四硫氰合钴(Ⅱ)酸钡的18-冠-6配合物的研究

制备了四硫氰合钴(Ⅱ)酸钡的18—冠—6配合物,确定了它的组成,对它进行了红外光谱、质谱、热分析等多项物现性能的测试,并将测试结果结合已测定的配合物的结构进行了讨论。     

18-冠-6铵与硫氰酸银配合物的晶体和分子结构

用凝胶法生长出规则八面体形无色配合物单晶体,在ENRAF-NONLUSCAD4四园衍射仪上,用2461个独立可观察衍射数据,用Patterson函数法和多次△F合成,得到配合物的全部结构参数。结构偏差因子R=0.072,R_w=0.081晶体属单斜晶系,空间群为P_(21)/n。晶胞参数:a=9.032(2),b=14.243(4),C=35.092(6),β=105.5°,Z=4。晶体密度的计算值:D_(eal)=1.546g/cm~3。经元素分析和X射线结构分析,确定晶体的化学式为[(NH_4)(18C6)]_2[Ag_2相似文献   

亚硝酰基钼、钨配合物及其铁杂核簇合物

一氧化氮具有电子给予体和受体的双重性质,在过渡金属配合物中亚硝酰基以线型或弯曲型端基,桥式或面桥式配基配位,很早便引起了结构化学家的注意。这些不同的键合模式影响亚硝酰基的反应能力,它可与亲电试剂如质子酸或路易斯酸反应,也可以与亲核试剂如碳阴离子反应。可以作为氧源与 CO 发生氧化还原反应减少内燃机废气污染,也可以与有机配体发生分子内插入反应,形成新的碳氮     

铁系元素冠醚配合物的研究——Ⅱ. 铁系氯化物与4''-碘苯并-15-冠-5固态配合物的合成与性质

对碱金属、希土与苯并-15-冠-5冠醚配合物的研究指出,4′-取代单苯并冠醚的阳离子配合物的稳定性及其他性质,受取代基电子效应的影响,给电性取代基可增加芳醚氧原子上的电子密度,改变冠氧的极性,从而影响其配位能力,扩大希土配合物之间性质上的差别,达到分离的目的。对于铁系元素,文献报导甚少。我们继Ⅰ之后,又合成了三氯化铁水合物与4′-碘苯并-15-冠-5固态配合物,并研究了其性质。     

单核锰配合物对几类氧化-还原酶的功能模拟

金属锰存在于多种氧化-还原酶中。其中,锰超氧化物歧化酶(Mn Superoxide Dismutase)及锰过氧化物酶(Mn Peroxidase)活性中心的锰结合位点,根据其结构特征,可将其视为精巧的单核锰配合物,因而人们通常以小分子配合物来模拟酶活性中心的结构及功能;另外,细胞色素P450是一种能够催化烯烃环氧化等诸多反应的单加氧酶,某些单核锰配合物能够起到与其类似的催化氧化效果。本文介绍了几类氧化-还原酶的结构特征和催化机理,总结了以小分子锰配合物作为酶功能模拟物的研究进展。     

铁系元素冠醚配合物的研究——Ⅸ.铁系氯化物与4′-溴-5′-硝基苯并-15-冠-5固体配合物的合成及性质

近年来,有关过渡金属离子冠醚配合物的研究虽有一些报道,但这些研究所涉及的配体大多数是单取代苯并冠醚,对双取代苯并冠醚配位的研究则很少。为了进一步弄清取代冠醚对过渡金属配位性能的影响,我们研究了混合双取代的苯并-15-冠-5,根据文献[2,3]合成了4′-溴-5′-硝基苯并-15-冠-5,并制得了一种新的配合物FeCl_3·L,经性质证明此配合物是1:1型非溶剂合、不含水的固体配合物,其三个Cl~-离子位丁配合物的外界。     

