甲基对硫磷-D6的合成

报道了一种合成甲基对硫磷-D₆的新方法。以三氯硫磷、氘代甲醇和对硝基苯酚为起始原料,经三次酯化反应合成了目标产物甲基对硫磷-D₆,总收率47.6%,其结构经¹H NMR、 ¹³C NMR、 ³¹P NMR和HR-MS(ESI)确证。     

一维链状有机锡配合物[Ph3Sn(OCOC5H4NO)]n的合成和晶体结构

有要锡配合物因基具有很强的生物活性以及多变的结构而日益受到人们的关注[1～4].有关该化合物的结构研究表明,中心锡原子的配位形式决定于直接与锡原子相连接的烃基的结构和羧酸基配体的类型[5～7].为了进一步探索有机锡羧配合物的结构类型、羧酸配体中带额外孤电子对的杂原子与锡原子的作用方式,本文合成了一个有机锡羧酸配合物[Ph3Sn(OCOC5H4NO)]n,并用X-射线衍射单晶结构分析方法测定了它的晶体结构.     

稳定同位素标记15N-N,N-二甲基苯胺的合成

以15NH4Cl为同位素标记前体,经与苯甲酰氯胺化、霍夫曼降解得到15N标记苯胺,15N标记苯胺再与对甲苯磺酸酯进行甲基化反应,合成得到一种重要的同位素标记基础试剂15N-N,N-二甲基苯胺.以消耗的15NH4Cl计,三步反应总收率大于58.3%.产品结构经红外(IR)、核磁(NMR)、高效液相(HPLC)、质谱(MS)等表征进行确定,其化学纯度大于99.0%,同位素丰度大于98.4%15N.     

Ru-Ni/Al2O3催化马来酸二甲酯加氢性能研究

以Al₂O₃为载体,RuCl₃·xH₂O及Ni（NO₃）₂·6H₂O为活性组分前驱体,采用吸附-沉淀法制备系列Ru-Ni/Al₂O₃催化剂,以马来酸二甲酯（DMS）催化加氢为探针反应,考察了活化条件和Ni的添加量对催化剂性能的影响。随Ni负载量的升高,Ru-Ni/Al₂O₃催化剂活性呈现先升高后降低的趋势,在Ni：Ru的原子比为6：1时（催化剂Ru₁Ni₆/Al）催化活性最高。催化剂Ru₁Ni₆/Al在氢气中200 ℃直接还原后的平均转化率与氢气中400 ℃还原后的平均转化率接近,达到了单组分Ru/Al催化剂的1.5倍以上。XPS、XRD、H₂-TPR数据表明,Ru与Ni之间发生了较强的相互作用,Ni的加入促进了金属Ru在载体上的分散,提高了催化活性。     

MoO3/Al2O3催化氧化选择性合成亚砜

采用浸渍法制备了不同负载量的MoO3/Al2O3催化剂,讨论了MoO3,Al2O3和MoO3/Al2O3负载的催化剂作用下,利用H2O2进行硫醚氧化制亚砜的反应.结果显示MoO3/Al2O3催化剂负载量为20%时催化活性最高,原料转化率达100%,且没有副产物生成.将该方法应用到兰索拉唑前体的氧化反应中,收率达到80%.催化剂重复使用6次不失活.     

3-三氟-2-羟基/氨基-1-氟代丙基膦酸酯的合成

Reaction of diethyl 2,2-difluoro-3-（a-methylbenzyl）imino-4,4,4-trifluoropropanephosphonate （3） with triethylamine afforded a mixture of normal [1,3]-proton shift reaction product 5 and its HF-eliminated compound 6Z in 1 ： 1 ratio. Upon hydrolysis, this reaction mixture gave solely 1,3,3,3-tetrafluoro-2-dioxypropanephosphonate （9）. Reaction of 3 with DBU provided only 6, in which the ratio of E/Z forms was dependent on the reaction conditions. Aqueous hydrolysis of 6 led to 9. Catalytic hydrogenation and hydrogenolysis of 6 gave geometric isomers of 11 as expected. The reaction mechanism involved was discussed.     

