磁性固体超强酸SO42-/ZrO2-Al2O3-Fe3O4的制备与性能研究

利用化学共沉淀法将磁性基质与固体酸组装制备磁性纳米固体超强酸催化剂，利用XRD、Raman、TG-DSC、M?ssbauer、TEM、HRTEM等手段对样品性质进行表征。结果表明：磁性基质的引入赋予固体超强酸以超顺磁性；Fe₃O₄、Al₂O₃粒子弥散在ZrO₂基质中，烧结过程中阻碍了扩散传质的进行以及晶界移动，抑制了ZrO₂晶体生长，稳定了四方晶相(T-ZrO₂)；样品粒径分布集中，平均约为32 nm；HRTEM显示T-ZrO₂晶体生长取向于(101)方向，晶面间距d(101)=0.29 nm；Hammett指示剂法测得经600 ℃焙烧后产物的酸强度H_o＜-13.8，酸强度大于浓硫酸(H_o=-11.93)。以柠檬酸三丁酯的合成作为磁性固体超强酸SO₄^2-/ZrO₂-Al₂O₃-Fe₃O₄催化剂的探针反应，结果表明外磁场的引入提高了柠檬酸的转化率。     

Synthesis and structure of C17H22FN3O 32+ ?CuCl 42-

A new compound C₁₇H₂₂FN₃O₃ ²⁺ • CuCl₄ ^2- [pefloxacindium tetrachlorocuprate(II)], C₁₇H₂₀FN₃O₃ — 1-ethyl-6-fluoro-1,4-dihydro-4-oxo-7-(4-methyl-1-piperazinyl)-3-quinoline carboxylic acid (pefloxacin, PefH) is synthesized and characterized by single crystal X-ray diffraction technique. The crystal structure of the compound contains one PefH₃ ²⁺ cation and one CuCl₄ ^2- anion. The supramolecular architecture of the crystal is determined.     

Synthesis and structure of cobalt complexes [Me3EtN] 2+ [CoI4]2? and [Me3BuN] 2+ [CoI4]2?

Complexes [Me₃EtN]₂⁺[CoI₄]²⁻ (I) and [Me₃EtN]₂⁺[CoI₄]²⁻ (II) were synthesized by reacting trimethylalkylammonium iodide with cobalt(II) iodide in acetone. According to X-ray diffraction data, complexes I and II consist of tetrahedral tetraalkylammonium cations (for I, N-C is 1.481(5)–1.590(8) CNC is 107.3(3)°–111.6(3)°; for II, N-C is 1.485(8)–1.506(10) ? and CNC is 106.9(7)°–111.7(5)°) and [CoI₄]²⁻ anions (for I, Co-I is 2.5951(5)–2.6127(5) ? and ICoI is 104.67(2)°–113.23(2)°; for II, Co-I is 2.5914(8)–2.5943(9) ? and ICoI is 107.05(2)°–114.42(5)°).     

Crystal structure of pefloxancindium tetrabromidozinkate C17H22FN3O 32+ · ZnBr 42?

A new compound, namely pefloxancindium tetrabromidozincateC₁₇H₂₂FN₃O₃²⁺ · ZnBr₄²⁺ where C₁₇H₂₀FN₃O₃ is 1-ethyl-N-methyl-6-fluoro-1,4-dihydro-4-oxo-7-(4-methyl-1-piperazinyl)-3-quinoline carboxylic acid (PefH, pefloxacin), has been synthesized and its crystal and molecular structure has been solved. It contains PefH₃²⁺ and ZnBr₄²⁻ ions. The latter is a slightly distorted tetrahedron. The supramolecular architecture of a crystal has been analyzed.     

