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     

4，4＇－二氯二苯砜部分水解制取4－氯－4＇－羟基二苯砜

用高效液相色谱法（ＨＰＬＣ）对４，４＇－二氯二苯砜（双氯），４，４＇二羟基二苯砜（双酚）及４－氯－４＇－羧基二苯砜（单酚）进行了完全的分离，研究双氯部分水解制单酚发现，ＮａＯＨ用量越大、反应温度越高，水解速度越快，极值产率却越低；副产物双酚的含量随着反应时间增加，超过极值单酚产率后，由于副产物的增加，产率相对降低。最佳水解条件为水解温度１３５～１４０℃，ＮａＯＨ／双氯（摩尔比）为３．２５∶１，水解时间２．５～３小时，产率９０％以上。另外，还对水解过程中的缩聚现象及产物的纯化条件进行了讨论。     

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）…     

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…     

Synthesis and mesomorphic properties of 4-(4-bromopropyloxy)-4’-(4-alkyloxybenzylidene)anilines

This article describes the preparation and liquid crystalline properties of a new homologous series of 4-（4-bromopropyloxy）-4’- （4-alkyloxybenzylidene）anilines in which the phenyl ring is armed by a bromopropyloxy chain.The thermal behavior and mesomorphic properties of the synthesized compounds were studied with particular attention given to the correlation between their phase transition temperatures and anisotropic change influenced by molecular structure.All the members displayed enantiotropic smectic phase except for the homologue with the longest alkyloxy chain(R = C₁₈H₃₇),exhibiting only monotropic characteristic. The presence of bromine atom from the propyloxy side chain is found to be capable of altering and influencing the mesomorphic properties.     

CRYSTAL STRUCTURE OF Fe4S4[SC（CH3）3]4[（C4H9）4N]2

<正> Fe_4S_4[SC(CH_3)_3]_4[(C1H_9)_2,Mr=1193. 23,tetragonal,142d,a = 23. 272(2), c= 13. 080(5) A ,V=7084(3) A3,Z=4,DC=1. 12g·cm-3,UUUU(MoKa) = 10. 8cm-1,F(000) = 2568,R=0. 058 for 1005 observed reflections. The cluster anion contains a cubane-type Fe4S4 core compressed along the 4 axis which is crystallographically imposed. Compared to other salts with different cations ,the core is subject to slight structural distortions in different crystalline environments and crystallographic symmetry of the anion is related to that of the cation.     

溶胶-凝胶法合成Li_4SiO_4

Li4SiO4具有有利于离子传导的结构,为锂离子导体理想的基质材料[1].在硅酸盐体系中,硅的聚合态很复杂,难以得到纯相,鉴于固相法操作简单,在已有的文献中,合成方法多为固相法,但固相法不易保证成份的准确性、均匀性且合成温度较高.溶胶-凝胶法是近几年来发展起来的湿化学合成方法,用此法合成离子导体具有纯度高、均匀性好、颗粒小、反应过程易于控制等优点[2],而通常的溶胶-凝胶法是用金属醇盐与有机盐为前驱物,这样成本较高,且易造成污染.本文用金属醇盐及无机盐为前驱物,用溶胶-凝胶法合成了Li4SiO4纯相,并同一般固相法相比较,对合成的…     

4β-氨基-4脱氧鬼臼毒素和4β-氨基-4脱氧-4'-去甲基鬼臼毒素的两种新合成方法

我们在研究抗肿瘤活性物质的基础上[1～ 5 ],注意到鬼臼类化合物具有抗癌活性 ,但其毒副作用较大 ,我们对其结构进行了改造 ,以研制活性更高而毒性更小的新的衍生物 .从以前有关鬼臼毒素及其类似物的构效关系研究中已得出以下几个方面的结构要求是保持其抗癌活性必须具备的条件 :(ａ)在4’ 位有一个酚羟基 ;(ｂ)Ｃ 4取代基位是 β构型 ;(ｃ)具有反式内酯环[6 ].研究表明 ,4 β 酰胺基的鬼臼衍生物具有较强的抗癌活性[7].而 4 β 氨基 4脱氧鬼臼毒素和 4 β 氨基 4脱氧 4’去甲基鬼臼毒素是合成此类衍生物的最重要中间体 .合成这两个化合物的…     

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.     

