Die Verbindungen 2SiO2·P2O5 und 2GeO2·P2O5

Zusammenfassung Bei röntgenographischen Untersuchungen im System GeO₂-P₂O₅ wird eine Verbindung der Zusammensetzung 2 GeO₂·P₂O₅ aufgefunden. Einkristallaufnahmen ergeben eine hexagonale (trigonale) Elementarzelle mita=7,99₈ undc=24,8₆ Å. Die schon beschriebene Verbindung 2 SiO₂·P₂O₅ erweist sich als isotyp:a=7,86₂ undc=24,1₃ Å.     

MgO-P2O5和CaO-P2O5体系的热力学优化

基于严格评估的相图和热力学实验数据,采用相图计算方法对MgO-P₂O₅和CaO-P₂O₅体系进行热力学优化.液相采用修正的似化学模型进行描述,考虑了对近似处理液相中存在的短程有序.为了描述M₃(PO₄)₂(M = Mg, Ca)组分处的最大短程有序,将PO₄^3-当作液相中P₂O₅的基本组成单元.体系中所有的中间相都看作线性化合物并考虑了晶型转变.获得一套合理、可靠、自洽的模型参数用来描述体系中各相的热力学性质,在实验误差范围内很好地重现了相图、焓、熵和活度实验数据,为炼钢脱磷过程中熔渣体系热力学数据库的建立打下了坚实的基础.     

提高Nb2O5中Ta2O5光谱分析的灵敏度

由于Ｎｂ２Ｏ５与Ｔａ２Ｏ５物理、化学性质相似，主体Ｎｂ２Ｏ５对Ｔａ分析线强度干扰很大。因此，Ｎｂ２Ｏ５中光谱测定Ｔａ２Ｏ５的灵敏度很差，为了提高Ｔａ分析线强度，通常的光谱条件选择是无效的。实验表明在旋流气室中，采用高含量Ａｒ的（Ａｒ、Ｏ２）控制气氛电弧激发，提高了Ｎｂ２Ｏ５中Ｔａ２Ｏ５的光谱分析灵敏度。然而，由于Ｎｂ２Ｏ５在高温下易于被碳还原，虽然用Ｓｔａｌｌｗｏｏｄ喷咀可以改善蒸发，减慢样品还原     

Preparation and crystal structures of [μ-SbPh2]2[Mo(CO)2(η5-C5H5)]2·CHCl3 and SbPh[Fe(CO)2(η5-C5H5)]2

Antimony is reduced when [SbPh₂BrO]₂ is treated with Na[Mo(CO)₃(η⁵-C₅H₅)] to produce [μ-SbPh₂]₂[Mo(CO)₂(η⁵-C₅H₅)]₂. A structure determination shows diphenylstibido groups bridging between two Mo(CO)₂(η⁵-C₅H₅) moieties giving a central ‘butterfly’ shaped Sb₂Mo₂ ring. The cyclopentadiene rings are trans to each other and Mo–Sb and Sb–Sb separations are both short. An iron analogue could not be obtained from [SbPh₂BrO]₂ and Na[Fe(CO)₂(η⁵-C₅H₅)] but a mixture of SbPh[Fe(CO)₂(η⁵-C₅H₅)]₂ and SbPh₂[Fe(CO)₂(η⁵-C₅H₅)] was obtained using SbPh₂Cl. An X-ray structure for SbPh[Fe(CO)₂(η⁵-C₅H₅)]₂ shows an open stibinidine structure.     

Synthesis and Structural Characterization of [(η~5-C_5Me_5)_2Mo_2Fe_2S_4Br_2]

1 INTRODUCTION We once reported a CS bond cleavage reaction of (h5-C5Me5)Mo(StBu)3, which led to a Mo(IV) thio/thiolate complex (h5-C5Me5)MoS2(StBu)[1]. This reaction was facilitated by oxidants such as S8, gray selenium, and FeCl3[2]. The reaction with FeCl3 gave rise to a cubane cluster [(h5-C5Me5)2Mo2Fe2S4Cl2], which served as an excellent building block to construct various Mo/Fe/S clusters[2]. In this paper, we report the crystal structure of [(h5-C5Me5)2Mo2Fe…     

Studies on Kinetic Properties of Active Oxygen on the Surfaces of V_2O_5/SiO_2, V_2O_5-MoO_3/SiO_2 and V_2O5-P_2O5/SiO_2 Catalysts

