THE SYNTHESIS AND CRYSTAL STRUCTURE OF Mo_3(μ_3-O)-(μ-S)_3(μ-OOCCH_3)(dtp)_3(Py)

<正> The title compound was obtained by the reaction of Mo3(μ3-O) (μ-S)3(dtp)4(H2O) with CH3COONa and pyridine. Mo3C19H38N1O9P3S9,Mr= 1093. 79, triclinic, space group P1, a = 12. 921(3) , b = 14. 260(3) , c= 12. 800(3)(?),α = 97. 54(2), β=116. 66(1), γ=100. 10(2) °, V = 2015, 2(8)(?)3, Z=2, Dc = 1. 80gcm-3, F(000) = 1092, final R = 0. 066 for 3444 observations, room temp. In the structure the three Mo atoms form an isosceles triangle capped by a μ3-O atom with three sides of 2. 589(2) , 2. 642(2), and 2. 627(2) (?) respectively, and the car-boxyl bridged Mo-Mo bond is the shortest one.     

CRYSTAL STRUCTURE OF [Mo_3S_4 (μ-CH_3COO) [S_2P(OEt)_2]_3 (py)] (CH_3COOCH_2CH_3)

<正> [Mo3S4(μ-CH3COO)[S2P(OEt)2]3(py)]·(CH3COOCH2CH3) , Mr = 1197. 96,monoclinic,P21/n,a=13. 158(2),b=23. 153(5), c=16. 175(3) A,β = 112. 79(1)°,V=4543. 1(7)A3,Z=4, Dc= 1. 751g/cm-3,λ(MoKa) = 0. 71073A ,μ= 13. 799cm-1,F(000) = 2408. Final R=0. 067 for 4000 reflections. The structure consists of the neutral cluster molecule [Mo3S4(μ-OAc) (dtp)3(py)] (dtp = [S2P(OEt)2]) and the solvent ethyl acetate (AcOEt). The three Mo-Mo bond lengths in the title compound are 2. 691(2) ,2. 747(2) ,2. 762(2) A ,whereas the Mo-N bond length in Mo(3) position is 2. 36(2)A. The important bond lengths of these Mo clusters with (py) ring at the loose coordination site are listed for comparison.     

白光LED用荧光材料Ba3 Gd( BO3 )3:Eu3+的发光性能研究

用高温固相反应法制备了稀土离子Eu3+ 掺杂的三元稀土硼酸盐Ba3Gd(BO3)3发光材料, 通过X射线衍射 (XRD) 、荧光光谱和扫描电镜 (SEM) 等测试手段对Ba3Gd(BO3)3:Eu3+ 荧光粉的制备条件、发光性能以及形貌进行了研究. XRD结果表明, 在1000 ℃时可得到Ba3Gd(BO3)3 纯相. 扫描电镜照片显示颗粒基本为球形, 粒径约为200～400 nm. 发光光谱测试表明, Ba3Gd(BO3)3:Eu3+荧光粉在近紫外区(UV) (396 nm)和蓝光区(466 nm)可以被有效地激发, 分别用255和396 nm的紫外光激发样品时, 以Eu3+ 的 5D0-7F2 (611和616 nm) 超灵敏跃迁为主要发射峰. 当Eu3+的掺杂浓度为10%(摩尔分数)时, Ba3Gd(BO3)3:Eu3+ 在611和616 nm处的发光强度最大. 因此, 这种荧光粉是一种可能应用在白光LED上的红色荧光材料.     