混合价配合物的振动偶合模型及进展

本文讨论了混合价二聚配合物的振动偶合模型，并应用Ｃｒｅｕｔｚ－Ｔａｕｂｅ（Ｃ－Ｔ）离子－（μ－吡嗪）二（五氨合钌）（５＋），计算其势能函数，混合价跃迁带的形状及ＥＰＲｇ值等性质，还指出了混合价三聚物，四聚物的振动偶合模型的新进展。     

铁系元素冠醚配合物的研究--Ⅰ.铁系氯化物与4''-硝基-苯并15-冠-5配合物的合成和性质

本文报导铁系氯化物,FeCl_3、CoCl_2和NiCl_2(均为水合物)与4—硝基—苯并—15—冠—5(L)固态配合物的合成和性质。 合成的FeCl_3·L·2H_2O是一种新的冠醚配合物。经元素分析、红外光谱,紫外光谱、热谱及X—射线衍射分析证明是1:1型,非溶剂化、含有两个结晶水的固态配合物,并且研究了其他有关性质。 在同样条件下,CoCl_2和NiCl_2皆不与4′—硝基—苯并—15—冠—5配体生成配合物。从中可望得到铁系元素分离的新方法和新途径。     

铁系元素冠醚配合物的研究——V.三氯化铁与4′-溴苯并-15-冠-5固态配合物的合成和性质

本文报导了三氯化铁(水合物)与4′-溴苯并-15-冠-5(L)固态配合物的合成,对合成的新配合物,进行了元素定量分析及摩尔电导测定,并作了红外光谱、紫外光谱,热重和差热以及X-射线粉末衍射分析的性质表征。从而证明,该配合物中FeCl_3与配体L比为1:1,是溶化剂,含有结晶水的固态配合物。     

铁系元素冠醚配合物的研究——Ⅲ.三氯化铁与3′,4′—二硝基苯并—15—冠—5配合物的合成和性质

本文报道,三氯化铁(水合物)与3’,4’—二硝基苯并—15—冠—5固态配合物的合成。对合成的新配合物,作了元素定量分析。进而对该配合物的红外光谱、紫外光谱、热重、差热分析和X—射线粉末衍射分析等进行了研究。从而证明,该配合物为1:1型,非溶剂化和不含结晶水的固态配合物。 在同样条件下,3’,4’—二硝基苯并—15—冠—5与CoCl_2、NiCl_2(均为水合物)不形成配合物。     

二氧化碳和丙烯直接合成甲基丙烯酸的NiPMo/TiO2催化剂的研究

用溶胶-凝胶法以磷钼酸(MPA)的镍盐溶液水解钛酸四丁酯制备了NiPMo/TiO2催化剂.使用ICP、 XRD、 TG-DTA、 IR、 TPD-MS和微反应技术研究了催化剂的化学组成、热稳定性、化学吸附性质和催化反应性能.杂多钼酸盐与TiO2通过O2-在TiO2表面发生了键合.在623 K下,杂多阴离子仍保持原有的Keggin结构.CO2在Lewis酸位Ni(Ⅱ)和Lewis碱位Ni-O-Mo的桥氧协同作用下生成CO2卧式吸附态Ni(Ⅱ)←O-(CO)←(O--Ni).丙烯有多种吸附态在催化剂上吸附.在563 K、 1 MPa和空速1500 h-1的反应条件下,丙烯的摩尔转化率为3.2%,产物MAA选择性为95%.     

衬底上石墨烯制备及改性研究

大面积高质量石墨烯的制备对石墨烯电子特性及石墨烯基纳器件相关研究有重要意义。本文综述了近几年来衬底上制备石墨烯的相关实验以及衬底与石墨烯相互作用研究的重要进展。目前,采用化学气相沉积、外延生长等方法可在衬底表面上制备出较大面积、高质量的石墨烯材料。衬底与石墨烯相互作用和界面间晶格匹配、原子成键及电荷转移等密切相关,其对吸附石墨烯的几何结构、能带结构及电子特性等产生明显影响。实验与理论计算的结合可望加深衬底与石墨烯作用机理的理解,指导衬底上石墨烯制备及改性的进一步研究。     

Elemental Characterization of Ciders and Other Low-Percentage Alcoholic Beverages Available on the Polish Market