Applying the TPD-MS with a high sensitivity of determination, the TPD spectrum of surface oxygen of V2O5/SiO2, V2O5-MoO3/SiO2 and V2O6-P2O5/SiO2 catalysts was obtained. The surface oxygen of these catalysts can be divided into three groups according to the desorption temperature. O2- desorbs mainly from 373K. to 423K, O- from 673K to 873K and O2- at above 873K. The activation energy and frequency factor of all the three kinds of oxygen species were calculated. Based on these results, the mechanism of oxygen desorption and the influence of P2O5 and MoO3 on the properties of oxygen supply of V2O5/SiO2 catalst were investigated. MoO3 and a small amount of P2Os increase the number of supplying oxygen and increase the activity of O- species. A large amount of P2O5 increases the number of supplying oxygen and restrains the activity of O- species.     

Ni-Nb2O5和Ni-Cu-Nb2O5催化甲烷燃烧活性研究

在微型固定床反应器中考察了新型甲烷催化燃烧催化剂Ni-Nb2O5和Ni-Cu-Nb2O5的活性．实验结果表明，含Nb2O5的Ni及Ni-Cu双金属催化剂具有好的催化甲烷低温燃烧性能，其甲烷转化率与反应温度、活性组分含量和空速有关．70％Ni担载量的Ni-Nb2O5催化剂可使甲烷在500℃时完全转化，并具有稳定的催化活性．Ni-Cu-Nb2O5体系催化剂中，Ni／Cu比为65／25时催化剂具有最佳的活性；该催化剂中Nb2O5可以在一个比较宽的范围内调节，并在此调节范围内可使甲烷在550℃温度下完全转化．     

Synthesis and Characterization of syn-[(η~5-C_5Me_5)_2W_2(S)_2(μ-S)_2].0.5anti-[(η~5-C_5Me_5)_2W_2(S)_2(μ-S)_2]

1 INTRODUCTION The complexes of syn- or anti-[(5-C5Me5)2- W2(S)2(-S)2] could be prepared in several ways[1~5]. For example, a mixture consisting of [Et3NH][(5-C5Me5)WS3] and anti-[(5-C5Me5)2- W2(S)2(-S)2] was generated from the reactions of [(5-C5Me5)WCl4] with H2S in the presence of NEt3[2]. The reactions of [(5-C5Me5)W(NO)I2] with H2S led a mixture of [(5-C5Me5)W(S)(S2)I] and anti-[(5-C5Me5)2W2(S)2(-S)2][3]. [(5-C5Me5)W- (StBu)3] was degraded in THF at room temperat…     

2′,5′-寡核苷酸C_(2′P_5′)C_(2′P_5′)A的合成

近年来发现用干扰素处理过的细胞胞浆提取物和双链RNA、ATP一起培养,可以生成一个低分子量的蛋白合成抑制剂,即5′-三磷酸-三聚2′,5′-腺苷酸(Ⅰ)。由于(Ⅰ)具有天然核酸中不存在的2′,5′-磷酸酯链以及它的抗病毒活性,因此引起不少化学家的兴趣,已有不少文章报导了(Ⅰ)及其类似物的合成,同时也发现不含三磷酸的三聚2′,5′-腺苷酸(Ⅱ)也同样具有活性。为了进一步研究(Ⅰ)的结构与活性关系,本文报导了用胞嘧啶碱基代替腺嘌呤碱基的(Ⅱ)的类似物C_(2′P5′)C_(2′P5′)A(Ⅲ)的合成。     

Synthesis and Anti-inflammatory Action of （η-C5H5 ）2Ti（ Sal）2 and （η-C5H5 ）2Ti（Clo）2

IntroductionSince K pf[1]discovered that dicyclopenta die-nyltitanium dichloride possesses antitumour action in1979,a large number of cyclopentadienyltitanium com-plexes with different substituents have been synthe-sized[2,3].The experimental data reveal …     

2-(5-O-nitro-1,4:3,6-dianhydro-D-glucit-2-yloxy)-5-R-5-nitro-2-oxo-1,3,2-λ5-dioxaphosphorinanes: synthesis and structure

5,5-Disubstituted 1,3,2-dioxaphosphorinanes were synthesized by the reaction of (5-O-nitro-1,4:3,6-dianhydro-D-glucit-2-yl) phosphochloridate with 2-nitro-2-R-propane-1,3-diols in the presence of organic bases. The structure of 5-bromo-5-nitro-2-(5-O-nitro-1,4:3,6-dianhydro-d-glucit-2-yloxy)-2-oxo-1,3,2-λ⁵-dioxaphosphorinane was established by X-ray diffraction.     

