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.     

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…     

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。     

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     

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。     

CONTENTS OF VOLUME 4 February 1995 Volume 4 Number 1

E伍壮ofmoboproatrontheCu（。baserlcatalystS、……··、…‘、….、.、。。…ChuW;etwR;Ktellnemenn,A.iXmlluG.X（l）WandevlOPmCnOfuelalcohoSynthesisfiDI’1syngas….。…..Chen.ZH;WYQ;UYibo,NL..BO,L.H;DUMX;hengG.口.;dJ.C.（！2）Cdcuhooonmethdmethdofcnectlveness日初见brD问卜if’earp】ed’--------ORpo…。。…….。…….、….、….,….、…。,、..、…、……..uL.（23）EffixtoftwratUreonloweralcoholSynthesisovermoifiedCu-Zncatalysts.、…………..、…。、。,….、…….。。口JJY。Zhu,口.M（…     

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.     

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.     

Crystal Structure of 3, 4-trans-4, 5-trans-2-Amino-3-cyano-1, 3-diethyloxy carbonyl- 4, 5-di (4-chlorophenyl)cyclopentene

1INTRoDUCT1oNThechemistriesofsamariumdiiodideandlow-valenttitaniumareofcurrentin--.terestinorganicSynthesis.Theyhavebeenwidelyusedinsyntheticreactions(l.2i.Thereactivityofthereagentstowardsvariousnitrogen-containingcomPOundshasal-readybeenexamined.Thereare,toourknowledge,noliteratureexamplesforthereductionofafylidenecyanoacetatederivativeswiththesereagents.Recently,wefoundthatthetitlecompoundisobtainedbycyclodimerizationreactionofpchlorObenzylidenecyanoacetatewithsamariumdiiodideorlow-va…     

Structure of BaGd2（MoO4）4 Crystal

The title compound belongs to monoclinic,space group C2/c with a=5.2694(1),b=12.6659(4),c=19.4108(2) ,β=91.504(2)°,V=1295.06(5) 3,Z=4 and Dc=5.599 g/cm3. The structure of BaGd2(MoO4)4 contains a MoO4 tetrahedron,a distorted GdO8 polyhedron,and Ba2+ ions in a tenfold coordination. The GdO8 polyhedra are linked together through edge-sharing to give a two-dimensional Gd layer. The MoO4 tetrahedra connected to the Gd atoms are capped up and down the Gd layer through common oxygen apices,thus forming a new Gd-Mo layer. Finally,the Gd-Mo layers are held together through bridging BaO10 polyhedra to form a three-dimensional framework. Since the Ba-μ3-O bond has a large average distance of 2.888 ,this structural characteristic will result in a cleavage along the (001) plane.     

LiF-K2WO4-BaWO4-CaWO4 four-component system

The LiF-K₂WO₄-BaWO₄-CaWO₄ four-component system was studied by physicochemical methods. A priori prediction of the phase composition of this system revealed its phase tree and crystallization tree, which were experimentally verified by topological modeling of the phase diagram. Equations of the general liquidus formation law were used to verify the validity and adequacy of the geometrical liquidus model. The density and electrical conductivity of a eutectic alloy sample of the title system were studied experimentally.     

Synthesis of 4H-1,3-benzoxazin-4-onium salts and 4-H-1,3-benzoxazin-4-ones

Salicylamide and its substituted derivatives react with aliphatic carboxylic acid anhydrides and perchloric acid to give 4H-1,3-benzoxazin-4-onium salts. These same compounds were obtained by acidic cyclization of O- and N-acylsalicylamides. The synthesized salts are converted to 2-substituted 4H-1,3-benzoxazin-4-ones by the action of triethylamine and are hydrolyzed by water to N-acylsalicylamides. The probable reaction scheme is examined.     

Fluorination of 4-nitroisoxazoline salts. Synthesis of 4-fluoro-4-nitroisoxazolines and 4-fluoroisoxazoles

Methods for the synthesis of hitherto unknown 4-fluoro-4-nitroisoxazolines by fluorination of 4-nitroisoxazoline salts with FClO₃ in MeOH and 4-fluoroisoxazoles by treatment of fluoronitroisoxazolines bearing the hydrogen atom bound to the C(5) atom of the isoxazole ring with MeONa in MeOH were developed.     

