Catalytic epoxidation of olefin over supramolecular compounds of molybdenum oxide clusters and a copper complex

The catalytic epoxidation of olefin was investigated on two copper complex-modified molybdenum oxides with a 3D supramolecular structure, [Cu（bipy）]4[Mo15O47].2H2O （1） and [Cu1（bix）][（Cu1bix） （δ-MoVl8O26）0.5] （2） （bipy = 4,4＇-bipyridine, bix = 1,4-bis（imidazole-1-ylmethyl）benzene）. Both compounds were catalytically active and stable for the epoxidation of cyclooctene, 1-octene, and styrene with tert-butyl hydroperoxide （t-BuOOH） as oxidant. The excellent catalytic performance was attributed to the presence of stable coordination bonds between the molybdenum oxide and copper complex, which resulted in the formation of easily accessible Mo species with high electropositivity. In addition, the copper complex also acted as an active site for the activation of t-BuOOH, thus im- proving these copper complex-modified polyoxometalates.

Mid-Temperature Synthesis of CeO_2-TiO_2 Complex Compound and Its XRD Structure Study

The CeTi 2O 6, which is formed above 1300 ℃ by ceramic method, was obtained at 700 ℃ using sol gel synthesis method. XRD analysis shows that there is 8% deficient of Ce in the structure. The chemical formula is Ce 0.92 Ti 2O 5.84 , which has a monoclinic structure with space group of C 2/ m . Its cell parameters are a =0.9811(8) nm, b =0.3726(3) nm, c =0.6831(6) nm, and β =118.84°. After being treated at 1300 ℃ for 3 h, the system keeps stable but the deficient disappears, while the chemical formula change to the normal CeTi 2O 6, and the cell parameters are a =0.9813(3) nm, b =0.3752(4) nm, c =0.6883(5) nm, β =119.05°. The key to synthesis the precursors of CeTi 2O 6 is that Ti 4+ and Ce 3+ ions must reach the atomistic distributing state and prevent the oxidation of Ce 3+ during sol gel process.

THE FORMABILITY OF COMPLEX FLOURIDE COMPOUNDS

The formability of complex flourides has been studied by chemical bond parameter-pattern recognition method. In a multi-dimensional space spanned by ionic radius, ionic polarizability, electronegativity and ionic charge of the metal elements, the binary complex flouride-forming systems and binary flouride systems without complex flouride formation distribute in different regions with a clear-cut boundary. The mathematical models obtained are useful for new complex flouride predicton.

Crystal Structure of the Addition Compound of N,N′-Bi(2-pyridylmethyl)-Oxamide and the Complex of Copper with 1,10-Phenanthroline

The structure of addition compound Cu(phen)3(PMoxdH)(CO4)2 was establish ed by means of X-ray crystallography,where PMoxdH is N,N-Bi(2-pyridyl-methyl)-oxamide,in which six nitrogen atoms of the three 1,10,-phen-anthroline bind to the copper ion and the oxygen atom of PMoxdH is uncoordinated.

Examination of Polymeric Azomethine Compounds and Their Transition Metal Complexes by Using XRF and XRD Technique

In this study,the electronic transition properties and structural analysis of the metal complexes(Ni(Ⅱ),Co(Ⅱ),Cu(Ⅱ)and Mn(Ⅱ))of three different polymer ligands were performed by using XRF and X-ray diffraction(XRD)techniques,respectively.The structural analysis of the polymers and their complexes were performed by XRD technique and some of the polymers were found to be in the face-centred cubic(fcc)structure.In addition,the values of the present K X-ray intensity ratios are significantly greater than the values reported in literature.

Structure Studies on New Types of Macrocyclic Compounds Part V．Crystal Structure of Nickel（II） Complex of 5，12－Diphenyl－7，14－dimethyl－1，4，8，11－tetraazacyclotetradecane－N＇，N－diacetic Acid

Crystal structure of nickel（II） complex with a new 14 membered tetraazamacrocyclic ligand 5,12-diphenyl-7,14-dimethyl-1,4,8,11-tetraazacyclotetradecane-N’,N-diacetic acid,Ni[N4C10（CH2COO）2（C6H5）2]·2H2O, Mr= 589. 38 is reported.It crystallizes in monoclinic P21/c space group with a=12.949（6）,b=16.373（3）,c=14.232（16）,β=98.68（6）°,V=2982.9（7）,Z=4,Dc=1.312 gcm-3,μ=6.953 cm-1,F（000）=1256.0.Finally,the structure was refined to R=0.080,Rw=0.065 for 2952 reflections.The central nickel ion of the complex forms an octahedron with four nitrogen atoms of the macrocycle and two oxygen atoms of the appended carboxylate groups.Two phenyl planes of the ligand are almost parallel to each other.

