在聚乙烯吡咯啉酮—盐—水的液—固萃了以体系中溴络阴离子的萃取…

本文研究了在聚乙烯吡咯啉酮－盐－水度的液－固萃取体系中，Ａｕ（Ⅲ）、Ｂｉ（Ⅲ）、Ｚｎ（Ⅱ）和Ｆｅ（Ⅲ）与Ｂｒ＾－形成的络阴郭，在两相间的分配行为。     

聚乙二醇2000-吐温80-(NH4)2SO4-H2O液-固萃取体系

研究了聚乙二醇2000-吐温80混合聚合物水溶液在(NH₄)₂SO₄存在下分成液-固两相的条件和水溶性螫合剂及金属离子螫合物在两相间的分配行为,实现了Zr(Ⅳ)-Sc(Ⅲ)、Fe(Ⅲ)-Sc(Ⅲ)的定量萃取分离,初步探讨了混合聚合物相的萃取机理。     

聚乙烯吡咯啉酮—盐—水液—固萃取体系分离纯化α—淀粉酶的研究

本文研究了α－淀粉酶，酪蛋白、牛血清白蛋白在聚乙烯吡咯啉酮－盐－水液－固萃取体系中的萃取行为，着重讨论了ＰＨ值、（ＮＨ４）２ＳＯ４浓度及激活剂ＮａＣｌ对酶萃取订的影响。     

在聚乙烯吡咯啉酮-盐-水的液-固萃取体系中溴络阴离子的萃取行为

本文研究了在聚乙烯吡咯啉酮（PVP）－盐－水的液－固萃取体系中，Au（Ⅲ）、Bi（Ⅲ）、Zn（Ⅱ）和Fe（Ⅲ）与Br形成的络阴离子，在两相间的分配行为。在硫酸和盐酸介质中，Au（Ⅲ）有很高的萃取率，Fe（Ⅲ）的萃取率很低，而Bi（Ⅲ）和Zn（Ⅱ）的萃取率则受溶液的酸度、NH；Br的浓度及溶液介质的影响。在硫酸介质中，通过控制溶液的酸度和NH4Br的浓度，实现了Bi（Ⅲ）－Fe（Ⅲ）、Au（Ⅲ）－Zn（Ⅱ）及Au（Ⅲ）－Fe（Ⅲ）等的定量萃取分离与测定。     

分散液液微萃取-气相色谱-质谱法测定水样中4种嗅味物质

以四氯乙烯作萃取剂,以丙酮为分散剂对水样中4种嗅味物质,二甲基异莰醇、土臭素、β-环柠檬醛和β-紫罗兰酮进行分散液液微萃取,提取液供气相色谱-质谱仪分析。在选择离子监测模式下,4种嗅味物质的线性范围均为0.05～20μg.L-1。二甲基异莰醇、土臭素、β-环柠檬醛和β-紫罗兰酮的检出限(3S/N)分别为0.03,0.01,0.02,0.01μg.L-1。方法用于自来水和河水样品分析,4种嗅味物质的回收率在87.7%～102%之间,测定值的相对标准偏差(n=6)在1.8%～7.8%之间。     

3-(1′-烃氧亚氨基)乙基-4-羟基吡咯啉-2-酮类衍生物的合成与生物活性

以氨基酸乙酯为原料合成8种3-乙酰基-4-羟基吡咯啉-2-酮的类似物A, A与3种烃氧基胺盐酸盐反应合成了20个肟醚类衍生物3-(1'-烃氧亚氨基)乙基-4-羟基吡咯啉-2-酮(B), 其结构经 1H NMR, MS, IR和元素分析表征. 初步生物活性测定结果表明合成的化合物B具有一定的除草活性和抑制真菌活性.     

液/液界面萃取循环伏安法测定Pb2+离子

利用吡咯烷二硫代氨基甲酸铵作为螯合剂,甲基异丁酮作为萃取剂,将水相中的Pb2+萃取到有机相中,利用经典的三电极系统研究该有机相在液/液界面的伏安特性.实验结果表明,该电化学过程是一个不可逆过程,Pbα的萃取物从有机相转移到水相.铅萃取物的转移峰在0.16 V vs.SCE处,并且在1.0×10-5～9.0×10-5mol/L范围内与峰电流大小成正比.这一方法为工业废水中铅的在线、现场测定提供了可靠、灵敏的监测方法.     

