不同制法镁铝尖晶石在环已酮双聚中的应用

用共沉淀法，溶胶－凝胶法，超临界干燥技术和脲燃烧法制备了一系列镁铝尖晶石，并将其用于环已酮双聚合成环已烯环已酮（ＣＨＣＨ）的反应中。借助于ＴＥＭ、ＸＲＤ、ＢＥＴ和ＣＯ２－ＴＰＤ等手段考察了不同制备方法对催化剂性质及性能的影响。     

不同制法镁铝尖晶石在环己酮双聚中的应用

用共沉淀法，溶胶－凝胶法，超临界干燥技术和脲燃烧法制备了一系列镁铝尖晶石，并将其用于环己酮双聚合成环己烯环己酮（ＣＨＣＨ）的反应中。借助于ＴＥＭ、ＸＲＤ、ＢＥＴ和ＣＯ＿２－ＴＰＤ等手段考察了不同制备方法对催化剂性质及性能的影响。     

联氨在d—过渡金属配合物的MTP（о—NO2）TBP修饰石墨电…

研究了Ｎ２Ｈ４在间－四（邻－硝基苯基）四苯并卟啉铁（Ⅲ）、钴（Ⅱ）、锌（Ⅱ）和镍（Ⅱ）配合物［ＭＴＰ（о－ＮＯ２）ＴＢＰ，简称ＭＴＢＰ］修饰石墨电极上的催化电氧化反应，测得该系列金属四苯并卟啉的催化活性的顺序为Ｃｏ（Ⅱ）ＴＢＰ＞ＣｌＦｅ（Ⅲ）ＴＢＰ＞Ｎｉ（Ⅱ）ＴＢＰ＞Ｚｎ（Ⅱ）ＴＢＰ≈石墨，考察了Ｃｏ（Ⅱ）ＴＢＰ和ＣｌＦｅ（Ⅲ）ＴＢＰ催化联氨电氧化反应的动力学过程。结果表明，ＯＨ＾－和Ｎ２Ｈ４在Ｃ     

金属基上以YSZ为过渡层的YBCO薄膜的微观结构

采用透射电子显微术（ＴＥＭ），研究了用磁控溅射技术在柔性金属基体上制备的、钇稳定的ＺｒＯ２（ＹＳＺ）为过镀层的ＹＢａ２Ｃｕ３Ｏ７－ｙ（ＹＢＣＯ）薄膜的横断面结构。所得ＹＢＣＯ膜的超导临界转变温度Ｔｃ为９１Ｋ，临界电流密度Ｊｃ＝２×１０３Ａ／ｃｍ２（７７Ｋ，０Ｔ）。基体为Ｎｉ基合金（ＨａｓｔｅｌｏｙＣ）。ＹＳＺ层为致密、均匀的细晶组织，约１２μｍ厚，具有织构取向，并与基体紧密连接。ＹＢＣＯ层的厚度不均匀，约５００ｎｍ；ＹＢＣＯ／ＹＳＺ界面有时连接较差，在该界面上有杂质出现，杂质有可能引发裂纹。     

基于甲基丙烯酸（9蒽）甲基酯共聚物为敏感膜的土霉素荧光光纤传感器

将甲基丙烯酸（９蒽）甲基酯与甲基丙烯酸甲酯和丙烯酸乙酯共聚，制备了一种具有荧光的共聚物（ＰＡＭＢ）并基于土霉素（ＯＴＣ）对ＰＡＭＢ共聚物荧光的可逆熄灭作用，研制了一种测定ＯＴＣ的荧光光纤传感器，该传感器对ＯＴＣ的响应具有好的稳定性和可逆性。响应时间和回复时间均小于３０ｓ，在２．０×１０＾－７～２．０×１０＾－４ｍｏｌ／ＬＯＴＣ浓度范围内有良好的线性关系，碱金属，碱土金属离子及常用药物对ＯＴＣ测定没     

微生物脱硫过程中的产物分析

ｌ 引 言微生物脱除矿物燃料中的杂环有机硫分为微生物降解脱硫和微生物催化脱硫，前一途径中菌株通过断裂有机化合物的Ｃ－Ｃ键，降解模型化合物二苯并噻吩（ＤＢＴ）生成含硫水溶性产物从燃料中脱除，破坏了碳氢化合物的碳骨架，引起燃烧值的降低。后一途径中微生物或它们的酶催化氧化ＤＢＴ的杂环硫原子，生成二苯并噻吩砜（ＤＢＴＯ２）及终产物 ２－羟基联苯（ＨＢＰ）和硫酸盐（‘４Ｓ’途径），保留了整个碳氢化合物的骨架。本研究用ＤＢＴ作为唯一硫源筛选不同菌种，通过液相色谱（ＨＰＬＣ）和液相色谱／质叙质谱联用（ＬＣ／ＭＳ…     