Synthesis of Cytotoxic 4-Sulfonyl-, 4-Sulfonylthio-and 4-Sulfothioazetidinones-2

4-Sulfonylazetidinones-2 were synthesized by the reaction of DBU and organic halides on the esters of penicillin sulfones. 4-Sulfonylthio- and 4-sulfothioazetindinones-2 were synthesized by nucleophilic substitution of the 2-benzothiazolylthio groups in 4-(benzothiazolylthio)azetidinones-2 using sodium sulfinates or sodium hydrogen sulfite. A study of their cytotoxic activities revealed the anticancer effect of compounds containing methylsulfonylthio-, 4-tolylsulfonylthio-, and 4-methoxycarbonylamino-phenylsulfonylthio-substituents at position 4 of the -lactam ring relative to a wide range of monolayer cultures of cancer cells in vitro.     

Solid-phase combinatorial syntheses of mesomorphic 4-alkoxyphenyl 4-alkoxybenzoylaminobenzoates

Eighteen two-ring and 100 three-ring benzenoid amides were synthesised using a solid-phase combinatorial method involving acylation or benzoylation and palladium(0)-catalysed carbonylation of a secondary amine, obtained by the reductive amination of 4-iodoaniline and a backbone amide linker. The purity of the products obtained was high enough for investigation of their thermal properties. All the three-ring derivatives were shown to be mesomorphic, but the two-ring derivatives were not. The mesomorphic behaviour and the transition temperatures of the three-ring derivatives were virtually identical to those of samples obtained by liquid-phase synthesis and purified by column chromatography and recrystallisation.     

Stereoselective epoxidation of 4-fluoro-4-nitrocyclohexenes

Novel fluorinated α-epoxycyclohexanes were synthesized in up to 96% yields by epoxidation of the Diels–Alder adducts of β-fluoro-β-nitrostyrenes and 2,3-dimethylbuta-1,3-diene. The epoxidation with m-chloroperoxybenzoic acid and subsequent hydrolysis into diols were found to proceed in a highly stereoselective manner.     

1, 4-氧硫杂萘-4, 4-二氧化物含氟衍生物的合成

以含氟的2-(2-氯-4-硝基苯磺酰基)-1-芳基乙酮为原料, 在K2CO3/TEBA/DMF体系中, 与烷基化试剂发生烷基化-环化反应。合成六种未经文献报道的1, 4-氧硫杂萘-4, 4-二氧化物的含氟衍生物,利用元素分析、IR、1H NMR、MS对其结构进行了表征。     

Synthesis and mesomorphic properties of 4-cyanophenyl and 4-nitrophenyl 4- n -alkoxytetrafluorobiphenyl-4'-carboxylates

Four homologous series of 4-cyanophenyl and 4-nitrophenyl 4- n -alkoxytetrafluorobiphenyl-4'carboxylates have been synthesized. Their mesomorphic properties were measured by polarizing optical microscopy and differential scanning calorimetry. The relationship between the properties and chemical structures of these compounds has been studied; the effects of terminal alkoxy chain length, polarizable end groups and the position of tetrafluorophenylene in the rigid core on mesomorphic behaviour are discussed in detail.     

A C4N4 Diaminopyrimidine Fluorophore

A new scaffold for producing efficient organic fluorescent materials was identified: 2,5-diamino-4,6-diarylpyrimidine featuring a C4N4 elemental composition. Single-step installation of two aryl groups at the 4,6-positions of the pyrimidine core delivered fluorescent organic materials in a modular fashion. A range of fluorescent compounds with distinct absorption/emission properties was readily accessed by changing the aromatic attachments. A generally high absorption coefficient and quantum yield were observed, including C4N4 derivatives that could fluoresce even in the solid state. The two amino groups at the 2,5-positions of the pyrimidine were essential for intense fluorescence with a large Stokes shift, which was corroborated by structural relaxation to a p-iminoquinone-like structure in the excited state. Besides live-cell imaging capabilities, fluorescent labeling of a protein involved in autophagy elucidated a new protein–protein interaction, supporting potential utility in bioimaging applications.     

4-乙酰氨基-4’-甲基丙烯酰氨基-二苯基甲烷的合成及其聚合

N-芳基丙烯酰胺是-类功能性单体,它能与丙烯酸酯类单体进行自由基共聚合。本文以4,4'-二氨基二苯基甲烷为起始原料,合成了新的带有较长侧基的甲基丙烯酰胺类单体,即4-乙酰氨基-4'-甲基丙烯酰氨基-二苯基甲烷(AMDPM)。它能进行自由基聚合或与丙烯酸甲酯(MA)共聚合。