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。     

FACILE SYNTHESIS OF 4-AMINO-4-DEOXY-4''''-DEMETHYLEPIPODOPHYLLOTOXIN

4-Amino-4-deoxy-4′-demethylepipodophyllotoxin has beendirectly synthesized from 4′-demethylepipodophyllotoxin and HN_3in the presence of BF3·Et_2O,followed by hydrogenation withpalladium on charcoal as catalyst.     

Li_2SO_4-MgSO_4、Li_2SO_4-Li_4SiO_4体系的研究

本文用X射线衍射(高温、室温)相热分析(DTA、DSC、TGA)等方法测定了Li_2SO_4-MgSO_4和Li_2SO_4-Li_4SiO_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.在室温x=0.96—0.58.该相属正交晶系,空间群为.Pmmm,Z=2.晶体的点阵常数在x=0.8时有一最大值,α=5.002A,b=6.173A,c=10.608A.Li_(8-2x)(SiO_4)_(2-x)(SO_4)_x在空气中能吸收7.6wt％的水蒸气和其他气体.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.     

BH_4~-,CH_4,NH_4~ ,AlH_4~-,SiH_4,PH_4~ ,GeH_4的SCF-X_a计算方法研究

本文通过球半径比的优化选择,给出了七个含氢正四面等价电子分子的SCF-X。方法非重叠近似方案的计算结果.就中性分子CH_4,SiH_4及GeH_4而言,总能量和结合能计算值有了显著改进,使SiH_4和GeH_4的成键稳定性得到了合理说明.对离子计算,同时给出了Watson球存在和不存在的计算结果,通过对比,说明自由离子是一种更不稳定的状态,而Watson球确是稳定离子的环境的合理模拟.对离子的结合能也作了讨论,并联系了有关晶体化合物的热稳定性作出了解释.与此同时,还发现优化球半径比与中央原子的电负性存在线性关系,且符合于Virial定理的要求。     

AN SCF-X_αSW STUDY OF BH_4~-, CH_4,NH_4~ , AlH_4~-, SiH_4, PH_4~ AND GeH_4

Through the optimization of sphere radii ratios, seven tetrahedral hydrides species withequal valence electrons are investigated by means of SCF-X_αSW method in muffin-tin ap-proximation scheme. In comparison with those published results, the calculated total statis-tical energies and the corresponding binding energies of neutral molecules concerned have beenmuch better improved, which offers reasonable interpretation of their bonding stabilities, no-tably for SiH_4 and GeH_4. For ionic species, attention is focused on the role of Watson sphere,thus two kinds of calculation with and withcut Watson sphere are simultaneously given for com-parison. It reveals that free ions always behave more unstably and Watson sphere seems tobe a suitable model for describing the environment of a stabilized ion. The calculated bind-ing energies of ions have been utilized to correlate the thermostability trend for a few crystalcompounds. Also, an empirical linear relationship between optimized sphere radii ratios andelee     

Stereoselective Synthesis and Anticancer Activities of New Podophyllotoxin Derivatives:4-β-Cyano-4-Deoxy-4'-Demethylepipodophyllotoxin and 4-β-Carboxyl-4-Deoxy-4'-Demethylepipodophyllotoxin

Podophy1lotoxinl,isolatedfromPodoPhyllumpeIatumL.orPodoPhyllumemodiL.,showshighantitUmoractivity.But,itcatmotbeusedasantitUmoragentclinicallybecauseofitsseriousside-effect.Itssemisyntheticderivatives,EtoPoside2andTeniposide3,arewide-usedasboortantanticancerdrugs'.Howevef,theyhaveseverallimitationssuchaspoorwatersolubilitymetabolicinachvahonanddevelopmentofdrugresistance.Toovercometheselindtations,manyderivahvesofpodophyllotoxinhavebeensynthesizedinmanylaboratories2~5.Ithasbeenrecognisedt…     