Seventy-three samples of alcoholic beverages and juices that were purchased on the Polish market and home-made were analyzed for their elemental profiles. The levels of 23 metals were determined by ICP-MS (Ag, Ba, Bi, Cd, Co, Cr, Li, Mn, Ni, Pb, Sr and Tl), ICP-OES (Al, B, Ca, Cu, Fe, K, Mg, Na, Ti and Zn) and CVAAS (Hg) techniques in twenty-five samples of ciders widely available on the Polish market; six samples of home-made ciders; two samples of juices used in the production of these ciders; and forty samples of low-percentage, flavored alcoholic beverages based on beer. The gathered analytical data confirmed that the final elemental fingerprint of a product is affected by the elemental fingerprint of the ingredients used (apple variety) as well as the technology and equipment used by the producer, and in the case of commercial ciders, also the impact of type of the packaging used was proven. These factors are specific to each producer and the influence of the mentioned above parameters was revealed as a result of the performed analysis. Additionally, the inclusion of the home-made ciders in the data set helped us to understand the potential origin of some elements, from the raw materials to the final products. The applied statistical tests revealed (Kruskal–Wallis and ANOVA) the existence of statistically significant differences in the concentration of the following metals: Ag, Al, B, Bi, Co, Cr, Cu, Fe, K, Li, Mg, Na, Ni, Ti and Zn in terms of the type of cider origin (commercial and home-made). In turn, for different packaging (can or bottle) within one brand of commercial cider, the existence of statistically significant differences for Cu, Mn and Na was proved. The concentrations of all determined elements in the commercial cider from the Polish market and home-made cider samples can be considered as nontoxic, because the measured levels of elements indicated in the regulations were lower than the allowable limits. Moreover, the obtained results can be treated as preliminary for the potential authentication of products in order to distinguish the home-made (fake) from the authentic products, especially for premium-class alcoholic beverages.     

MISCIBILITY AND MORPHOLOGY OF THIN FILMS OF BLENDS OF POLYSTYRENE WITH BROMINATED POLYSTYRENES： EFFECTS OF VARYING THE MOLECULAR WEIGHT, BROMINATION DEGREE AND ANNEALING

Thin films of incompatible polymer blends can form a variety of structures during preparation and subsequent annealing process. For the polymer blend system consisting of polystyrene and poIy(styrene-co-p-bromo-styrene), i.e., PS/PBrxS, its compatibility could be adjusted by varying the degree of bromination and the molecular weight of both components comprised, in this paper, surface chemical compositions of the cast and the annealing films were investigated by X-ray photoelectron spectroscopy (XPS) and contact angle measurement; meanwhile, surface topographical changes are followed by atomic force microscopy (AFM). In addition, substantial attention was paid to the effect of annealing on the morphologic variations induced by phase separation and/or dewetting of the thin film. Moreover, the influences of the molecular weight, Aw, as well as the brominated degree, x%, on the sample surface are explored systematically, and the corresponding observations are explained in virtue of the Flory-Huggins theory, along with the dewetting of the polymer thin film.     

火场助燃剂检验鉴定的干扰研究进展

火灾是影响公共安全最为常见的灾害之一,而放火更是严重威胁人民群众生命财产安全,属于典型的暴力犯罪.犯罪嫌疑人为了达到有效快速放火的目的,往往使用助燃剂实施放火,因而助燃剂的检验鉴定对于认定火灾性质起着至关重要的作用.然而火场情况复杂,容易对助燃剂物证检验鉴定产生较大干扰.在火灾发生发展的过程中,火场高温热环境会作用于已...     