在线固相微萃取在烟用料液的指纹图谱中的应用

为解决现有烟用料液指纹图谱的信息量少、水溶性成分反映不充分、特征反映不明显的问题,本文建立了烟用料液在线固相微萃取-气相色谱指纹图谱分析方法。运用正交实验设计,比较萃取头、萃取时间、萃取温度、脱附时间、NaCl的加入量这五个因素对固相微萃取结果的影响。引用信息量和峰面积作为判别准则,确定固相微萃取的最佳条件。比较在线固相微萃取方法与乙醚液-液萃取方法,结果表明固相微萃取方法用于测定烟用料液的指纹图谱具有较高的信息量和较好的重现性。采用在线固相微萃取结合气相色谱-质谱(GC-MS)分析烟用料液结果进行定性分析,共鉴定出34种组分,其主要成分为丙二酸二乙酯、胡椒醛、对甲氧基苯乙酮、香兰素、茄酮等。     

4H—1,2,4—三唑—4—基酮和醇的合成及其生物活性

1-(4H-1,2,4-三唑-4-基)频哪酮(2)与卤代烃在相转移催化条件下反应,得到具有较高产率的4H-1,2,4-三唑-4-基酮(3);进一步用硼氢化钾还原,得到近乎定量产率的醇(4)。初步的生物活性测定表明3和4有一定的延缓植物生长的作用和杀菌活性。     

液/液界面萃取循环伏安法测定Pb2+离子研究

本文利用吡咯烷二硫代氨基甲酸铵（APDC）作为螯合剂,甲基异丁酮（MIBK）作为萃取剂,将水相中的Pb2+萃取到有机相中,利用经典的三电极系统研究该有机相在液/液界面的伏安特性。实验结果表明,该电化学过程是一个由扩散控制的不可逆过程,Pb2+的萃取物从有机相转移到水相。铅萃取物的转移峰在0.16V vs.SCE处,并且在1.0×10-5~ 9.0×10-5mol/L范围内与峰电流大小成正比。这一方法为工业废水中铅的在线、现场测定提供了可靠、灵敏的监测方法。     

Ternary systems LiBr-Li2MoO4-Li2WO4 and LiF-Li2MoO4-Li2WO4

The ternary systems LiBr-Li₂MoO₄-Li₂WO₄ and LiF-Li₂MoO₄-Li₂WO₄ were studied by differential thermal analysis. The fields of crystallizing phases are delimited, and di- and monovariant equilibria for surfaces and monovariant curves are described.     

Kristallstrukturen von MgCr2O4-Typ Li2VCl4 und Spinell-Typ Li2MgCl4 und Li2CdCl4

Crystal Structures of MgCrO₄-type Li₂VCl₄ and Spinel-type Li₂MgCl₄ and Li₂CdCl₄ The crystal structures of the ternary lithium chlorides Li₂MCl₄ (M = Mg, V, Cd) have been determined firstly by X-ray single-crystal experiments. Li₂MgCl₄ and Li₂CdCl₄ crystallize in an inverse spinel structure (space group Fd3 m, Z = 8, a = 1 040.1(2) and 1 062.06(9) pm, structural parameters u = 0.25699(2) and 0.2550(1), R = 1.7 and 3.7% for 218 and 211 unique reflections). The Li? Cl distances of the tetrahedrally coordinated Li⁺ ions are significantly greater than calculated with Shannon's crystal radii ( > 238 ± 1 instead of 233 pm). Contrary to the results of X-ray powder data reported in the literature, Li₂VCl₄ crystallizes in the distorted spinel structure of MgCr₂O₄ type (space group F4 3m, Z = 8, a = 1 037.49(2) pm, R = 5.9% for 217 unique reflections). The decrease of the site symmetry of the octahedrally coordinated ions (V²⁺, Li⁺) from 3 m to 3m resulting in contracted and widened tetrahedral M₄ entities of the spinel structure is obviously caused by V? V metal—metal bonds (shortest V? V distance 366.2(7) pm).     