Unusual ion UO4? formed upon collision induced dissociation of [UO2(NO3)3]?, [UO2(ClO4)3]?, [UO2(CH3COO)3]? ions

The following ions [UO₂(NO₃)₃]⁻, [UO₂(ClO₄)₃]⁻, [UO₂(CH₃COO)₃]⁻ were generated from respective salts (UO₂(NO₃)₂, UO₂(ClO₄)₃, UO₂(CH3COO)2) by laser desorption/ionization (LDI). Collision induced dissociation of the ions has led, among others, to the formation of UO₄ ⁻ ion (m/z 302). The undertaken quantum mechanical calculations showed this ion is most likely to possess square planar geometry as suggested by MP2 results or strongly deformed geometry in between tetrahedral and square planar as indicated by DFT results. Interestingly, geometrical parameters and analysis of electron density suggest it is an U^VI compound, in which oxygen atoms bear unpaired electron and negative charge.     

S2O82-/TiO2-Al2O3催化水解花生壳制备乙酰丙酸的研究

采用沉淀-浸渍法制备了不同金属配比的S2O82-/TiO2-Al2O3固体超强酸催化剂,并研究了其在催化水解花生壳制备乙酰丙酸反应中的作用。实验发现n(Al)∶n(Ti)=1∶2时催化效果最佳,并进一步考察了其水解温度,水解时间,固体酸用量和液固比对乙酰丙酸得率的影响。采用响应面法对水解工艺进行了优化,并建立二次回归模型。结果表明,当水解温度为235℃、水解时间为30min、固体酸用量为4.6%和液固比18∶1(mL/g)时为较优的制备工艺,在该工艺条件下,乙酰丙酸得率为26.43%。     

Die halbquantitative Bestimmung von Cl?, Br?, J?, SCN?, AsO43?, Cr2O72? und [Fe(CN)6]3?

Ohne Zusammenfassung     

Synthesis and structure of cobalt complexes [Ph3(n-Pr)P 2+ [CoI4]2? and [Ph3(n-Am)P 2+ [CoI4]2?

Complexes Ph₃(n-Pr)P₂⁺[CoI₄]²⁻ (I) and [Ph₃(n-Am)P]₂⁺ [CoI₄]²⁻ (II) were synthesized by reactions of triphenyl(alkyl)phosphonium iodide with cobalt(II) iodide in acetone. According to the X-ray diffraction data, complexes I and II consist of tetrahedral triphenyl(alkyl)phosphonium cations (for I, P-C is 1.787(4)–1.804(4) ? and CPC is 106.73(18)°–111.4(18)°; for II P-C is 1.786(6)–1.802(6) ? and CPC is 107.6(3)°–111.7(3)°) and [CoI₄]²⁻ anions (Co-I 2.5923(6)–2.6189(6) ?, ICoI 101.86(2)°–113.25(2)° for I; Co-I 2.5899(9)–2.6171(9) 107.01(3)°–110.47(3)° for II).     

Structure of the C17H20FN3O 32+ ·2HSO 4? · H2O compound

A new compound of C₁₇H₂₀FN₃O₃²⁺ · 2HSO₄⁻·H₂O [ciprofloxacindi-um bis(hydrosulfate) monohydrate], C₁₇H₁₈FN₃O₃ 1-cyclopropyl-6-fluoro-1,4-dihydro-4-oxo-7-(1-piperazinyl)-3-quinolinecarboxylic acid (CfH, ciprofloxacin) is obtained and its crystal structure is determined. The crystal contains CfH₃²⁺ and HSO₄⁻ ions and crystallization water molecules. Hydrogen (H3), which forms an intramolecular hydrogen bond with oxygen O2 of the carboxyl group, is attached to the carbonyl O1 atom. Hydrogen H4 of the carboxyl group is hydrogen bonded to the crystallization water molecule which links CfH₃²⁺ with two HSO₄⁻ groups by hydrogen bonds. Both H atoms at N3 of the piperazine ring form hydrogen bonds with two oxygen atoms of other HSO₄⁻ anions. Intramolecular hydrogen bonds of two types are present in the CfH₃²⁺ cation. One of them forms a six-membered ring, bonding O1 and O2 atoms, while the other, also enclosing a six-membered ring, links fluorine and carbon C14 atoms. Original Russian Text Copyright ? 2009 by A. D. Vasiliev, N. N. Golovnev, and I. A. Baidina __________ Translated from Zhurnal Strukturnoi Khimii, Vol. 50, No. 1, pp. 165–168, January–February, 2009.     