同位素示踪研究K2CO3/CH3I促进的碳酸二甲酯直接合成反应

 采用同位素示踪技术,系统地研究了K2CO3/CH3I促进的CO2插入甲醇直接合成碳酸二甲酯(DMC)的反应机理. 结果表明,固体碱碳酸钾催化剂直接参与了DMC的合成过程, DMC分子中的羰基由CO2插入甲醇后形成,两个甲基分别来源于甲醇和碘甲烷. 本文将以往文献中提出的DMC生成机理和二甲醚生成机理结合起来,并对其进行适当补充后,可以很好地解释实验结果.     

5-三氟甲基胡椒醛的合成研究

以香草醛为起始原料,经碘代、脱甲基、亚甲基醚化、三氟甲基化反应以较高收率合成了5-三氟甲基胡椒醛,产物结构经过了1H NMR,13C NMR,19F NMR和HRMS的确证.重点研究了三氟甲基化反应,考察了不同三氟甲基化试剂、溶剂、催化剂用量、反应温度以及反应时间对三氟甲基化反应收率的影响,确定了最佳反应条件.随后,该方法成功运用于3,4位不同取代的5-碘苯甲醛的三氟甲基化反应,制得了三种5-三氟甲基胡椒醛的衍生物.     

Sb2O3/BiVO4/WO3异质结构建及光电催化合成过氧化氢

采用溶剂热法-旋涂法构建了Sb₂O₃/BiVO₄/WO₃半导体异质结,并采用X射线衍射、扫描电子显微镜、X射线光电子能谱等手段表征了其物化性质。在1.23 V(vs RHE)电位下,BiVO₄/WO₃的光电流密度相对于BiVO₄提高了2倍。进一步复合Sb₂O₃之后,虽然Sb₂O₃/BiVO₄/WO₃薄膜的光电流密度有所下降,但其光电催化产H₂O₂的法拉第效率和产生速率得到明显提升。在1.89V(vs RHE)电位下,3c-Sb₂O₃/BiVO₄/WO₃薄膜产H₂O₂的法拉第效率提高到约19%;1c-Sb₂O     

一种新型多孔道配位聚合物[La(C8H6NO2)3]n的合成及晶体结构表征

A novel porous coordination polymer [La(C₈H₆NO₂)₃]_n was synthesized by hydrothermal reaction of flexible ligands 3-(3-pyridyl)acrylate and La(NO₃)₃·6H₂O. The structure was characterized by elemental analysis， IR spectroscopy and X-ray single crystal diffraction. X-ray single crystal analysis reveals the structure consists of [La(C₈H₆NO₂)₃]_n. It crystallizes in monoclinic crystal system with space group P2(1)/c. Crystallographic date: a=0. 7889(3)nm， b=2.5916(9)nm， c=1.1489(4)nm， α=90.00°， β=95.219(6)°， γ=90.00°， V=2.3393(15)nm³， Z=4， D_c=1.656g·cm^-3， μ=1.871mm^-1， F(000)=1152， R₁=0.0328， wR₂=0.0522. CCDC: 211700.     

Synthesis and crystal chemistry of NH3(MoO3)3

NH₃(MoO₃)₃ crystallizes with hexagonal symmetry, space group $\text{P6}{}_3\text{m}$, lattice constants a = 10.568 Å, c = 3.726 Å, and Z = 2. The crystal structure has been determined by Patterson synthesis and refined assuming isotropic temperature factors to a final conventional R value of 0.085. The structure shows a three-dimensional arrangement built up of double chains of distorted MoO₆ octahedra, parallel to the [001] direction. The octahedral double chains are linked among each other through common oxygen atoms. In addition to the shared oxygen atoms, each molybdenum is coordinated to one terminal oxygen. MoO distances range from 1.645 to 2.378 Å and OMoO angles from 74.3 to 114.3°. These results are consistent with the fact that molybdenum in high-valence states shows octahedral coordination with terminal oxygens.     