镨－三溴偶氮胂络合比和稳定常数双系列线性回归法测定

以双系列线性回归法在显色剂准确浓度未知的情况下研究了Ｐｒ￣（３＋）与三溴偶氮肿（ＴＢＡ）的络合反应。在１２ｍｏｌ／Ｌ的ＨＣＩ介质中，侧得Ｐｒ￣（３＋）与ＴＢＡ形成１：３的络合物，条件稳定常数ｌｇβ＿３＝１５４７，摩尔吸光系数．     

丁基罗丹明B.四溴荧光素双荧光剂萃取荧光法测定镓

１引言本文在选择性、灵敏度较高的丁基罗丹明Ｂ（ＢＲＢ）甲苯萃取荧光法测定镓的基础上，调ｐＨ值使ＧａＣｌ４ＢＲＢ三元络合物解析，ＢＲＢ进入水相。加入与ＢＲＢ颜色相近的四溴荧光素（ＴＢＦ），形成的ＢＲＢ２·ＴＢＦ再被甲苯萃取，萃取液中加入等体积正丁醇后进行测定。由于离子对（ＢＲＢ２·ＴＢＦ）中双荧光剂的叠加效应，使方法具有较高的灵敏度，检出限由原方法的０．３μｇ／Ｌ降为０．１μｇ／Ｌ，用于矿样中镓的测定，结果满意。２实验部分２．１仪器与试剂岛津ＲＦ－５４０荧光分光光度计；ｐＨＳ－３Ｃ型精密ｐＨ计（上…     

分子晶体中的几种分子间相互作用

描述了ＨＥＫ－ＤＤＱ，（Ｃｏ（Ｃ５Ｈ５）２（Ｎｉ（ｄｍｉｔ）２）ＢＢＢＴ－ＤＴＴ三个晶体结构中的π．．．π，Ｓ．．．Ｓ；Ｂｒ．．．Ｂｒ分子间相互作用，讨论了分子晶体中的分子间相线作用的材料化学意义。     

脑显像剂~（99m）Tc－ECD的制备研究

~（９９ｍ）Ｔｃ－ＥＣＤ是目前脑显像剂中一种较为理想的放射性诊断药物。本文介绍了从基本原料（Ｌ）半胱氨酸开始合成配体ＥＣＤ（Ｎ，Ｎ＇－乙撑－双－Ｌ半胱氨酸乙酯），采用锡作还原剂实现了一步法~（９９ｍ）Ｔｃ标记ＥＣＤ，并对制备的~（９９ｍ）Ｔｃ－ＥＣＤ进行了初步动物实验以评价其生物学性能。     

New developments and directions in the area of elastomers and rubberlike elasticity

There are number of important developments in the area of elastomeric polymers, including (i) network chains of controlled stiffness, (ii) model elastomers (including dangling-chain networks), (iii) fluorosiloxane elastomers, (iv) new thermoplastic elastomers, (v) other new elastomers, (v) bimodal network chain-length distributions, (vi) cross linking in solution or in a state of deformation, and (vii) gel collapse. Interesting elastomeric composites include those with (i) in-situ generated ceramic-like particles, (ii) ellipsoidal fillers, (iii) clay-like layered fillers, (iv) polyhedral oligomeric silsesquioxane (POSS) particles, (v) porous fillers, (vi) elastomeric domains modifying ceramics, and (vii) controlled interfaces. New characterization techniques are being developed for elastomers, and there have been new developments in elasticity theory and in elastomer processing. Some examples of societal aspects of relevance are (i) synthesis of elastomers in environmentally-friendly solvents, (ii) biosynthesis, (iii), recyclability, (iv) improved adhesion to tire cords, and (v) better barrier properties in anti-terrorism clothing. Educational topics include curriculum development, and mobile laboratories for elastomer experiments and demonstrations.     

