为由配位化学向超分子化学过渡的桥梁。本文以锰离子为中心离子,以2,4,6-吡啶三羧酸为配体进行晶体合成实验。通过检测手段了解了合成的配合物配体间的弱相互作用。     

Characterization of metal (Ba, Al, Si, V, and W)-incorporated TiO2 and toluene photodecomposition in the presence of H2O

This study focused on toluene photodecomposition in the presence of H₂O over metal (Ba, Al, Si, V, and W)-incorporated TiO₂. The nanometer-sized, metal-TiO₂ photocatalyst samples, including Ba²⁺, Al³⁺, Si⁴⁺, V⁵⁺, and W⁶⁺ ions, were prepared by using the solvothermal method. The X-ray photoelectron spectroscopy (XPS) results showed that the Ti-OH peak, which indicates hydrophilicity, increased with increasing Al and Si ion components but decreased with increasing Ba, V, and W ion components. The contact angles were distributed over the range of 0–10° on almost all films (200-nm thick) after irradiation for 2 h, and in particular approached 0° on the Al-TiO₂ and Si-TiO₂ nanometer-sized films after just 30 min. The toluene (100 ppm) photodecomposition in the continuous system increased in the order of Al-TiO₂>Si-TiO₂>pure TiO₂>W-TiO₂>Ba-TiO₂>V-TiO₂, and the maximum toluene conversion rate achieved was 45% over Al-TiO₂ film after 120 min. The toluene conversion remarkably increased; however, over all photocatalysts, with H₂O addition during the toluene photo-decomposed reaction, and in particular, the conversion reached up to 90% after 120 min over Al-TiO₂ and Si-TiO₂ with increased hydrophilicity. After photoreaction for 24 h, minimal carbon was deposited on the photocatalyst under both reaction conditions, with and without H₂O addition, although the deposited carbon amounts were smaller for the former. These results confirmed that the hydrophilicity of the photocatalyst had a greater effect on toluene decomposition, while the photocatalytic deactivation could be retarded by H₂O supplementation during toluene decomposition.     

Crystal Structure, Thermal and Magnetic Behavior of Inorganic–Organic Hybrid [VIV 4O10 VV 2O4] (C6H14N2)·H2O Polymeric Framework

Summary The inorganic–organic hybrid [V^IV ₄O₁₀V^V ₂O₄] (C₆H₁₄N₂)·H₂O polymeric framework was prepared under mild hydrothermal conditions from a mixture of DABCO and V₂O₅ in deionized water with a 1:1:450 mole ratio, at neutral pH. The reaction was carried out at 180 °C for 3 days under autogenous pressure yielding phase pure crystals product. The crystal structure was studied using both powder and single crystal X-ray crystallography, revealing the structure to be of the ({UuDd}:T*)α′ type in the SP+T class and Z-T subclass. The presence of the organic cation was confirmed by FT-IR spectrum and chemical composition analysis. The structure was thermally stable up to over 400 °C, and showed ferromagnetic character at room temperature with the maximum molar susceptibility of 8.26 × 10⁻³ emu/mol⁻¹ at zero applied field.     

Characterization of synthetic hydrocalumite-type [Ca2Al(OH)6]NO3·mH2O: Effect of the calcination temperature

A lamellar hydrocalumite-type [Ca₂Al(OH)₆]NO₃·mH₂O, (HC), was synthesized and characterized by X-ray diffraction analysis (XRD), surface area, pore size measurements, CO₂-Thermal Programmed Desorption, and later tested as catalysts in the double bond isomerization of 1-butene. The layered structure of HC collapses above 523 K yielding an amorphous material at 573 K which upon calcination at 873–973 K transforms into a mixture of CaO and mayenite Ca₁₂Al₁₄O₃₃. The calcination temperature has a marked effect in the formation of basic sites. Thus for example, HC calcined at 1073 K shows 90% of strong basic sites (CO₂ desorption at 1023 K) while they are absent in HC calcined at 573–673 K. HC calcined at 973 K shows high catalytic activity (74% conversion) in the isomerization of 1-butene without any appreciable deactivation after 4 h on stream.     

Tetra- and hexanuclear cage molecules based on diruthenium tetracarbonyl sawhorse units: Synthesis and molecular structure of [{Ru2(CO)4(PPh3)2}2(O2CCH2CO2)2] and [{Ru2(CO)4(PMe3)2}3(O2CC6H4CO2)3]

The thermal reaction of Ru₃(CO)₁₂ with malonic acid, followed by the addition of the corresponding ligand, yields the tetranuclear ruthenium complexes [{Ru₂(CO)₄L₂}₂(O₂CCH₂CO₂)₂] (L = PPh₃: 1, L = 3,5-Me₂NC₅H₃: 2), while the reaction of Ru₃(CO)₁₂ with terephthalic acid, followed by the addition of the corresponding ligand, gives rise to the formation of the hexanuclear ruthenium complexes [{Ru₂(CO)₄L₂}₃(O₂CC₆H₄CO₂)₃] (L = PMe₃: 3, L = 3,5-Me₂NC₅H₃: 4). The single-crystal X-ray structure analyses for 1 and 3, reveal both cages to consist of Ru₂(CO)₄ sawhorse units, 1 being a molecular loop, while 3 is a molecular triangle.     