Zur Kenntnis der Chlorid-Spinelle Li2MgCl4, Li2MnCl4, Li2FeCl4, Li2CdCl4

About the Chloride Spinels Li₂MgCl₄, Li₂MnCl₄, Li₂FeCl₄, Li₂CdCl₄ FIR, Raman, and X-ray data of the spinel type chlorides Li₂TCl₄ (T = Mg, Mn, Fe, Cd) are presented. The vibrational spectra indicate that there is no 1:1 ordering on the octahedral sites of the lattice. Both DTA measurements and high temperature X-ray photographs show that the chloride spinels undergo a reversible phase transition to a cubic high temperature defect structure at 535°C (Li₂MgCl₄), 460°C (Li₂MnCl₄) and 385°C (Li₂CdCl₄), which has unit cell dimensions two times smaller than the spinel lattice. Disordering of the lithium sublattice still begins at much lower temperatures, as measurements of the electric conductivity indicate.     

Darstellung und Struktur von BaAl2Se4, BaGa2Se4, CaGa2Se4 und Caln2Te4

Preparation and Crystal Structure of BaAl₂Se₄, BaGa₂Se₄, CaGa₂Se₄, and CaIn₂Te₄ The new compounds BaAl₂Se₄, BaGa₂Se₄, CaGa₂Se₄ and CaIn₃Te₄ crystallize with constants see “Inhaltsübersicht”. The structures are strongly related to the TlSe structure.     

Li~2SO~4-MgSO~4、LiSO~4-Li~4SiO~4体系的研究

本文用X射线衍射(高温、室温)和热分析(DTA、DSC、TGA)等方法测定了Li~2SO~4-MgSO~4和Li~2SO~4-Li~4SO~4体系相图,并研究了化合物的性能和晶体结构。Mg~4Li~2(SO~4)~5在840℃由包晶反应形成,它在105℃分解为Li~2SO~4为基的固溶体和MgSO~4.在105℃反应时,形成每摩尔的Mg~4Li~2(SO~4)~5吸热2.57kJ,反应激活能为173.5kJ/mol. Mg~4Li~2(SO~4)~5属正交晶系,在180℃的点阵常数α=8.577A,b=8.741A, c=11.918A, 可能的空间群为P222或Pmmm,Z=2。Li~8-2x(SiO~4)~2-x(SO~4)~x是在953℃由包晶反应形成的新相.随着温度的降低,相区扩大,在室湿x=0.96-0.58.该相属正交晶系,空间群为Pmmn,Z=2.晶体的点阵常数在x=0.8时有一定最大值,a=5.002A,b=6.173A, c=10.608A.Li~g-2x(SiO~4)~2-x(SO~4)~x在空气中能吸收7.6wt%的水蒸汽和其他气体,脱水温度高于350℃,水份的吸脱不改变晶体结构,与沸石分子筛具有相似性质,脱水激活能为171.5kJ/mol.熔化后的Li~2SO~4-MgSO~4和Li~2SO~4-Li~4SiO~4试样以10℃/min速率降温,分别形成亚稳态共晶体系。     