SYNTHESIS AND STRUCTURAL CHARACTERIZATION OF IN-COMPLETE CUBANE CLUSTER C(MoCu_3S_3) (O)(μ-dtp)(PPh_3)_3]

<正> A new mixed-metal sulfido incomplete cubane cluster [(MoCuS3) (O) (μ-dtp) (PPh3)3] Cdtp = S2P (OC2H5)2] has been prepared by reaction of (NH4)2MoOS3 with Cu(dtp) (PPh3)2 in dimethylformamide solution. It crystallizes in the triclinic space group P1, a = 13.810(5), b = 19. 753(5), c=11. 719(4) A. α=99. 42(2), β=107. 24(3),γ=88. 05(3)°, V = 3012(2)A3, Dc = l. 51g/cm3and Z = 2. Final R=0. 046, Rw = 0. 056 for 7700 unique intensity data(I≥3σ(I)). The central unit [MoCu3S3]3+ can be described as a distorted incomplete cube with one missing corner. The Mo atom is tetrahedrally coordinated by three μ3-S atoms and one terminal O atom. Two Cu atoms are tetrahedrally coordinated whereas the third Cu atom has a highly distorted trigonal environment. The mean Mo - Cu bond length is 2. 752A. The Cu...Cu distances are in the range of 3. 200(1) -3. 740(1) A which are too long to form bonds.     

簇合物〔WOS_3 Ag_3 Br(PPh_3)_3〕·(OPPh_3)的合成和晶体结构

报道了〔WOS3Ag3Br(PPh3) 3〕·(OPPh3)簇合物 (C72 H6 0 Ag3BrO2 S3P4W ,Mr=176 4.6 1)单晶的合成和结构。该晶体属于三方晶系 ,空间群为R3 ,晶胞参数 :a =16 .14 0 (3) ,c =2 3 .0 0 3(4) ,V =5 189.4(15 ) 3,μ(MoKα) =3 .2 98mm- 1 ,Z =3 ,F(0 0 0 ) =2 5 98,Dc=1.6 94g/cm3。独立衍射点 2 181,可观察衍射点 195 2 (I≥ 2σ(I) ) ,R =0 .0 496 ,wR =0 .12 48。该晶体由簇合物分子〔WOS3Ag3Br(PPh3) 3〕和以P为中心的扭曲四面体结构的中性分子OPPh3 构成 ,其中的簇合物分子的骨架为由1个W原子、3个S原子、3个Ag原子和 1个Br原子构成的立方烷状。W、O(1)和Br原子位于C3轴上。     

CRYSTAL AND MOLECULAR STRUCTURE OF β-(Et_4N)_3 [Fe_3(SPh)_3Br_3C1_3]

<正> Introduction. Previously, we have reported the compound α-(Et_4N)_3[Fe_3(SPh)_3-Br_3Cl_3](Ⅰ)~1 with C_2 symmetry. An isomer(Ⅱ) of this compound, which has D_3dsymmetry, is reported in this paper. Brow-green crystals of Ⅱ is obtained from the reaction of FeCl_2, PhSNa and Et_4NBr (1:1:1) in acetonitrile solution.     

SYNTHESIS AND CRYSTAL STRUCTURE OF COMPLEX [CrMo_3 (μ_3-O)_3(μ-O)(μ-O_2CCH_3)_5(O_2CCH_3)_3]Na2 · H_2O

<正> The title complex C CrMo3 (μ3-O )3 (μ-O) (μ-O2CCH3 )5 (O2CCH3)3]2Na2 · H2O (Mr=1814. 32) crystallizes in monoclinic, space group P21/ n with a=11.209(5), b=18. 05(1), c=14. 44(1) A , β= 98. 30(5)°. V=2890 (3) A3, Z=2, A = 2. 08 g/cm3, F(000) -1780, Final R = 0. 049, Rw = 0. 058 for 2622 independent reflectons with I>3σ(I). The complex anion contains two Mo3O4 cores which connect two chromium atoms through four μ3-O atoms and eight bridging CH3COO- groups. Each of the Cr atoms and the Mo atoms is coordinated by six oxygen atoms. The anions are linked by Na cations to form one-dimensional infinite chain structure.     

