Synthesis and Polymerization of Bismaleimide Derived from 5(6)-amino-1(4′-aminophenyl)-1,3,3′-trimethyl indane

The acid-catalyzed dimerization of α-methyl styrene led to the formation of trimethyl phenyl indane, which on nitration followed by reduction using hydrazine hydrate gave 5(6)-amino-1(4′-aminophenyl)-1,3,3′-trimethyl indane. This aromatic diamine was used to synthesize bismaleamic acid and imidized to yield bismaleimide. The bismaleamic acid was converted to prepolymer directly by imidizing it in refluxing toluene. All the materials synthesized were characterized using FTIR, ¹H and ¹³C NMR. The direct inlet mass spectral characterizations were carried out for bismaleamic acid, bismaleimide and bismaleimide prepolymer. The fragmentation pattern was discussed in detail and the structure proposed was confirmed. The thermogravimetric studies were done for all the materials and kinetic parameters (energy of activation and frequency factor) were calculated using Dharwadkar and Kharkhanavala method. The structural changes occurring in the thermally polymerized bismaleimide and bismaleimide prepolymer were discussed.     

Synthesis of soluble polyarylenes containing alternating 4,4′-(1,1′-binaphthyl) and 4,4′-(3,3′-diphenyl)biphenyl structural units

Summary The synthesis and Ni(0) catalyzed homocoupling polymerization of 4,4-bis[5-(trifluoromethanesulfonyloxy)-2-biphenylyl]-1, 1-binaphthyl (9) are described. This polymerization reaction produces a soluble polyarylene containing alternating 4,4-(1,1-binaphthyl) and 4,4-(3,3-diphenyl)biphenyl structural units.     

Coordination of cobalt(III), nickel(II), copper(II), palladium(II) and platinum(II) with N-ethyl-N′-(4′-methylthiazol-2′-yl)thiourea (HL)

Coordination complexes of formula [ML₂], [CoL₃], [Pd(HL)Cl₂], [CuLCl(H₂O)] and [CuL₂(H₂O)₂] {L=anion of N-ethyl-N^′-(4^′-methylthiazol-2′-yl)thiourea; M=Pt^II, Pd^II or Ni^II} were prepared and characterized by elemental analyses, magnetic susceptibilities, and by IR, NMR, electronic and mass spectral measurements.     

Antioxidant action of a lipophilic nitroxyl radical,cyclohexane-1-spiro-2′-(4′-oxyimidazolidine-1′-oxyl)-5′-spiro-1″-cyclohexane,against lipid peroxidation under hypoxic conditions

Nitroxyl radicals are known to act as radical scavenging antioxidants. In the present study, a lipophilic nitroxyl radical, cyclohexane-1-spiro-2′-(4′-oxyimidazolidine-1′-oxyl)-5′-spiro-1″-cyclohexane (nitroxyl radical I) was synthesized and its antioxidant capacity was assessed in comparison with a hydrophilic nitroxyl radical, 4-hydroxy-2,2,6,6-tetramethylpiperidine-N-oxyl (Tempol). Both nitroxyl radical I and Tempol inhibited methyl linoleate oxidation induced by free radicals, and the efficacy increased with decreasing partial pressure of oxygen, the effect being more pronounced for nitroxyl radical I than Tempol. Their hydroxylamines inhibited lipid peroxidation more effectively than their corresponding parent nitroxyl radicals. In liposomal membranes, a synergistic effect was observed in the combination of nitroxyl radical I with ascorbic acid, whereas only an additive effect was observed between Tempol and ascorbic acid. The present study suggests that nitroxyl radical I and its hydroxylamine may act as potent antioxidants, especially in combination with ascorbic acid under hypoxic conditions.     

4,4′-(4,4′-砜基二苯氧基)二苯甲酰氯(SODBC)的合成

以对甲基苯酚、4,4′-二氯二苯砜为原料,通过亲核取代反应合成了4,4′-二(4-甲基苯氧基)二苯砜,用高锰酸钾将甲基氧化得到4,4′-(4,4′-砜基二苯氧基)二苯甲酸(SODBA),后者在二氯亚砜和路易斯碱的催化下合成了4,4′-(4,4′-砜基二苯氧基)二苯甲酰氯(SODBC)白色固体.用FT-IR、1H-NMR、13C-NMR、DSC等对其进行了表征,实验证明该化合物具有预期的结构和较高的纯度.     