Synthesis of Alkyl4(4'-octyloxy-4”-biphenylcarboxy)-benzenesulfonates

Sincethediscoveryoftristableswitching'andthesubsequentidentificationofmesomorphicphasesinMHPOBC2'3I,thesynthesisofnewliquidcrystalshaveattractedmuchattention.Theliquidcrystals,incorporatingtheSatom,suchasthioester4,sulfoxides5andsulfone',havebeenstudied.PrelindnarydatasuggestedthatthisstrUcturalchangefavoredtheformationofsmecticphases.WefirstintroducedsuIfonateintoliquidcrystalsandplannedthesynthesisofthiscategoryinordertostudyitsproperties.Wepresentherethesynthesisandcharacterizationsbase…     

α-Thioureidoalkylation of 4-alkyl- and 4-phenylthiosemicarbazides

Previously unknown 1,3-dialkyl-4,5-bis[4-alkyl(phenyl)thiosemicarbazido]imidazolidine-2-thiones and 4,5,7-trialkylperhydroimidazo[4,5-e]-1,2,4-triazine-3,6-dithiones have been synthesized by the α-thio-ureidoalkylation of 4-alkyl(phenyl)thiosemicarbazides using 1,3-dialkyl-4,5-dihydroxyimidazolidine-2-thiones.     

4 氨基4′ 氰基联苯的合成

４氨基４′氰基联苯,不仅是制备烷氧基联苯的原料,而且可以制备高正介电各向异性液晶及系列酯类液晶材料．但通常要经过酰化、氧化、酰氯化、氨解、脱水、硝化和还原［１］等多步反应,步骤长、收率低,本文用联苯为原料,经过硝化、碘代、氰代和还原反应合成４氨基４′氰基联苯．反应步骤及时间比原路线减少近一半,而且反应条件温和,收率高．联苯（ＣＰ,上海化学试剂一厂）;Ｎ,Ｎ二甲基甲酰胺（ＡＲ,临平化工试剂厂）;氯仿（ＡＲ,沈阳试剂一厂）;亚硫酸氢钠（ＡＲ,大连辽南化学品厂）;碘酸（ＡＲ,北京化工厂）…     

聚乙烯吡咯啉酮—（NH4）2SO4—H2O液—液,液—固萃取体系

研究了聚乙烯吡咯啉酮水溶液在(NH_4)_2SO_4存在下分成液-液或液-固两相的条件和水溶性整合剂及金属离子整合物在该体系两相间的分配行为。实现了Zr(Ⅳ)-La(Ⅲ)的定量萃取分离,初步探讨了聚乙烯吡咯啉酮相的萃取机理。     

PEG/(NH4)2SO4双水相体系萃取甘草中的有效成分

甘草的主要有效成份甘草酸具有消炎解毒、抗氧自由基、调节机体免疫力等作用,目前已被广泛应用于食品、饮料、化妆品、医药、卷烟等行业。工业上广泛应用的是水提法,该法操作容易、设备简单、溶剂价廉,但提取效率不高,易造成资源浪费。双水相萃取技术(Two-aqueous phase extraction,简称．ATPS),是近年出现的新型生物化工分离技术。由于双水相萃取分离过程条件温和、可调节因素多、易于放大和操作,不存在有机溶剂残留问题,特别适用于生物物质及天然资源中有效成分的分离和提纯。     

硫酸铵存在下碘化钾-乙醇体系萃取分离镉

传统萃取分离法由于采用与水互不相溶的有机溶剂 ,对那些萃取反应速度慢、传质速率低、分配比小的体系需在振荡器上进行较长时间振荡或多次萃取才能达到定量萃取 .均相萃取、异相分离萃取体系由于可以克服异相萃取分离技术中一些缺点而受到重视[1,2 ].本文以乙醇为溶剂 ,均相萃取、异相分离镉 .试验表明 ,硫酸铵存在下 ,乙醇与水分相过程中 ,Ｃｄ(Ⅱ )与Ｉ- 形成的ＣｄＩ2 - 4 与质子化乙醇 (Ｃ2 Ｈ5ＯＨ 2 )形成电中性缔合物 (Ｃ2 Ｈ5ＯＨ 2 ) 2 ＣｄＩ2 - 4 被乙醇相完全萃取 .能使Ｃｄ(Ⅱ )从Ｆｅ(Ⅲ )、Ｃｏ(Ⅱ )、Ｎｉ(Ⅱ )、Ｍｎ(Ⅱ )…     