TRINUCLEAR BASIC CARBOXYLATE COMPOUNDS OF TRANSITION METALS PART 2. SYNTHESIS AND CRYSTAL STRUCTURE OF [Fe_3O (EtCO_2)_3(MeCO_2)_3(H_2O)_3]NO3·H_2O

<正> The title complex crystallizes in monoclinic system,space group C 2/m with α=19. 870(5),b=13. 070(2),c=18. 246(4)A ,β=134. 32(1)°,Mr = 707. 88, V=3390. 0A3.Z = 4,DC=1. 387g/cm3,F(000) = 1468,final R=0. 066 for 2244 independent reflections with Ⅰ >3σ(Ⅰ). The cation was shown to contain three Fe (Ⅲ) atoms at the apices of an equilateral triangle with a 3-O bridge.The Fe (1)-(μ3-O)and Fe(2)-(μ3-O) distances are 1. 907(6) and 1. 87(1) A , respectively. And mixed ligands of acetato and propionyloxy lato are bridged to each pair of the Fe(Ⅲ) atoms.     

SYNTHESIS AND CRYSTAL STRUCTURE OF [(PPh_3)_3(Cu_3S_3MoBr)O]-0. 5CH_2C1_2

<正> [(Ph3P)3 (Cu3S3MoBr)O] 0. 5CH2C12, Mr = 1308. 00, monoclinic, P21/c,a=11. 831(3),b = 28. 471(8),c=19. 232(5) A ,β= 101. 05(3)°,V = 6358 A3,Z = 4,DC=1.37 g/cm3,F(000) = 2620,μ(MoKa) = 20. 47 cm-1. Final R=0. 085 for 4271 observede reflections. The core [Cu3S3MoBr] has a distorted cubic configuration. Two dichloromethane molecules distribute statistically in a unit cell.     

SYNTHESIS AND STRUCTURE OF[Et_4N]_3[FE_3(SPh)_3Br_3Cl_3]

<正> The title compound was synthesized and its structure solved. The formula is [Et4N]3[Fe3(SPh)3Br3Cl3]. M=1231.95, monoclinic, space group C2/c, a=24.569(4), b=13.504(2), c=18.348.(3)A, β=110.78(1)°, V=5691(3)A3, Z=4, Dm= 1.41, Dc=1.44-g/cm3. The flat structure of the anion has. a planar [Fe3S3] ring and three phenyl groups. Statistical distribution of chlorine and bromine atoms on two sides of the [Fe3S3] plane results in a C2 symmetry of the anion.     

新型Cp'Ti(O-C_6H_4-X)_3茂钛催化剂的苯乙烯间规本体聚合研究

对位卤代的苯酚与五甲基茂三氯化钛在三乙胺存在下进行酯化反应 ,制得五甲基茂基三 (对 卤代苯氧基 )钛的 4种新型化合物Cp Ti(O C6 H4 X) 3(X =F ,Cl,Br,I) .用作主催化剂经甲基铝氧烷 (MAO)和三异丁基铝 (TIBA)活化 ,对苯乙烯间规聚合显示出极高的催化活性 ,催化剂热稳定性好 ,制得的聚苯乙烯间规度、分子量和熔点均高 ,在MAO TIBA Ti =4 0 0 2 0 0 1(摩尔比 ) ,温度 6 0℃时 ,10min催化效率可达 3 4 7× 10 6gPS mol·Ti,MAO TIBA Ti=4 0 0 2 0 0 1时茂钛化合物的催化活性几乎是MAO Ti=6 0 0时的 10倍以上 ;4种茂钛催化剂的活性次序Cp Ti(O C6 H4 F) 3 >Cp Ti(O C6 H4 Cl) 3 >Cp Ti(O C6 H4 Br) 3 >Cp Ti(O C6 H4 I) 3 .     