Synthesis and Crystal Structure of[(2 , 4-Me_2C_5H_5)_2NdC ＝CC_6H_5]_2

ＳｙｎｔｈｅｓｉｓａｎｄＣｒｙｓｔａｌＳｔｒｕｃｔｕｒｅｏｆ［（２，４－Ｍｅ＿２Ｃ＿５Ｈ＿５）＿２ＮｄＣ＝ＣＣ＿６Ｈ＿５］＿２ＺＨＡＮＧＳｕｏ－ｂｏａｎｄＬＩＵＪｕ－ｚｈｅｎｇ（ＤｅｐａｒｔｍｅｎｔｏｆＣｈｅｍｉｓｔｒｙ，ＪｉｌｉｎＵｎｉｖｅｒｓｉｔ...     

P2O2-V2O5-TiO2的表面结构

P_2O_5-V_2O_5-TiO_2(简写为P-V-Ti)对芳烃氧化有良好的催化效果.丁烷氧化催化剂P-V体系的体相和表面结构已有一些报道.但P_2O_5对V-Ti的影响文献较少报道.本文用XRD,IR,TPD和ESR考察了P-V-Ti体系. 1.试剂和催化剂:草酸、偏钒酸铵、二氧化钛均为化学纯.将V_2O_5:TiO_2=11:89(重量)样品分别按 P/V原子比为0.1,0.3,0.6,1.0,1.5和2.5制成编号为P-0.1,P-0.3,P-O.6,P-1.0,P-1.5和P-2.5的催化剂.     

Acyldesilylation of 5-Trimethylsilyl-2-furancarboxaldehyde

5－Acyl－2－furancarboxaldehydes2arelmpol－tantIntermedlateslforsynthesizingnaturallyoccuTTingfuranoldfattyacidswhichhaveantloxldanteffectsandantlneoplastlcactlvltlesInbiologicalsystems－．Nakayamaela尸reportedsuccessfulhalodesllylatlonofethyls－trlm...     

担载Ni2（C5H5）2（CO）2催化剂的EXAFS表征

以Ni_2Cp_2(CO)_2(Cp=C_5H_5)为催化剂母体化合物,γ-Al_2O_3,SiO_2为担体制备了担载型镍催化剂,对母体化合物及热分解处理前后的催化剂样品在同步辐射装置上进行了外延X-光精细结构(Extended X-ray Absorpdon Fine Structure)测定,以先进的球面波理论对实验结果进行拟合,标样拟合结果与文献XRD完全一致。催化剂的EXAFS表征结果表明,母体化合物与氧化物担体表面发生了较强的化学作用,镍组分具有较高的分散度,镍在氧化硅表面存在Ni[(O)_8]_n,Ni—Ni两种配位,而在氧化铝表面几乎只存在Ni[(O)s)_n配位,催化剂上Ni—Ni键长比母体化合物Ni—Ni键长增加0.01nm左右,Ni—Ni键的伸长及其配位状态可能对其催化行为有重要影响。     

Molecular structure of two dicyclopentadienylmolybdenum derivatives containing a four-membered ring [Mo(η5-C5H5)2(2-NHNC5H4)][PF6] and [Mo(η5C5H5)2(2-ONC5H4)][PF6]

The structure of the new compound [Mo(η⁵-C₅H₅)₂(2-NHNC₅H₄)][PF₆] (1) has been determined. The crystals are orthorhombic, space group Pca2₁ with a 20.807(1), b 8.0030(8), c 10.056(3) Å, V 1674.5 ų, Z = 4. The structure of [Mo(η⁵-C₅H₅)₂(2-ONC₅H₄)][PF₆] (2) has also been determined. The crystals are orthorhombic, space group Pnma with a 12.727(3), b 10.174(2), c 12.918(1) Å, V 1672.8 ų, Z = 4. The structures were solved by Patterson and difference electron density syntheses and refined by least-squares to R of 0.028 for 1287 reflections for 1 and 0.059 for 1178 reflections for 2.Although not isostructural the two cationic complexes have equivalent geometries with the normal bent bismetallocene structure. For 1 the MoN bond lengths are 2.160(8) and 2.142(9) Å, with a NMoN bond angle of 59.8(3)°, whereas for 2 MoO is 2.142(10), MoN is 2.138(11) Å, the NMoO angle is 61.2(4)°. These parameters are discussed and compared with the corresponding data for similar biscyclopentadienyl complexes of molybdenum(IV). Extended Hückel molecular orbital calculations have been carried out to throw light on the nature of the bonding between the metal and the bidentate ligand.     