Studies on Li2SO4-MgSO4 and Li2SO4-Li4SiO4 systems

The phase equilibria as well as the properties and crystal structures of the compounds formed in both Li₂SO₄-MgSO₄ and Li₂SO₄-Li₄SiO₄ systems have been studied by means of x-ray diffraction technique (at high and room temperatures) as well as by the thermal analyses (DTA, DSC, TGA, etc.). In Li₂SO₄-MgSO₄ system there exists a compound Mg₄Li₂(SO₄)₅ formed by peritectic reaction at 840°C and decomposed at 105°C into the Li₂SO₄-base solid solution and MgSO₄ · Mg₄Li₂(SO₄)₅ and Li₂SO₄-base solid solution conduct an eutectic reaction at 663°C with the composition of eutectic point lying in 22 mol% MgSO₄. The solubility of MgSO₄ in Li₂SO₄ is a little smaller than 10 mol% while at the same time the Li₂SO₄ phase transition temperature decreases from 574 to 560°C On the other hand, no noticeable solid solubility of Li₂SO₄ in MgSO₄ has been observed. The reaction is an endothermal one and its heat of formation is 2.57 kJ/mol. The activation energy of the reaction calculated by thermal peak displacement method at various heating rates is 173.5 kJ/mol (1.80 ev). The crystal Mg₄Li₂(SO₄)₅ belongs to orthorhombic system with lattice parameters at 180°C: a = 8.577, b=8.741, c= 11.918 Å. The space group seems to be either P222 or P mmm. Assuming that there are two formula units in a unit cell, the density calculated is then 2.20 g/cm³ very close to that of Li₂SO₄ or MgSO₄. Meanwhile, in Li₂SO₄-Li₄SiO₄ system a new phase Li_8-2x(SiO₄)_8-x(SO₄)_x is formed by peritectic reaction at 953°C with a range of composition x=0.96 ?0.58. The crystal belongs to ortho-rhombic system with lattice parameters at x=0.8: a = 5.002, b= 6.173 and c=10.608Å. The density observed is 2.31 g/cm³ and there are 2 formula units in an unit cell. It is shown from the measurements of piezoelectric and laser SHG coefficients of the crystal that the crystal posseses a symmetrical center with the space group belonging to P mmn. The lattice parameter c has a maximum at x=0.8. In the air Li_8-2x(SiO₄)_2-x(SO₄)_x can absorb 7.6 wt% water vapour and other gases which can only be desorbed by heating it at a temperature above 350°C. Neither absorption nor desorbtion can change its crystal structure, a characteristic similar to that of zeolite molecular sieve. The dewater activation energy of Li_8-2x(SiO₄)_2-x(SO₄)_x is 171.5 kJ/mol. Li_8-2x(SiO₄)_2-x(SO₄)_x and Li₄SO₄ bring about an eutectic reaction at 823°C with its eutectic composition being 12 mol% Li₄SiO₄. No observable solubility of Li₄SiO₄ in Li₃SO₄ has been noticed. The solubility of Li₂SO₄ in Li₄SiO₄ is approximately equal to 5 mol%. With Li₂SO₄ being dissolved in, the phase transition temperature of Li₄SiO₄ is decreased. After being fused, the specimens Li₃SO₄-MgSO₄ and Li₂SO₄-Li₄SiO₄ are cooled at a rate of 10°C/min, their metastable eutectic systems are resulted respectively.     

Synthesis and Characterization of Gd2[Pt2(SO4)4(HSO4)2](HSO4)2

Red single crystals of Gd₂[Pt₂(SO₄)₄(HSO₄)₂](HSO₄)₂ (triclinic, , Z = 1, a = 844.02(9), b = 908.50(9), c = 939.49(8) pm, α = 107.73(1)°, β = 112.10(1)°, γ = 103.53(1)°) were obtained by the reaction of [Gd(NO₃)(H₂O)₇][PtCl₆]·4H₂O with sulfuric acid at 320 °C in a sealed glass ampoule. In the crystal structure, Pt₂ dumbbells are coordinated by four chelating sulfate groups and two monodentate hydrogensulfate ions. Two further HSO₄^? ions are not bonded to the Pt₂ dumbbell. The Gd³⁺ ions are eightfold coordinated by oxygen atoms. The IR data of Gd₂[Pt₂(SO₄)₄(HSO₄)₂](HSO₄)₂ are typical for these type of compounds. The thermal decomposition of the compound leads to elemental platinum and Gd₂O₃.     

Four-component system LiF-K2WO4-CaF2-CaWO4

The four-component system LiF-K₂WO₄-CaF₂-CaWO₄ has been studied by physicochemical analysis. The phase and crystallization trees have been predicted a priori and have been experimentally verified by constructing a topological model of the phase diagram and by solving the equations expressing the general law of liquidus surface formation. The heat-storage properties of the eutectic compositions are evaluated.     

Photolyse von 2, 2, 4, 4-Tetramethylcyclobutanon-Derivaten

The photochemical reactions of the 2, 2, 4, 4-tetramethylcyclobutanones 1–6 carrying various substituents in 3-position were investigated. The major reaction in alcoholic solution or in the presence of other protic compounds was the formation of the semicyclic acetals 7–12 . Parallel to this reaction decarbonylation occurred, leading to stable cyclopropane derivatives in some cases, depending on the substituents present. Cyclopropanes with an exocyclic double bond underwent ring opening easily or, in case of an exocyclic carbon-nitrogen double bond, added alcohol, thus forming cyclopropane O, N-ketals. Alkyl-acyl biradicals are proposed as common intermediates for both photoreactions. Based on analogy to similar photoreactions reported in the literature, the formation of the semicyclic acetals is assumed to involve a carbene intermediate.