单茂钛催化剂的苯乙烯间规聚合和乙烯聚合的比较

考察三甲基铝（ＴＭＡ） 部分水解法制备固体改性甲基铝氧烷（ｍ ＭＡＯ） 时,反应物Ｈ２Ｏ 和ＴＭＡ 的摩尔比对ｍ ＭＡＯ 的产量及ｍ ＭＡＯ 中ＴＭＡ 含量的影响;以五甲基茂基三苄氧基钛［Ｃｐ ＊ Ｔｉ（ＯＢｚ）３］／ｍ ＭＡＯ 组成的均相催化体系,分别考察ｍ ＭＡＯ 的用量［ 即Ａｌ／Ｔｉ 摩尔比］ 及ｍ ＭＡＯ 中ＴＭＡ 含量对苯乙烯间规聚合和乙烯聚合的影响．通过分析Ｃｐ ＊ Ｔｉ（ＯＢｚ）３／ｍ ＭＡＯ 催化体系钛氧化态的分布,发现Ｔｉ（ Ⅲ） 活性中心有利于合成间规聚苯乙烯;而Ｔｉ（ Ⅳ） 活性中心有利于合成聚乙烯．苯乙烯间规聚合时,外加三异丁基铝（ＴＩＢＡ） ,将提高催化活性,同时可节省ＭＡＯ 用量．     

Triisobutylaluminum as cocatalyst for zirconocenes. I. Sterically opened zirconocene/triisobutylaluminum/perfluorophenylborate as highly effective ternary catalytic system for synthesis of low molecular weight polyethylenes

Ethylene polymerizations with catalytic systems Me₂SiCp*N^tBuZrX₂ ( 1 ) [Cp* = C₅(CH₃)₄; X = Cl ( 1Cl ), Me ( 1Me )], triisobutylaluminum (TIBA), perfluorophenylborate CatB(C₆F₅)₄ [Cat = CPh₃ ( 3 ), Me₂NHPh ( 4 )], or Me₂SiCp₂ZrX₂ [X = Cl ( 2Cl ), Me ( 2Me )]/TIBA/ 3 ( 4 ) were performed within a wide range of ethylene pressures of different Al/Zr ratios, and Zr/B = 1. Catalytic systems 1Cl ( 2Cl )/TIBA/ 3 led to the formation of very high linear molecular weight polyethylene (PE) of M_η ∼2,000,000 with low activity. The replacement of both chlorine ligands in the precatalyst for the methyl ones led to the formation of active species producing low molecular weight PE with high activity. Chain transfer to ethylene was shown to be the main reaction controlling PE chain propagation: k_p/k_tr ∼20–30 for 1Me /TIBA/ 3 and k_p/k_tr ∼350–500 for 2Me /TIBA/ 3 . It was suggested that TIBA was present in the active center first in the form of a neutral heterobimetallic Zr–Al bridged complex followed by the formation of a partially polarized Zr–Al(Cl)R₂ (R = ⁱBu) or an unreactive Zr–AlR₃ cationic complex by abstraction of the alkyl ligand under the action of borate. It was concluded that AlR₃ from the latter cationic complex may be easily reversibly replaced under the specific coordination of ethylene or accumulated α-olefin, giving rise to highly labile and sterically accessible cationic species. Experiments on ethylene polymerization with the catalytic systems 1Cl ( 1Me )/TIBA/ 3 /Ph₂NH, 1Cl ( 1Me )/TIBA/ 4, 2Cl ( 2Me )/TIBA/ 3 /Ph₂NH, and 2Cl ( 2Me )/TIBA/ 4 were performed to confirm the suggestion. Catalytic systems derived from dichloride complexes in the presence of a σ-donor substrate also produced low molecular weight PEs with molecular weight characteristics similar to those of products obtained with the dimethylated precatalysts. The specific feature of active species derived from 2Me complexes to isomerize coordinated α-olefin into trans-vinylene polymer chains was also revealed. The catalytic behavior of the ternary catalytic system based on 2Me relative to 2Me or 2Cl precatalysts activated with polymethylaluminoxane at different Al/Zr ratios was compared. © 2001 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 39: 1901–1914, 2001     

Polymerization of methyl methacrylate with ethylene bridged heterodinuclear metallocene of samarium and titanium

A novel heterodinuclear catalyst, ethylene bridged samarocene and titanocene chloride (Sm-Ti), was used both as a single component catalyst (cat.) and also by activation with triisobutyl aluminum (TIBA) to polymerize methyl methacrylate (MMA). The binary catalyst demonstrated higher activity than the single component, but the molecular weight of the resultant PMMA is lower. Ultrahigh molecular weight PMMA (1.5×10⁶) was obtained at an attractive conversion (87%) without any cocatalyst. The effects of polymerization parameters, such as temperature, time, molar ratios of Al(i-Bu)₃/cat. and MMA/cat., were studied in detail. The results showed that the catalytic activity had a rather different dependence on the polymerization temperature with/without TIBA. High molecular weight PMMA was much more easily prepared in a bulk system than in toluene solution. The polymer yielded with about 65% syndiotacticity by 1H NMR and 75% by IR spectroscopy, but its stereoregularity did not change too much with polymerization temperature and the concentration of TIBA.     