Syntheses and structures of cadmium(II) and cobalt(II) coordination polymers based on 1,1′-(2,2′-oxybis(ethane-2,1-diyl))bis(1H-imidazole) and carboxylate ligands

Two novel coordination polymers containing Cd(II) and Co(II) metals, connected via 1,1′-(2,2′-oxybis(ethane-2,1-diyl))bis(1H-imidazole) (L) ligand, have been synthesized. Compound [Cd(L)₂(p-BDC)] · 2H₂O (1) (p-BDC = 1,4-benzenedicarboxylate anion) is a three-dimensional interdigitated supramolecular architecture. Compound [Co(L)(BTCA)_0.5] (2) (BTCA = 1,2,3,4-butanetetracarboxylate anion) possesses a unique (3,4)-connected 3D framework with (8³)₂(8⁵ · 10) topology.     

Sulfate binding in zinc(II) complexes of a monopyridylurea ligand N-(1-naphthyl)-N′-(3-pyridyl)urea

Two zinc(II) complexes of a urea-functionalized pyridyl ligand, [Zn(SO₄)L₃]·CH₃OH (1) and {[Zn(μ₂-SO₄)L₂]·0.5CH₃OH}_n (2) (L = N-(1-naphthyl)-N′-(3-pyridyl)urea), have been synthesized by the reaction of L with ZnSO₄·7H₂O under different conditions. Complex 1 is a hydrogen-bonded 2D grid structure in which the sulfate anion not only coordinates to the Zn^II ion as a monodentate ligand but also forms multiple hydrogen bonds with the urea groups of adjacent molecules. In complex 2 the sulfate ion serves as a μ₂-bridging ligand, connecting the Zn^II ions to form an infinite 1D organic–inorganic hybrid framework. Meanwhile, the sulfate anion is also bound by neighboring ligands through hydrogen bonds between urea groups and the non-coordinated oxygen atoms. The solid-state emission spectra of 1 and 2 show a red shift of the fluorescence emission of ligand L.     

4,4′-二苯基甲烷二异氰酸酯(MDI)

生产现状:MDI是聚氨酯的主要原料之一,由于受世界性建筑优势的推动和纯MDI基料新用途的出现,MDI牛产获得了迅速发展。1987年世界生产能力为103.4万吨,其中北美40.5万吨、欧洲45.8万吨、亚洲10.9万吨、南美和东欧6.2万吨。1980年世界MDI产量为56.5万吨,1985年达86.6万吨,1980～1985     

炭92′论文题目(续2)

E15对氯化氰在W五e tlerite炭上分解的表面及气相 研究 N。5 .Melntyre等(够1)E17用气相生长带状石墨丝制备带有序尺寸和显微 结构的超细片状石墨 H。Murayama等(535)E一18用夹入硅酸盐或硅酸铝中把的芳香按正离子 合成石墨 B。Maitnoun等‘(538)P一E4催化剂引晶技术对气相生长炭纤雄形成的 影响 T。Kato等(541)P一ES用硝酸和氨改进活性炭 R。J。J。Jansen(544)P一E7热解炭涂层的烧损性质 E。W inkler等(547)P一ES若干沉积参数对热解炭电阻率的影响 W。Kant等临50)P一Eg甲烷热分解期间热解炭在镍粉和钻粉上的 生成 A .E.Kuguc…     

The unexpected synthesis of rhodium(I) complexes with the 1-(2′-pyridyl)-3-oxo-1-propenoxide anionic ligand

The enaminone compound 1-(2^′-pyridyl)-3-dimethylamine-1-propenone (1) reacts with [{Rh(μ-OY)(COD)}₂] (OY=OMe, OH) dimers in the presence of water to form a mononuclear square-planar rhodium(I) complex 2, which incorporates the unexpected 1-(2^′-pyridyl)-3-oxo-1-propenoxide ligand (N, O). The mediation of the metal in this ligand transformation is demonstrated. The crystal structure of [Rh(N,O)(COD)] (2) reveals the coordination of the new propenoxide ligand as a N,O-bidentate with the presence of an additional non-coordinated aldehyde group. Complex 2 reacts with CO by displacement of the COD molecule, but maintaining the N,O-coordination of the chelate propenoxide ligand.     