Preparation for Supramolecular Complexes of Chiral Diols BDPDD, DMBDPD and BINOL with Some Prochiral Compounds

Interaction between chiral diols BDPDD, DMBDPD and BINOL with prochiral compounds was examined and some new supramolecular complexes were prepared. It was found that these chiral hosts could include prochiral guests, a, b-unsaturated compounds or piper- azinedione derivatives to give inclusion crystals in different molar ratio. Formations of these supramolecular complexes were characterized by the data of IR and 1H NMR spectra.

Preparation and Characterization of Layered Compound Zirconium Bis(monohydrogenphosphate) Intercalated with Rare Earth Complex

Layered compound zirconium bis(monohydrogenphosphate)(alpha-ZrP) intercalated with rare earth complex Eu(DBM)(3)phen was prepared. The pre-intercalation of p-methoxyaniline into alpha-ZrP makes the interlayer separation large enough to exchange PMA with europium complex, thus, the luminescent assembly was prepared. This was confirmed by X-ray diffraction, UV-visible spectra and elemental analysis. The fluorescence spectra and lifetime of the assembly were also presented.

CHARACTERIZATION OF SOME SCHIFF BASES OF HETEROCYCLIC COMPOUNDS AND THEIR TRANSITION METAL COMPLEXES

Some new Schiff bases were synthesized by the condensation of equimolar quantities of salicylaldehyde and 2-amino-5-phenylazo-pyridine or its derivatives in dry benzene(1):Metal complexes of the type ML_2and M'L_3 where M=Cu^(2+),Co^(2+),Ni^(2+),Mn^(2+)Pd^(2+),M'=Fe^(3+)and L=different newly synthesized monobasic Schiff bases were prepared in absolute ethanolic medium(2)and characterized by elementary analysis,conductance measurements,infrared spectra,electronic spectra,magnetic moments studies.

轮足复合式爬壁机器人研究综述

当前轮足复合式机器人机构主要包含轮足结合、分离复合以及变形轮足,分别能够实现不同障碍通道的移动作业、复杂未知环境的探索操作以及突发应急救援等应用。然而,针对船舶、压力储罐等金属立面环境,轮足复合式爬壁机器人必须兼具壁面适应、越障和壁面过渡的全位置自主作业能力,应用于壁面焊接、清洗、检测等作业任务。对比分析当前的国内外研究,轮足复合式爬壁机器人针对在垂直和倾斜壁面的工程应用有良好的适用性,它具备适应复杂曲面工作面的能力,并能够应对非结构化工作场景。轮足复合式爬壁结构在应对曲率变化、非结构化壁面等工作将会有良好的应用前景。

英语with复合结构赏析助力思辨性读写探索

作为英语中常见的一类复合结构,with结构聚合多重信息,体现英语长难句的特征。具有包容性、能动性和体验性的思辨性读写能力提升离不开对with复合结构的识别、推敲、加工和赏析。文中用具体实例分析with复合结构在表达复杂内容、传递多层含义等传情达意方面的独特功能,并且阐释英语with复合结构赏析助力思辨性读写的逻辑关系。为了能够精准地思辨性理解英语长难句,学习者需要捕捉英语语言微妙之处,品味语言魅力,养成语言输出时使用with复合结构的习惯,实现英语读写彼此促进、相得益彰。

Syntheses, Characterization and Biological Activity of Coordination Compounds of 3-Hydroxy-2-methyl-4<i>H</i>-pyran-4-one and Its Mixed Ligand Complexes with 1,2-Diaminocyclohexane

Coordination compounds of 3-hydroxy-2-methyl-4H-pyran-4-one with iron(III), cobat(III) and chromium(III) were synthesized with M:L (1:2). Mixed ligand coordination compounds of 3-hydroxy-2-methyl-4H-pyran-4-one and 1,2-diaminocyclohexane using the same metal ions were also synthesized M:L1:L2 (1:1:1) where L1 is 3-hydroxy-2-methyl-4H-pyran-4-one and L2 is 1,2-diaminocyclohexane. The coordination compounds obtained were characterized using electronic and infrared spectral analyses, magnetic susceptibility and percentage metal analysis. They were also evaluated for their cytotoxic and antioxidant activities. The result obtained suggested that octahedral geometry was obtained for all the compounds, as a result of additional two molecules of the solvent coordinated to the metal ions. Both the primary and secondary ligands coordinated in a bidentate fashion. The synthesized compounds exhibited moderate cytotoxicity, although none was as active as the standard. The cobalt(III) mixed ligand complex elicited the highest activity. The synthesized compounds all exhibited good to moderate antioxidant activity.