Self-Assembling Drug Formulations with Tunable Permeability and Biodegradability

This review focuses on key topics in the field of drug delivery related to the design of nanocarriers answering the biomedicine criteria, including biocompatibility, biodegradability, low toxicity, and the ability to overcome biological barriers. For these reasons, much attention is paid to the amphiphile-based carriers composed of natural building blocks, lipids, and their structural analogues and synthetic surfactants that are capable of self-assembly with the formation of a variety of supramolecular aggregates. The latter are dynamic structures that can be used as nanocontainers for hydrophobic drugs to increase their solubility and bioavailability. In this section, biodegradable cationic surfactants bearing cleavable fragments are discussed, with ester- and carbamate-containing analogs, as well as amino acid derivatives received special attention. Drug delivery through the biological barriers is a challenging task, which is highlighted by the example of transdermal method of drug administration. In this paper, nonionic surfactants are primarily discussed, including their application for the fabrication of nanocarriers, their surfactant-skin interactions, the mechanisms of modulating their permeability, and the factors controlling drug encapsulation, release, and targeted delivery. Different types of nanocarriers are covered, including niosomes, transfersomes, invasomes and chitosomes, with their morphological specificity, beneficial characteristics and limitations discussed.     

化学平衡有向图

根据化学平衡原理和图论中的基本概念，提出了一种适用于化学平衡计算的赋权有向图。这种有向图具有三个重要性质：其一，边的方向改变则该边的权随着取逆(取原权的倒数或负值)；其二，顺乘逆除(或顺加逆减)一条路上的各权得到自起点至终点的累积权；其三，回路的权等于1(或零)。本文主要叙述这种图的提出及其在化学平衡中的初步应用。     

Diffusion of symmetrical and spherical solutes in protic,aprotic, and hydrocarbon solvents

The diffusion coefficients of a series of symmetrical tetraalkyltins (tetramethyltin, tetraethyltin, tetrapropyltin, tetrabutyltin, tetradodecyltin) of the gases argon, krypton, xenon, methane, and tetramethylmethane and of carbon tetrachloride and tetraethylmethane in hexane, decane, and tetradecane at 25°C have been determined using the Taylor dispersion technique. Diffusion coefficients for the gases in acetone, 2-propanol, 1-butanol, and 1-octanol were also determined. Deviations from the predictions of Stokes' law were found to be large, and the magnitude of the deviation can be directly related to solute size. The predictions of the Hubbard-Onsager equation were tested using the diffusion data.     

稀土及杂质元素对ZA27合金晶间腐蚀的影响

To understand the influence of impurities and rare earth elements in nature on the intergranular corrosion of the zinc-aluminum alloys, taking efficient methods to retard the inter granular corrosion, the atomic cluster of α phase grain boundary including impurities (Pb, Sn, Cd), rare earth elements (La, Y) and phase grain was constructed by computer programming based on the coincidence-site lattice theory. The recursion method was used to calculate the charge transfer over the grain boundary of α phase, and discuss influence of impurities (Pb, Sn, Cd) and Rare Earth elements (La, Y) on the electrode-potential of Zn and Al. The results shows that impurity elements (Pb, Sn, Cd) can increase the charge transfer between atoms over the grain boundary, leading to the large difference of electrode-potential between Zn and Al. Therefore the eroding is speeding up, but the RE element can reduce the charge transfer between atom sover the grain boundary, and lower the difference of electrode-potential between Zn and Al. Thus RE element is of the role of restraining the inter granular corrosion of zinc-aluminum alloys.     

Contributions to the Chemistry of the Binary Compounds of the Transition Elements

Phase and structural relationships of the sulfur, selenium, and tellurium compounds of the 4d and 5d transition elements of groups IV to VII of the periodic system are discussed. Homologous elements behave very similarly with respect to the chalcogens, and this is particularly the case for niobium and tantalum, and for molybdenum and tungsten. However, zirconium, niobium, and molybdenum have a greater tendency towards formation of chalcogen-poor phases than their homologues hafnium, tantalum, and tungsten. Subchalcogenides are known only for zirconium and niobium. The number of phases and the tendency towards formation of solid solutions are considerably smaller among the tellurides than among the sulfides and selenides. The crystal structures of the telluride phases also differ from those of the sulfide and selenide phases of analogous composition. In addition, a review of the phase and structural relationships of the arsenic and antimony compounds of the 4d and 5d transition elements of groups V to VII is given.