Crystal structure of C17H20FN3O 32+ ·CuBr 42? ·H2O

A new compound C₁₇H₂₀FN₃O₃²⁺·CuBr₄²⁻·H₂O is synthesized in the crystal form, where C₁₇H₁₈FN₃O₃ (CfH, ciprofloxacin) is 4-oxo-7-(1-piperazinyl)-6-fluoro-1-cyclopropyl-1,4-dihydroquinoline-3-carboxylic acid. Crystallographic data of ciprofloxacinium tetrabromocuprate(II) monohydrate, C₁₇H₂₂Br₄CuFN₃O₄: a = 8.214(1) ?, b = 10.781(2) ?, c = 13.703(2) ?, α = 85.144(2)°, β = 79.119(2)°, γ = 84.018(2)°, V = 1182.5(4) ?³, P [`1]\bar 1 space group, Z = 2. Supramolecular architecture of the crystal differs from that established for C₁₇H₂₀FN₃O₃²⁺·CuCl₄²⁻·H₂O by the absence of π-π interactions of the aromatic rings of CfH₃²⁺ ions and also the structural motifs formed by intermolecular hydrogen bonds.     

Molecular and crystal structures of [FeCl(HMPA)3(H2O)2]2+(FeCl4) 2? · 3HMPA

IR and single-crystal X-ray diffraction study are carried out for compound, C₃₆H₁₁₂Cl₉Fe₃N₁₈O₈P₆(I). It crystallizes in the orthorhombic space group P2₁2₁2₁ with a = 14.2992(3), b = 21.4351(4), c = 25.5407(5) ?, V = 7828.3(3) ?³, ρ_calcd = 1.553 g/cm³, Z = 4. The FeCl fragment is coordinated with chlorine atom of two water molecules and three HMPA molecules to form a cation, with a distorted octahedral coordinate geometry. In the crystal I, the cation is linked with HMPA by the O-H…O hydrogen bond. The chiral crystal is formed through self-assembly even from achiral molecules.     

Structure and thermal properties of [RhPy4Cl2]X complex salts (X = Cl?, ReO 4? , ClO 4? )

[RhPy₄Cl₂]Cl·4H₂O (I), [RhPy₄Cl₂]ReO₄ (II), [RhPy₄Cl₂]ClO₄ (III), and [RhPy₄Cl₂]ReO₄·2H₂O complex salts were synthesized. The crystal structure of compounds II (P4/ncc, a = 25.5655(3) ?, c = 14.3521(4) ?), III (P2₁/n, a = 13.5308(3) ?, b = 15.1044(5) ?, c = 23.3457(8) ?, β = 93.327°), and dyhydrate of II (Pbcm, a = 10.6199(9) ?, b = 10.4964(9) ?, c = 22.9834(16)?) was determined by X-ray diffraction analysis. The thermal transformations of the complexes were studied by differential thermal analysis. The substances were characterized by IR spectroscopy, XRPA, and element analysis Original Russian Text Copyright ? 2009 by D. B. Vasilchenko, I. A. Baidina, E. Yu. Filatov, and S. V. Korenev __________ Translated from Zhurnal Strukturnoi Khimii, Vol. 50, No. 2, pp. 349–356, March–April, 2009.     

Hypervalence and the delocalizing versus localizing propensities of H 3– , Li 3– , CH 5– and SiH 5–

Lithium and silicon have the capability to form hypervalent structures, such as Li₃^– and SiH₅^–, which is contrasted by the absence of this capability in hydrogen and carbon, as exemplified by H₃^– and CH₅^– which, although isoelectronic to the former two species, have a distortive, bond-localizing propensity. This well-known fact is nicely confirmed in our DFT study at BP86/TZ2P. We furthermore show that the hypervalence of Li and Si neither originates from the availability of low-energy 2p and 3d AOs, respectively, nor from differences in the bonding pattern of the valence molecular orbitals; there is, in all cases, a 3-center-4-electron bond in the axial X–A–X unit. Instead, we find that the discriminating factor is the smaller effective size of C compared to the larger Si atom, and the resulting lack of space around the former. Interestingly, a similar steric mechanism is responsible for the difference in bonding capabilities between H and the effectively larger Li atom. This is so, despite the fact that the substituents in the corresponding symmetric and linear dicoordinate H₃^– and Li₃^– are on opposite sides of the central atom. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.