Synthesis and structure of bismuth-containing complexes [Ph3PMe] 2 + [BiI5]2− and [Ph3PMe] 2 + [BiI5 · C5H5N]2− · C5H5N

The complexes [Ph₃PMe] ₂ ⁺ [BiI₅]^2? (I) and [Ph₃PMe] ₂ ⁺ [BiI₅ · C ₅H₅N]^2? · C ₅H₅N (II) were synthesized by the reaction of bismuth triiodide with triphenylmethylphosphonium iodide, and their structures were determined by X-ray diffraction analysis. The P atom in cation I has slightly distorted tetragonal coordination polyhedron (the CPC angles 109.42(4)° and 109.52(4)°, the bond lengths P-C_Ph 1.779(2), P-C_Me 1.793(1) Å. The Bi atom in the anion of complex I has an ideal trigonal-bipyramidal coordination polyhedron (Bi-I_eq 3.0031(4), Bi-I_eq 3.0485(5) Å). The crystal of complex II consists of the anions [BiI₅ · C ₅H₅N]^2?, solvated pyridine molecules, and two types of crystallographically independent tetrahedral triphenylmethylphosphonium cations (the angles CPC 106.9(1)°–111.7(1)°, the distances P-C_Ph 1.785(3)–1.792(3), P-C_Me 1.793(3), 1.786(3) Å). The Bi atoms in the anion of complex II have a distorted octahedral coordination polyhedron (Bi-I 3.0878(4)–3.1240(3), Bi-N(1) 2.628(3) Å).     

Triphospha-Ferrocenes as Ligands. Crystal Structures of [Fe(η5-C5Me5)(η5-C2 TBu2P3)M(CO)5)], (M= Cr,MO, W) and the Novel ruthenium and Nickel Complexes [Fe(η5-C5Me5) (η5-C2 TBu2P3)Ru3(CO)9] and [Fe(η5-C5Me5)(η5-C2 tBu2P3)Ni(Co)2]2

Abstract

Syntheses and structures of penta- and hexaphosphorus analogues of ferrocene have been described recently¹. Unlike their simple ferrocene analogues, these complexes have further ligating potential towards other transition metal centres by virtue of the availability of the ring phosphorus lone-pair electrons that are not involved in the η⁵-coordination. We now describe the first examples of coordination compounds of the triphospha-ferrocene [Fe(η⁵-C₅Me₅) (η⁵-C₂ ^tBu₂P₃]. In the ruthenium complex [Fe(η⁵-C₅Me₅)(η⁵-C₂ ^tBu₂P₃) Ru₃(CO)₉] ² two adjacent phosphorus atoms of the η⁵-C₂ ^tBu₂P₃ ring are interlinked by a ruthenium carbonyl cluster in which all three ruthenium atoms interact with the phosphorus atoms. The tetrametallic nickel complex [Fe(η⁵-C₅Me₅)(η⁵-C₂ ^tBu₂P₃)Ni(CO)₂]₂ ³ represents the first example of intermolecular interlinkage of two phospha-ferrocene systems by two metal centres.     

负载型复合半导体V2O5-TiO2/SiO2表面V2O5和TiO2的相互修饰作用

 采用表面改性法制备了负载型复合半导体材料V2O5-TiO2/SiO2,并用X射线衍射、比表面积测定、拉曼光谱、程序升温还原和紫外-可见漫反射光谱等技术对固体材料的结构和光响应性能进行了表征. 结果表明,V2O5和TiO2在负载型复合半导体V2O5-TiO2/SiO2表面有相互修饰的作用. 一方面,V2O5能扩展TiO2的光响应范围,使TiO2的吸光区域由紫外光区拓宽至可见光区,从而提高了复合半导体对光能的利用率; 另一方面,TiO2则有助于提高V2O5在载体表面的分散程度,抑制VOx的聚合,减小V2O5的微晶尺寸,提高固体材料的能隙值和氧化还原能力.