NH4VO3在NH4H2PO4-H2O和(NH4)3PO4-H2O体系中的溶解度

采用等温溶解法测定了偏钒酸铵(NH₄VO₃)在NH₄H₂PO₄-H₂O和(NH₄)₃PO₄-H₂O体系中T = 298.15-328.15 K时的溶解度以及溶液的密度和pH值。结果表明, NH₄VO₃的溶解度随着(NH₄)₃PO₄或NH₄H₂PO₄溶液浓度的增大,先降低后升高,这是由于同离子效应、化学反应平衡及离子活度的共同作用。比较T = 298.15K时, NH₄VO₃分别在NH₄H₂PO₄-H₂O、(NH₄)₂HPO₄-H₂O和(NH₄)₃PO₄-H₂O体系中溶解度,发现在相同的磷酸盐浓度下, NH₄VO₃的溶解度在NH₄H₂PO₄-H₂O体系中最大,在(NH₄)₃PO₄-H₂O体系中居中,在(NH₄)₂HPO₄-H₂O体系中最小。进一步地,在T = 298.15 K和磷酸盐浓度C = 0.5 mol·kg^-1时,结合pH值和反应溶度积常数K_SP等计算三个体系中的平均离子活度系数(γ_±),发现γ_±值在(NH₄)₂HPO₄-H₂O体系中最大,在(NH₄)₃PO₄-H₂O体系中居中,在NH₄H₂PO₄-H₂O体系中最小,与溶解度规律一致。     

Structure ofp-tetrakis-(4-nitrophenylazo)calix[4]-arene-4-picoline (1∶4) complex

The structure of thep-tetrakis-(4-nitrophenylazo)calix[4]arene-4-picoline (14) complex has been determined by X-ray crystallography. Crystals are monoclinic, space groupC2/c,a=24.9097) Å,b=8.425(6) Å,c=33.81(1) Å, =101.13(2)°,D _c =1.330 g/cm³,Z=4, finalR value =0.067. The cone conformation adopted by this azocalixarene is disturbed by the positions of the picoline molecules. Two of them are inside the macorocycle cavity and the two others are outside. Supplementary Data relating to this article are deposited with the British Library as Supplementary Publication No. Sup. 82190 (32 pages).     

4-氯苯氧乙酸及4, 4′-bipy=4, 4′-联吡啶构筑的层状锌配合物的合成、晶体结构

水热条件下, 合成了一个新的锌(Ⅱ)配位聚合物[Zn(PCPA)₂(4, 4′-bipy)(H₂O)]_n(PCPA=4-氯苯氧乙酸, 4, 4′-bipy=4, 4′-联吡啶), 并通过元素分析、红外光谱、紫外光谱、热重分析、X-射线粉末衍射和X-射线单晶衍射对其进行了表征。锌(Ⅱ)分别与来自2个4, 4′-bipy的2个氮原子、3个4-氯苯氧乙酸的3个氧原子和1个水分子中的1个氧原子配位, 形成变形的八面体的配位构型。由于4-氯苯氧乙酸和4, 4′-bipy的桥联作用, 配合物在空间形成了二维层状结构, 在此二维层状结构中存在的O-H…O氢键起到了稳定结构的作用。     

Are the NF4+ cations in NF4BF4 really nontetrahedral?

The crystal structure of NF4BF4 has been reexamined. The low-temperature X-ray structure and solid-state 19F MAS NMR spectra are in agreement with the conclusions reached from the vibrational spectra, that solid NF4+ salts contain only tetrahedral NF4+ cations. The alleged observation of two kind of nontetrahedral NF4+ cations in several previous crystal structures is attributed to incorrectly solved structures and, possibly, problems caused by disorder or twinning. It is further evidence for the dangers of over-reliance on crystal structures. Flawed crystal structures can give rise to either bad or unwarranted theory.