Syntheses of Coordination Compounds of 2-Amino-3-Methylbutanoic Acid Their Mixed Ligand Complexes and Antibacterial Activities

Coordination compounds of 2-amino-3-methylbutanoic acid were synthesized with chromium(III) and oxovanadium(IV) ions. M:L;1:2. Adducts of these complexes using 1,10-phenantroline and ethylenediamine were further synthesized, M:L, (1:2). These compounds were characterized using electronic, infra-red spectrophotometry, magnetic susceptibility measurement and percentage metal analyses. The zones of inhibition and minimum inhibitory concentrations of the compounds against eight microbes were studied. The results obtained indicated an octahedral geometry for the Cr(III) complexes, indicative of additional coordination of two water molecules. On the other hand a square pyramid geometry was obtained for the binary oxovanadium complex and its 1,10-phenantroline adduct. However, for the oxovanadium ethylenediamine adduct a distorted octahedral geometry was proposed. The result for the antibacterial studies indicated that both mixed ligand complexes of 1,10-phenantroline exhibited good antibacterial activity, and in some cases better activity than the standard, streptomycin.

络合沉淀法—硫化沉淀法联合处理铜氰贫液试验研究

针对某黄金生产企业产生的铜氰贫液,采用络合沉淀法—硫化沉淀法联合进行回收处理。在络合沉淀法五水合硫酸铜投加量3.0 g/L、焦亚硫酸钠投加量2.0 g/L,硫化沉淀法九水合硫化钠加药量0.35 g/L条件下,铜氰贫液中总氰化合物、铜和硫氰酸盐质量浓度从150.84 mg/L、121.46 mg/L、252.65 mg/L降至0.44 mg/L、86.17 mg/L、1.23 mg/L,回收金、银、铜的产值为116.62元/m^(3),扣除药剂成本后产生经济效益55.44元/m^(3)。研究结果为类似氰化企业铜氰贫液的净化处理提供参考。

中药复方的现代基础研究进展述评

中药复方的现代基础研究是中药现代化发展的必经之路。本文从中药复杂作用模式解析研究策略与方法、中药直接靶点发现技术与应用、系统生物学驱动的中药复杂作用解析三个方面,对中药复方的现代基础研究进行综述,并对其未来发展进行展望。

钛基纳米复合材料的制备及可见光降解水中污染物性能研究

随着医药科技的发展,抗生素污染逐渐严重。针对环境污染等系列污染物问题,光催化成为了一门处理污染物的热门技术。光催化材料经常使用的有二氧化钛,二氧化钛的优点有健康环保、无污染、容易获取、光催化效率高、储备量大。光催化技术具有成本廉价、简单易操作、太阳能方便获取等优点,为解决环境污染问题提供了有效的途径。为了解决环境污染,修饰二氧化钛的缺陷,提升二氧化钛性能,提出以TiO_(2)为主体,通过TiO_(2)与窄带隙半导体CdS复合,用溶剂热合成法制备出TiO_(2)/CdS二元复合物,增强TiO_(2)对于可见光区间吸收。为了提升降解效果,引入MOF材料UiO-66,制备TiO_(2)/CdS/UiO-66三元复合材料,增大比表面积,提升材料去污能力。

以天然产物中有机化合物为配体的金属配合物研究进展

从天然产物中发现结构新颖、具有良好生物活性的化学成分,是当前新药研发的有效途径之一,但当前的研究主要集中于其中的有机化合物。现有研究表明,天然产物中的微量金属元素与有机化合物在提取过程中可能会形成多种多样的金属配合物,这些金属配合物对与对应的单体有机化合物相比药理活性可能会发生变化,因此,金属配合物很可能也是天然产物中重要的药效物质。本文对近年来以天然产物中有机化合物为配体的金属配合物及其药理活性研究进行了归纳总结,并对此类化合物发展趋势和应用前景作出展望,为其进一步深入研究及开发利用提供一定的参考价值。

校园复合功能单体建筑设计

对复合化建筑的设计理念做出了详细的介绍,在此基础上分析了设计时须考虑的因素,并以具体工程为实例,针对综合楼复合化设计中的功能复合、空间复合、文化复合、景观复合设计要点展开了详细的研究,本研究致力于提升校园建筑设计的可持续性,改善学校的教学与生活质量。

厚壁管道复杂坡口自动焊接运动控制模型设计

针对提高厚壁管道焊接实际情况中复杂多变的复合型坡口的焊接精确性与稳定性,完成了复杂坡口自动焊接运动控制模型的设计,实现多轴焊接机器人更精确、稳定的自动焊接功能。模型通过坡口多层多道模型和多轴电机运动模型的整合,实现坡口的简化、层数道数的修正及通过数据处理得出控制器脉冲值与电机实际行程的关系,最终完成坡口的填充。且成型效果良好,无裂纹、气孔、夹渣等焊接缺陷,焊接质量较好,符合工业化的要求。该模型的建立解决了焊接中由人工视觉手动矫正焊枪位置的不精确和通过电流大小判断电弧相关信息存在噪声干扰大而不稳定的问题,为厚壁管道焊接中相对复杂的一类复合型坡口提供一套可行的理论依据,以提供更方便、精确的自动焊接控制。