信息(1)

由轻工业陶瓷研究所承担的国家科技部项目《全国主要陶瓷矿产原材料资源数据库》已于 2 0 0 1年 1季度正式启动。该项目计划在二年的时间内通过对我国各省市已探明和开采的储量在 1 0 0万吨以上 ,年产值超过 50 0万元的矿产原材料资源现代性能数据的采集、样本测试分析 ,建立一个涉及日用陶瓷、建筑卫生陶瓷、特种陶瓷等行业、系统的、动态的、网络化的数据库。该数据库的建成可为广大陶瓷行业科技人员提供快速准确便捷的资源数据信息服务 ,有利于我国陶瓷矿产资源的保护和合理开发利用 ,将为我国陶瓷行业在 2 1世纪的结构调整、实现由大而…     

The electrochemical properties of polyaniline derivatives: poly(4,4′-diphenylamine methylenes) and poly(4,4′-diphenylimine methines)

Summary The electrochemical properties of poly(4,4-diphenylamine methylenes) and poly(4,4-diphenylimine methines) were investigated by cyclic voltammetry. A dehydrogenation reaction occured when poly(4,4-diphenylamine methylenes) underwent a electrochemical reaction and transformed to poly(4,4-diphenylimine methines). The fully oxidized poly(4,4-diphenylimine methines) had the electrochemical band gaps of 1.60–1.72 eV, which were found to significantly smaller than those of the fully reduced poly(4,4-diphenylamine methylenes).     

4,4′-双(4′-羟苯基)戊酸合成的研究

研究了以乙酰丙酸(LA)和苯酚为原料,盐酸为催化剂,巯基乙酸为助催化剂合成4,4’-双(4’-羟苯基)戊酸的工艺。考察了助催化剂种类及用量、反应物料配比、反应温度、反应时间和催化剂用量等因素的影响。通过正交试验,优化了合成工艺。试验表明:n(苯酚)∶n(LA)(摩尔比)=4∶1,反应温度60℃,反应时间为45 h,n(HCl)∶n(LA)=4∶1时,最高产率为97.1%。产物结构经红光外光谱、氢核磁谱进行了表征确定为4,4’-双(4’-羟苯基)戊酸。     

Synthesis,characterization, and platinum-catalyzed cross-linking of 1,4-bis(1-methyl-1-silacyclobutyl) benzene,co-oligo(1-silacyclobut-1-ylidene-1,4-phenylene), and co-oligo(1-silacyclobut-1-ylidene-4,4′-diphenylene)

1,4-bis(1-Methyl-1-silacyclobutyl)benzene (I) has been prepared by the reaction of 1-chloro-1-methyl-1-silacyclobutane with the di-Grignard reagent prepared fromp-dibromobenzene. In a similar manner, co-oligo(1-silacyclobut-1-ylidene-1,4-phenylene) (II) and co-oligo(1-silacyclobut-1-ylidene-4,4′-biphenylene) (III) have been prepared by condensation oligomerization between 1,1-dichloro-1-silacyclobutane and the di-Grignard reagents prepared fromp-dibromobenzene and 4,4′-dibromobiphenyl, respectively. These have been characterized by¹H,¹³C, and²⁹Si NMR as well as FT-IR and UV spectroscopy. The molecular weight distributions of these co-oligomers have been determined by GPC. Their thermal stabilities have been evaluated by TGA. Thermal degradation of these co-oligomers in nitrogen gives high (60%) char yields. The stability of these chars in air has been determined. TheT _g's of these co-oligomers have been measured by DSC. Platinum-catalyzed ring opening of the silacyclobutane rings ofI,II, andIII cross-links these to thermoset materials. The bending moduli (logE′), tan δ, andT _g's of these materials have been determined by DMTA. The dielectric constant and dissipation factor of cross-linkedII are reported.     