Synthesis of Cr2(MoO4)3

Studies on the kinetics and mechanism of the reaction leading to Cr₂(MoO₄)₃ have been made using X-ray diffraction and infrared spectroscopy. The apparent activation energy, E=285±22 kJ/mol has been calculated, based on the Ginstling-Brounstein diffusion controlled model.     

超细YF_3与GdF_3纳米晶的合成及其上转换发光

当使用液固溶法(LSS法)制备分散性纳米晶时,将传统油酸/油酸钠/酒精反应体系中的NaOH用氨水取代时,氨水将会与油酸形成新的表面活性剂油酸铵,这样就可以合成各种超细分散性的REF3纳米晶(RE代表稀土元素)。在这种新的反应体系中,合成了平均直径小于10 nm的YF3和GdF3超细颗粒,X射线与透射电镜测试表明YF3是正交相,而GdF3是面心立方结构,空间群为Fm3m,晶格常数为0.582 9 nm。在980 nm半导体激光器激发下,可检测到YF3∶Yb/Er在515~570 nm处有较强的绿色发光峰、645~675 nm处有较强的红色发光峰,呈橙色发光。YF3∶Yb/Tm和GdF3∶Yb/Tm样品在460~490 nm处有较强的蓝色发光峰,而在800 nm附近有更强的近红外发光峰。由于其超细的尺寸及红外上转换发光特性,合成的样品在生物成像、生物标签等方面有潜在的应用价值。     

Synthesis of gibberellins A8 and A56 from gibberellin A3

A mixture of gibberellin A₃ derivatives with 1(10)-ene-2,3-diol and 1(10)-ene-2,3-diol (2:5) groups, readily obtained from gibberellin A₃, has been used for a new and simple synthesis of gibberellin A₈ and its esters. The hydrolysis of GA₃ and the iodolactonization of a mixture of the 2-epimers was carried out in aqueous solution in a single flask, as also was a synthesis of GA₅₆ from GA₃ by a method that we have modified. The mixture of 1-iodides of GA₈ and GA₅₆ was separated by chromatography on SiO₂ in the form of methyl or p-bromophenacyl esters which were then deiodinated and the methyl or p-bromphenacyl ester of GA₈ was isolated. Free GA₈ was obtained by the dephenylation of the latter ester. By two-dimensional NMR spectroscopy we succeeded in assigning all the signals in the¹³C and¹H NMR spectra of the methyl esters of GA₈ and GA₅₆. In an attempt to obtain GA₅ methyl ester by the action of trimethylchlorosilane/sodium iodide on the 2,3-diol system in GA₅₆ methyl ester, the 8,13-epimer of the latter was formed, the structure of its molecule being established from the results of X-ray structural analysis.Novosibirsk Institute of Organic Chemistry, Siberian Division of the Russian Academy of Sciences. Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 663–669, September–October, 1994.     

Synthesis, crystal structures and photoluminescence properties of new oxyborates, Mg5NbO3(BO3)3 and Mg5TaO3(BO3)3, with novel warwickite-type superstructures

Single crystals of new oxyborates, Mg₅NbO₃(BO₃)₃ and Mg₅TaO₃(BO₃)₃, were prepared at 1370 °C in air using B₂O₃ as a flux. They were colorless and transparent with block shapes. X-ray diffraction analysis of the single crystals revealed Mg₅NbO₃(BO₃)₃ and Mg₅TaO₃(BO₃)₃ to be isostructural. The X-ray diffraction reflections were indexed to the orthorhombic Pnma (No. 62) system with a=9.3682(3) Å, b=9.4344(2) Å, c=9.3379(3) Å and Z=4 for Mg₅NbO₃(BO₃)₃ and a=9.3702(3) Å, b=9.4415(3) Å, c=9.3301(2) Å and Z=4 for Mg₅TaO₃(BO₃)₃. The crystal structures of Mg₅NbO₃(BO₃)₃ and Mg₅TaO₃(BO₃)₃ are novel warwickite-type superstructures having ordered arrangements of Mg and Nb/Ta atoms. Polycrystals of Mg₅NbO₃(BO₃)₃ prepared by solid state reaction at 1200 °C in air showed broad blue-to-green emission with a peak wavelength of 470 nm under 270 nm ultraviolet excitation at room temperature.     