Solid state synthesis of CuFe2O4 from Cu(OH)2?·?CuCO3–4FeC2O4?·?2H2O mixtures: mechanism of reaction and thermal characterization of CuFe2O4

Copper Ferrite has been prepared by solid state synthesis of milled mixtures of copper basic carbonate [Cu(OH)₂ · CuCO₃] and iron (II) oxalate dihydrate [FeC₂O₄ · 2H₂O]. The reaction mechanism has been studied by simultaneous TG/DSC analysis: the different steps of the mass loss process have been individuated along with the relevant enthalpy terms starting from both physical and mechanically activated mixtures. CuFe₂O₄ has been synthesized by annealing the mechanically activated mixture at 750–800 °C while no pure CuFe₂O₄ is obtained by annealing the physical mixture at temperatures as high as 1100 °C. CuFe₂O₄ has been characterized as concerns the molar het capacity, the tetragonal–cubic transition enthalpy and the Curie point.     

Cu/SO42-/La2O3-ZrO2-Al2O3催化剂的制备及其对C3H6选择还原NO的催化性能

以Al₂O₃为基质，添加ZrO₂和La₂O₃，制成La₂O₃-ZrO₂-Al₂O₃复合载体，然后采用SO₄^2-进行改性，再负载上Cu²⁺，制备了铜基SO₄^2-改性的复合载体催化剂(Cu/SO₄^2-/La₂O₃-ZrO₂-Al₂O₃)。考察了它在富氧条件下对丙烯选择还原NO的催化性能，并借助XRD、SEM、TG、Py-IR、NH₃-TPD、FTIR和TPR等方法研究了Cu/SO₄^2-/La₂O₃-ZrO₂-Al₂O₃的结构和性能的关系。结果表明，ZrO₂的加入主要有利于提高催化剂的低温活性；La₂O₃的加入则主要有利于提高催化剂的热稳定性和还原性能；SO₄^2-能够与Zr形成螯合双配位结构，大幅度促使催化剂表面酸量增加并且酸性增强；因此，有效地提高了Cu/SO₄^2-/La₂O₃-ZrO₂-Al₂O₃在富氧条件下对丙烯选择还原NO的催化活性和水热稳定性。在无水条件下，Cu/SO₄^2-/La₂O₃-ZrO₂-Al₂O₃能使NO的最大转化率高达84.3%，即使在275 ℃ 10%水蒸气存在的情况下，仍能使NO的转化率高达81.2%。     

Ionophoretische Trennung von ReCl62?, ReBr62? und ReO4?

Zusammenfassung Es wurde die ionophoretische Trennung von ReCl₆ ^2–, ReBr₆ ^2– und ReO₄ ^– unter Verwendung verschiedener Papiersorten untersucht. Am geeignetsten erwies sich das Papier 2045 b Gl von Schl. & Sch.

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Summary The ionophoretic separation of ReCl₆ ^2–, ReBr₆ ^2–, and ReO₄ ^– has been examined using different kinds of paper. Best results have been obtained with the paper 2045 b Gl from Schleicher & Schüll.

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Herrn Prof. G. Brauer danke ich für Förderung. Für die Überlassung von Rheniumverbindungen bin ich der Fa. W. C. Heraeus, Hanau, verpflichtet. Die Neutronenaktivierung wurde freundlicherweise von den Herren Dr. Marth und Dr. Köhler von der Reaktorstation in Garching bei München vorgenommen. Das Bundesministerium für Atomkernenergie und Wasserwirtschaft unterstützte die Untersuchung durch eine Sachbeihilfe.     