茂钛均相催化剂丁二烯聚合研究

由五甲基单茂钛化合物Cp TiL3 和甲基铝氧烷 (MAO)组成的催化体系进行丁二烯聚合 .考察具有不同辅助配体L的主催化剂Cp TiL3 及外加三异丁基铝 (TIBA)对聚合的选择性 ;讨论了聚合温度、AlMAO Ti摩尔比和催化剂浓度对聚合反应的影响 .发现外加适量TIBA有助于提高催化活性 ,而且随着TIBA用量的增加聚丁二烯分子量增加 .结合钛氧化态分析 ,说明催化体系中Ti(Ⅲ )活性中心更有利于丁二烯聚合     

Syntheses of isobutylalumoxanes by triisobutylaluminum hydrolysis and their use as activators of dimethylated zirconocene in propylene polymerization

Isobutylalumoxanes of different composition were synthesized by the hydrolysis of triisobutylaluminum (TIBA) with crystalline hydrate CuSO₄·5H₂O and water taken as cooled ice or as vapor. The composition of the formed alumoxanes and the degree of water participation in their formation was monitored by ¹H NMR. The hydrolysis of TIBA on CuSO₄·5H₂O is rather selective method of synthesis of alumoxanes. The synthesized alumoxanes were used for the activation of dimethylated zirconocenes rac-Me₂Si(2-Me,4-PhInd)₂ZrMe₂ and rac-Et(2-MeInd)₂ZrMe₂ in propylene polymerization at the molar ratios Al/Zr = 50–750. It was concluded that the hydrolysis afforded several products with different structures and different activating ability. The systems with oligomeric forms of isobutylalumoxanes, especially those obtained by TIBA hydrolysis with water, showed the highest activity.     

表面酸性对Ni/SiO_2-Al_2O_3催化剂催化1,4-丁炔二醇高压加氢性能的影响

通过浸渍法分别在Al(OH)_3和Al_2O_3中引入SiO_2,经焙烧后制备具有不同表面酸性质的SiO_2-Al_2O_3载体,以上述SiO_2-Al_2O_3及Al_2O_3为载体,采用等体积浸渍法制备Ni负载量为15%的Ni/SiO_2-Al_2O_3催化剂(分别为Ni/SA-1和Ni/SA-2)与Ni/Al_2O_3.采用N2物理吸附、Py-FTIR、NH3-TPD、XRD、H2-TPR和H2-TPD手段对催化剂进行表征,考察了表面酸性质对催化剂催化1,4-丁炔二醇高压加氢性能的影响.结果表明,SiO_2引入方式会影响Ni/Al_2O_3催化剂表面酸性质及活性组分Ni在载体表面的分散行为.在Al(OH)3中引入SiO_2时,Ni/SA-1催化剂不仅活性组分具有高分散度,而且表面具有丰富的L酸位点,L酸位点与Ni活性中心协同作用有效提高了催化剂的高压加氢性能.而在Al_2O_3中直接引入SiO_2时,SiO_2覆盖了Al_2O_3表面的L酸位点,催化剂活性组分分散度较低,表现出低的加氢活性.     