5,5′-偶氮双(1-甲氧基甲酰胺基四唑)的合成

5,5′-偶氮双(1-甲氧基甲酰胺基四唑)(ADMCAT)是制备高能含能化合物5,5￠-偶氮双(1-硝胺基四唑)ABNAT的关键中间体。以甲氧基甲酰肼和叠氮氰为原料,经加成、环化和偶氮化等反应合成ADMCAT,利用红外光谱、核磁(~1H-NMR、~(13)C-NMR)、元素分析等方法表征化合物结构,培养ADMCAT单晶,并对1-甲氧基甲酰基-1,5-二氨基四唑(MCDAT)和ADMCAT的热性能进行研究。晶体结构分析表明ADMCAT属单斜晶系,空间群为P2(1)/c,晶体学参数为:a为(0.989 5±0.000 8) nm,b为(0.593 4±0.000 5) nm,c为(1.146 7±0.000 9) nm,α为90°,β为(103.798±0.011)°,γ为90°,V为(0.653 9±0.000 9) nm3,Z为2,Dc为1.586 g×cm~(-3),μ为0.134 mm~(-1),F(000)为320。采用差示扫描量热(DSC)曲线分析表明,MCDAT和ADMCAT的热稳定性良好。     

第十届国际化学工程大会(CHISA′90)和第七届国际干燥会议(IDS′90)

CHISA是捷克语中“化学工程、化工装备设计与自动化”的简写,从1962年起每三年举行一次,地点均在捷克。该大会现己成为世界性的最重要和规模最大的化学工程大会之一。本届大会参加者来自51个国家和地区,共1600余人。会议共提交论文1400     

Non-isothermal degradation kinetics of poly (2,2′-dihydroxybiphenyl)

Catalytic oxidative polymerization of 2,2′-dihydroxybiphenyl (DHBP) was performed by using Schiff base polymer-Cu (II) complex and hydrogen peroxide as catalyst and oxidant, respectively. According to size exclusion chromatography (SEC) analysis, the number-average molecular weight (M _n), weight-average molecular weight (M _w) and polydispersity index (PDI) values of poly (2,2′-dihydroxybiphenyl) (PDHBP) were found to be 37,500, 90,000 g mol⁻¹ and 2.4, respectively. The thermal degradation kinetics was investigated by thermogravimetric analysis in dynamic nitrogen atmosphere at four different heating rates: 5, 10, 15 and 20 °C min⁻¹. The derivative thermogravimetry curves of PDHBP showed that its thermal degradation process had one weight-loss step. The apparent activation energies of thermal decomposition for PDHBP as determined by Tang, Flynn–Wall–Ozawa (FWO), Kissenger–Akahira–Sunose (KAS), Coats–Redfern (CR) and Invariant kinetic parameter (IKP) methods were 109.1, 109.0, 110.0, 108.4 and 109.8 kJ mol⁻¹, respectively. The mechanism function and pre-exponential factor were determined by master plots and Criado–Malek–Ortega method. The most likely decomposition process was a D _n Deceleration type in terms of the CR, master plots and Criado–Malek–Ortega results.     

1,3-二(3′-溴苯基)-5-(4′-氯苯基)苯的合成

以苯乙酮、溴素为原料 ,无水三氯化铝为催化剂 ,按n (苯乙酮 )∶n (溴素 )∶n (AlCl3) =1.8∶2 .3∶4.2制得间溴苯乙酮 ,产率为 6 5 % ;间溴苯乙酮与催化剂四氯化硅按n(间溴苯乙酮 )∶n(四氯化硅 ) =1∶1在无水乙醇中经缩合反应制得 1,3 二 (3′ 溴苯基 )丁烯 2 酮 1(A) ,产率为5 2 % ,以此为中间体与对氯苯乙酮在四氯化硅催化下按n(A)∶n (对氯苯乙酮 )∶n (四氯化硅 )=1.0∶1.0∶2 .5经缩合反应 ,合成了 1,3 二 (3′ 溴苯基 ) 5 (4′ 氯苯基 )苯 (B) ,产率为 43%。     

Two-dimensional cobalt-bipyridinedicarboxylate coordination polymer: [Co(2,2′-bipyridine-5,5′-dicarboxylato) (H2O)]·(H2O)

Hydrothermal reaction between cobalt(II) nitrate and 2,2^′-bipyridine-5,5^′-dicarboxylic acid in the presence of NaOAc gave a two-dimensional coordination-polymer of cobalt(II), [Co(2,2^′-bipyridine-5,5^′-dicarboxylato)(H₂O)]·(H₂O) (1). X-ray structure determination showed that compound 1 has a two-dimensional infinite network based on cobalt-bipyridinedicarboxylate building blocks and has a relatively small channel of 5.0×6.6 Å.