Theoretical studies on anionic clusters of sulfate anions and carbon dioxide, SO 4?1/?2 (CO2)n, n?=?1?4

Geometry optimizations were performed on monoanionic and dianionic clusters of sulfate anions with carbon dioxide, SO₄^−1/−2(CO₂) _n , for n = 1–4, using the B3PW91 density functional method with the 6-311 + G(3df) basis set. Limited calculations were carried out with the CCSD(T) and MP2 methods. Binding energies, as well as adiabatic and vertical electron detachment energies, were calculated. No covalent bonding is seen for monoanionic clusters, with O₃SO–CO₂ bond distances between 2.8 and 3.0 ?. Dianionic clusters show covalent bonding of type [O₃S–O–CO₂]⁻², [O₃S–O–C(O)O–CO₂]⁻², and [O₂C–O–S(O₂)–O–CO₂]⁻², where one or two oxygens of SO₄⁻² are shared with CO₂. Starting with n = 2, the dianionic clusters become adiabatically more stable than the corresponding monoanionic ones. Comparison with SO₄^−1/−2(SO₂) _n and CO₃^−1/−2(SO₂) _n clusters, the binding energies are smaller for the present SO₄^−1/−2(CO₂) _n systems, while stabilization of the dianion occurs at n = 2 for both SO₄⁻²(CO₂) _n and SO₄⁻²(SO₂) _n , but only at n = 3 for CO₃⁻²(SO₂) _n .     

Complex formation in Nb6O 198? -WO 42? -H+-H2O system where cNb: cW = 4 : 2

Processes occurring in Nb₆O₁₉⁸⁻-WO₄²⁻-H⁺-H₂O system where c _Nb: c _W = 4: 2, c _Nb+W⁰ = 5 × 10⁻³, 2.5 × 10⁻³, or 10⁻³ mol/L, and ionic strengths I = 0.01–0.14 are created by NaCl background electrolyte were studied by pH titration and mathematical modeling. Solute ion species distribution diagrams were obtained for $ Z = \frac{{c_{H^ + }^0 }} {{c_{Nb + W}^0 }} = 0 - 1.5 $ Z = \frac{{c_{H^ + }^0 }} {{c_{Nb + W}^0 }} = 0 - 1.5 . The concentration constants and thermodynamic constants of formation were calculated for isopolyniobotungstate anions (IPNTAs). H _x Nb₄W₂O₁₉^(6−x)−, (x = 1–5), ions were shown to appear in solution only after Nb₆O₁₉⁸⁻ was protonated and aquapolytungstate anions were formed. The results of modeling were supported by the synthesis of Tl₃H₃Nb₄W₂O₁₉ · 16.5H₂O, Tl₂H₄Nb₄W₂O₁₉ · 11H₂O, and NaTl₃(H₄Nb₄W₂O₁₉)₂ · 22H₂O salts, which were identified by chemical analysis and IR spectroscopy.     

ZrO4/SiO2-Al2O3催化肉桂醛MPV转移加氢性能

以九水合硝酸铝（Al（NO₃）₃·9H₂O）与正硅酸乙酯（TEOS）为前驱盐,采用溶胶-凝胶法制备一系列不同Al₂O₃含量的SiO₂-Al₂O₃复合氧化物,并通过浸渍硝酸氧锆引入ZrO₂,制备ZrO₂/SiO₂-Al₂O₃复合氧化物催化剂,考察催化剂在肉桂醛（CAL）MPV转移加氢中的催化性能,并结合N₂物理吸附、X射线粉末衍射（XRD）、傅里叶变换红外光谱（FTIR）、NH₃-程度升温脱附（NH₃-TPD）、Py-原位红外（Py-IR）等技术,研究催化剂结构、织构以及表面性质与其催化性能间的构效关系.研究表明,所制备的催化剂均以L酸为主,并含有少量B酸中心,这使得加氢产物以肉桂醇（COL）为主,并含有少量1-苯丙烯-2-丙基醚（CPE）.Al₂O₃含量不仅影响催化剂表面的酸中心数量,而且对催化剂的织构参数有较大影响.随Al₂O₃含量的增加,催化剂表面L酸与B酸中心均有所增加,而孔径则持续变小,这使得催化反应呈现CAL转化率先增加后减少、目标产物COL选择性先稍有减小后有所增加的趋势.在Si/Al比为2时,催化剂具有最优的催化性能,优化反应条件下,CAL转化率达96%,目标产物COL选择性达90%.