茂钛催化剂聚1-丁烯的合成

茂金属催化烯烃聚合以其高活性、定向性等特点受到广泛重视.Ｋａｍｉｎｓｋｙ[1～4]等用二茂基(Ｃｐ、Ｉｎｄ和Ｆｌｕ)过渡金属(Ｔｉ、Ｚｒ和Ｈｆ)化合物/ＭＡＯ催化剂催化1丁烯聚合,可得到间规(ｓＰＢ)、无规(ａＰＢ)或等规(ｉＰＢ)聚1丁烯.Ｌｉｎ[5]和Ｗｕ[6]分别用单茂基的ＣｐＴｉ(ＯＰｒ)3/ＭＡＯ和ＣｐＴｉ(ＯＢｚ)3/ＭＡＯ催化剂进行丙烯聚合,都得到无规聚丙烯(ａＰＰ),并研究了催化体系中Ｔｉ氧化态分布,认为Ｔｉ+4有利于α烯烃聚合.有关用单茂钛化合物/ＭＡＯ催化体系催化1丁烯聚合的研究目前较少文献报道.本文用新型茂钛催化剂—…     

Effect of Al2O3 Binder on the Precipitated Iron-Based Catalysts for Fischer-Tropsch Synthesis

A series of iron-based Fischer-Tropsch synthesis (FTS) catalysts incorporated with Al2O3 binder were prepared by the combination of co-precipitation and spray drying technology. The catalyst samples were characterized by using N2 physical adsorption, temperature-programmed reduc-tion/desorption (TPR/TPD) and Mossbauer effect spectroscopy (MES) methods. The characterization results indicated that the BET surface area increases with increasing Al2O3 content and passes through a maximum at the Al2O3/Fe ratio of 10/100 (weight basis). After the point, it decreases with further increase in Al2O3 content. The incorporation of AI2O3 binder was found to weaken the surface basicity and suppress the reduction and carburization of iron-based catalysts probably due to the strong K-Al2O3 and Fe-Al2O3 interactions. Furthermore, the H2 adsorption ability of the catalysts is enhanced with increasing Al2O3 content. The FTS performances of the catalysts were tested in a slurry-phase continuously stirred tank reactor (CSTR) under the reaction conditions of 260℃, 1.5 MPa, 1000 h-1 and molar ratio of H2/CO 0.67 for 200 h. The results showed that the addition of small amounts of Al2O3 affects the activity of iron-based catalysts to a little extent. However, with further increase of Al2O3 content, the FTS activity and water gas shift reaction (WGS) activity are decreased severely. The addition of appropriate Al2O3 do not affect the product selectivity, but the catalysts incorporated with large amounts of Al2O3 have higher selectivity for light hydrocarbons and lower selectivity for heavy hydrocarbons.     

Theoretical exploration of hydrogen loss from Al3H9

The Al(3)H(9) and Al(3)H(7) potential energy surfaces were explored using quantum chemistry calculations to investigate the H(2) loss mechanism from Al(3)H(9), which provide new insights into hydrogen production from bulk alane, [AlH(3)](x), a possible energy storage material. We present results of B3LYP/6-311++G(d,p) calculations for the various Al(3)H(9) and Al(3)H(7) optimized local minima and transition state structures along with some reaction pathways for their interconversion. We find the energy for Al(3)H(9) decomposition into Al(2)H(6) and AlH(3) is slightly lower than that for H(2) loss and Al(3)H(7) formation, but the calculations show that H(2) loss from Al(3)H(9) is a lower energy process than for losing hydrogen from either Al(2)H(6) or AlH(3). We found four transition state structures and reaction pathways for Al(3)H(9) → Al(3)H(7) + H(2), where the lowest energy activation barrier is around 25-73 kJ/mol greater than the experimental value for H(2) loss from bulk alane. Intrinsic reaction coordinate calculations show that the H(2) loss pathway involves considerable rearrangement of the H atom positions around a single Al center. Three of the pathways start with the formation of an AlH(3) moiety, which then enables a terminal H on the AlH(3) to get within 1.1 to 1.2 ? of a nearby bridging H atom. The bridging and terminal H atoms eventually combine to form H(2) and leave Al(3)H(9). One implication of these H(2) loss reaction pathways is that, since the H atoms in bulk alanes are all at bridging positions, if a similar H(2) loss mechanism were to apply to bulk alane, then H(2) loss would most likely occur on the bulk alane surface or at a defect site where there should be more terminal H atoms available for reaction with nearby bridging H atoms.