超细YF3与GdF3纳米晶的合成及其上转换发光

当使用液固溶法（LSS法）制备分散性纳米晶时,将传统油酸/油酸钠/酒精反应体系中的NaOH用氨水取代时,氨水将会与油酸形成新的表面活性剂油酸铵,这样就可以合成各种超细分散性的REF₃纳米晶（RE代表稀土元素）。在这种新的反应体系中,合成了平均直径小于10nm的YF₃和GdF₃超细颗粒,X射线与透射电镜测试表明YF₃是正交相,而GdF₃是面心立方结构,空间群为Fm3m,晶格常数为0.5829nm。在980nm半导体激光器激发下,可检测到YF₃：Yb/Er在515~570nm处有较强的绿色发光峰、645~675nm处有较强的红色发光峰,呈橙色发光。YF：Yb/Tm和GdF₃：Yb/Tm样品在460~490nm处有较强的蓝色发光峰,而在800nm附近有更强的近红外发光峰。由于其超细的尺寸及红外上转换发光特性,合成的样品在生物成像,生物标签等方面有潜在的应用价值。     

Synthesis and characterization of Fe2O3/SiO2 nanocomposites

Fe₂O₃/SiO₂ nanocomposites based on fumed silica A-300 (S_BET = 337 m²/g) with iron oxide deposits at different content were synthesized using Fe(III) acetylacetonate (Fe(acac)₃) dissolved in isopropyl alcohol or carbon tetrachloride for impregnation of the nanosilica powder at different amounts of Fe(acac)₃ then oxidized in air at 400–900 °C. Samples with Fe(acac)₃ adsorbed onto nanosilica and samples with Fe₂O₃/SiO₂ including 6–17 wt% of Fe₂O₃ were investigated using XRD, XPS, TG/DTA, TPD MS, FTIR, AFM, nitrogen adsorption, Mössbauer spectroscopy, and quantum chemistry methods. The structural characteristics and phase composition of Fe₂O₃ deposits depend on reaction conditions, solvent type, content of grafted iron oxide, and post-reaction treatments. The iron oxide deposits on A-300 (impregnated by the Fe(acac)₃ solution in isopropanol) treated at 500–600 °C include several phases characterized by different nanoparticle size distributions; however, in the case of impregnation of A-300 by the Fe(acac)₃ solution in carbon tetrachloride only α-Fe₂O₃ phase is formed in addition to amorphous Fe₂O₃. The Fe₂O₃/SiO₂ materials remain loose (similar to the A-300 matrix) at the bulk density of 0.12–0.15 g/cm³ and S_BET = 265–310 m²/g.     

Synthesis of morphology-controllable mesoporous Co3O4 and CeO2

Recently, extensive works have been devoted to the morphology control of mesoporous materials with respect to their use in various applications. In this paper, we used two kinds of mesoporous silica, SBA-15 rods and spheres as hard templates to synthesize morphology-controllable mesoporous metal oxides. By carefully controlling the loading of metal precursors in the mesopores of the hard template, mesoporous Co₃O₄ and CeO₂ with different morphologies, such as micrometer-sized rod, hollow sphere, saucer-like sphere, and solid sphere were conveniently obtained. The structural properties of these materials were characterized by XRD, BET, SEM and TEM. In addition, it is found that the differences observed in the textural properties of the two mesoporous metal oxides nanocasted from the same template can be attributed to the properties of metal precursors and the interaction between metal oxide and SiO₂. Thus-obtained mesoporous metal oxides with such special morphologies may have a potential application in the field of environmental catalytic oxidation.