Triton X－100－（NH_4）_2SO_4－H_2O液－固萃取体系中以N

ＴｒｉｔｏｎＸ－１００的盐水溶液会分成聚合物固相和盐水相。这是一种新的非有机溶剂液－固萃取体系。研究了在该萃取体系中用ＮＨ４Ｉ作萃取剂，Ｐｄ（Ⅱ）、Ｂｉ（Ⅲ）、Ｚｎ（Ⅱ）和Ｆｅ（Ⅲ）等金属离子的萃取行为。实现了Ｂｉ（Ⅲ）—Ｆｅ（Ⅲ）和Ｐｄ（Ⅱ）—Ｚｎ（Ⅱ）间的定量萃取分离与测定。实验结果表明，金属离子与Ｉ－形成络阴离子被萃入聚合物固相。     

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。     

Extraction from mixed HCl−H2C2O4 solutions purification of some actinides

Carrier-free⁹⁰Y isotope was used to study the distribution between the aqueous solution of nitric acid and sodium nitrate and HDOP in cyclohexane. The distribution coefficients (D) were measured as a function of the acidity and the nitrate concentration (M_{NO 3}) in the aqueous phase. The acid dependence was studied in a HNO₃ concentration range of 1–14M. The curve IgD vs. lgM_{HNO 3} in the range of 1–4 gives a slope of 3. The anion effect of nitrate ions shows a complexing influence on the yttrium ions changing its distribution between the two phases. The results can be useful in hydrometallurgical processes in which the solutions are highly acidic and contain a large amount of the dissolved materials as nitrate salts.     

荧光分光光度法测定阿司匹林中游离水杨酸——PEG 1500-OP-(NH4)2SO4-H2O双水相体系萃取分离

提出了由聚乙二醇(PEG) 1500-OP-(NH,4),2SO,4 及少量水组成的双水相萃取体系并应用于从阿司匹林基体中萃取游离水杨酸.对试验条件作了系统试验,取得如下优化条件:① PEG1500(500 g·L-1)溶液及 OP(500 g·L-1)溶液的体积(mL)比为PEG:OP=2.50:1.50;②固体(NH,4),2SO,4-H,2O的加入量为 2.0 g;③加入 pH 6.0 的 B-R 缓冲溶液至总体积约为 10 mL.按此条件测得水杨酸的萃取率为 98.6%.萃取后,将上层液(即表面活性剂相)移至 10 mL 容量瓶中,加B-R 缓冲溶液至 10.0 mL,在λ,ex为305 nm,λ,em为 392 nm 波长条件下测定溶液的荧光强度.应用此方法分析了3件阿司匹林试样,每一个试样分析 10 次,所得结果的相对标准偏差(n=10)在1.7%～2.1%之间.在此样品的基础上加入水杨酸标准溶液进行回收率试验,所测得回收率在93.3%～103.3%之间,其相对标准偏差(n=5)≤2.5%.     

Extraction and spectrophotometric determination of gallium with 4-(2-pyridylazo)resorcinol

A sensitive and selective spectrophotometric determination of gallium is described. It is based on extraction of gallium from 3 M hydrochloric acid solution as a chloro-complex into 1,2-dichlorobenzene and exchange of the chloro ligand with 4-(2-pyridylazo)resorcinol (PAR); the final association complex of Ga—PAR with tetraphenylarsonium ions is measured in the organic phase. The absorption maximum occurs at 510 nm and the effective molar absorptivity is (8.2 ±0.3) ·1O⁴ l mol^-1cm^-1. Beer's law is obeyed over the range 0.2–2 p.p.m. of gallium. Few ions interfere.