Synthesis and characterization of Na4[I2(μ-O)2O6(OH)2] · 8H2O,and its catalytic epoxidation of olefins by molecular oxygen

The complex Na₄[I₂(μ-O)₂O₆(OH)₂] · 8H₂O has been synthesised and characterized by elemental analysis, Raman, infrared, electronic and ¹²⁷I NMR spectra, and thermal measurements. This complex was found to be an efficient heterogeneous catalyst for the epoxidation of linear and cyclic olefins in the presence of molecular oxygen in the absence of sacrificial reductant.     

基于Dawson型H_6P_2Mo_(18)O_(62)杂化材料[Ni(2,2'-bipy)_3]_3(P_2Mo_(18)O_(62))的制备及其吸附性能研究

以H_6P_2Mo_(18)O_(62)、[Ni(2,2'-bipy)_3]Cl_2·5.5H_2O为原料,通过化学共沉淀法制备[Ni(2,2'-bipy)_3]_3(P_2Mo_(18)O_(62))复合材料,采用FT-IR、SEM、TG、BET等手段进行表征,并研究其对亚甲基蓝(MB)溶液的吸附性能。探讨了pH、初始浓度、温度等条件对MB溶液吸附效果的影响。结果表明,将H_6P_2Mo_(18)O_(62)与[Ni(2,2'-bipy)_3]Cl_2·5.5H_2O进行复合形成复合物[Ni(2,2'-bipy)_3]_3(P_2Mo_(18)O_(62))后,可有效克服其水溶性,大大提高了其液相吸附能力,且温度对其吸附性能影响不大。从实验结果可知,复合物对MB溶液的吸附分别符合Langmuir等温吸附模型和拟二级动力学模型。热力学参数ΔG~00、ΔH~00和ΔS~00,表明该吸附剂对亚甲基蓝的吸附是自发且放热的,且对其他阳离子染料罗丹明B也有较好的吸附效果。     

Polymeric [Eu(L)3(H2O)] (HL = 1-(pyridin-4-yl)butane-1,3-dione and Dimeric [Eu2(L)6(H2O)2] (HL = 1,3-di(pyridin-3-yl)propane-1,3-dione) as selective and sensitive chemosensors for Hg(II) ion

Eu(III) complexes, [Eu(L1)₃(H₂O)] (1) and [Eu₂(L2)₆(H₂O)₂] (2) have been prepared and structurally characterized. They are highly selective and sensitive chemosensors for Hg²⁺. These Eu-containing materials show fluorescent enhancement only for Hg²⁺. The complexation of other metal ions leads to fluorescence quenching or no response.     

Homogeneous reduction of nitrobenzene to aniline under CO/H2O, catalyzed by cis-[Rh(CO)2(amine)2]PF6. The role of the amine effect

The CO₂ reforming of methane over reduced NiO/MgO solid solution catalysts was studied at 800°C by a novel transient method, which couples a broadened pulse of CH₄/CO₂ with a step change to the carrier gas and/or with a sharp isotopic pulse of either ¹⁸O₄, CO¹⁸ ₂ or ¹³CO¹⁶ ₂. The response curves indicated that two kinds of oxygen were formed over the catalysts during reaction: adsorbed oxygen which reacts fast with C species and lattice oxygen which reacts more slowly with C species. One concludes that a redox cycle of lattice oxygen formation through the oxidation of Ni and its reaction with C species takes place on the catalyst surface. This revised version was published online in August 2006 with corrections to the Cover Date.     

配合物[Ni(IDB)_2][C_6H_4(OH)COO]·ClO_4·CH_3CH_2OH·H_2O催化尿素水解的机理及其电化学性质

报道[Ni(H2O)6](ClO4)2·2H2O的合成、晶体结构,单核镍(Ⅱ)配合物[Ni(IDB)2][C6H4(OH)COO]·ClO4·CH3CH2OH·H2O[配体IDB为N,N 二(2 苯并咪唑亚甲基)胺]的电化学性质,探讨标题配合物催化尿素水解的机理。X射线单晶衍射表明,[Ni(H2O)6](ClO4)2·2H2O晶体属单斜晶系,P2(1)/C空间群,化学式:Cl2H16O16Ni,Mr=401.74,晶胞参数:a=0.62383(12)nm,b=1.2464(3)nm,c=0.91845(18)nm,α=90°,β=106.93(3)°,γ=90°,V=0.6832(2)nm3,Z=2,F(000)=412,S=1.079,DC=1.953g/cm3,μ=1.890mm-1。最终因子R[I>2σ(I)]:R1=0.0423,wR2=0.1155;R(全部数据)∶R1=0.0506,wR2=0.1180。结构分析表明,[Ni(H2O)6](ClO4)2·2H2O的镍(Ⅱ)分别与6个H2O配位形成对称的正八面体构型。循环伏安实验说明,标题配合物在DMF溶液中在E1/2=0.884V处经历了一个准可逆的一电子氧化还原过程。