N,N'-ethylenebis(pyridoxylideneiminato) and N,N'-ethylenebis(pyridoxylaminato): synthesis, characterization, potentiometric, spectroscopic, and DFT studies of their vanadium(IV) and vanadium(V) complexes

The Schiff base N,N'-ethylenebis(pyridoxylideneiminato) (H(2)pyr(2)en, 1) was synthesized by reaction of pyridoxal with ethylenediamine; reduction of H(2)pyr(2)en with NaBH(4) yielded the reduced Schiff base N,N'-ethylenebis(pyridoxylaminato) (H(2)Rpyr(2)en, 2); their crystal structures were determined by X-ray diffraction. The totally protonated forms of 1 and 2 correspond to H(6)L(4+), and all protonation constants were determined by pH-potentiometric and (1)H NMR titrations. Several vanadium(IV) and vanadium(V) complexes of these and other related ligands were prepared and characterized in solution and in the solid state. The X-ray crystal structure of [V(V)O(2)(HRpyr(2)en)] shows the metal in a distorted octahedral geometry, with the ligand coordinated through the N-amine and O-phenolato moieties, with one of the pyridine-N atoms protonated. Crystals of [(V(V)O(2))(2)(pyren)(2)].2 H(2)O were obtained from solutions containing H(2)pyr(2)en and oxovanadium(IV), where Hpyren is the "half" Schiff base of pyridoxal and ethylenediamine. The complexation of V(IV)O(2+) and V(V)O(2) (+) with H(2)pyr(2)en, H(2)Rpyr(2)en and pyridoxamine in aqueous solution were studied by pH-potentiometry, UV/Vis absorption spectrophotometry, as well as by EPR spectroscopy for the V(IV)O systems and (1)H and (51)V NMR spectroscopy for the V(V)O(2) systems. Very significant differences in the metal-binding abilities of the ligands were found. Both 1 and 2 act as tetradentate ligands. H(2)Rpyr(2)en is stable to hydrolysis and several isomers form in solution, namely cis-trans type complexes with V(IV)O, and alpha-cis- and beta-cis-type complexes with V(V)O(2). The pyridinium-N atoms of the pyridoxal rings do not take part in the coordination but are involved in acid-base reactions that affect the number, type, and relative amount of the isomers of the V(IV)O-H(2)Rpyr(2)en and V(V)O(2)-H(2)Rpyr(2)en complexes present in solution. DFT calculations were carried out and support the formation and identification of the isomers detected by EPR or NMR spectroscopy, and the strong equatorial and axial binding of the O-phenolato in V(IV)O and V(V)O(2) complexes. Moreover, the DFT calculations done for the [V(IV)O(H(2)Rpyr(2)en)] system indicate that for almost all complexes the presence of a sixth equatorial or axial H(2)O ligand leads to much more stable compounds.     

Simple organofluorine compounds giving field-dependent 13C and 19F NMR spectra with complex patterns: higher order effects and cross-correlated relaxation

The CF(3) signals in the (13)C{(1)H} spectrum of 1,1,1,3,3,3-hexafluoroisopropyl alcohol and the (CF(3))(2) CH signals in the corresponding triflate exhibit much greater complexity than might first be expected. The same holds for the (13)C satellites in the (19)F spectra. Complex patterns appear because of higher order effects resulting from the combination of a relatively large four-bond (19)F-(19)F J coupling in the ((13)CF(3))(12)CH((12)CF(3))-containing isotopomer and a typical large one-bond (13)C/(12)C isotope effect on the (19)F chemical shift. This complexity cannot be eliminated at very high magnetic field strengths. The triflate (CF(3))(2)CH-O-SO(2)CF(3) presents still additional complexity because of the presence of two different types of CF(3) groups exhibiting (6)J(FF) in any of the isotopomers and the chemical shift differences in hertz between the various (19)F signals in the two different (13)CF(3)-containing isotopomers. In addition, the presence of a small (5)J(CF) in the ((13)CF(3))((12)CF(3))(12)CH-O-SO(2) (12)CF(3) isotopomer is revealed only through simulations. The hexafluoroisopropyl CF(3) groups in the alcohol and triflate and the SO(2)CF(3) group in the triflate apparently provide the first examples of cross-correlated relaxation in (13)CF(3) groups. An analysis of the spectra in the context of previously reported work highlights the novel aspects of our findings. In particular, for each part of the complex hexafluoroisopropyl CF(3) quartet, peak height and linewidth variations resulting from cross-correlated relaxation are observed. These variations within a group of (13)C signals reflect different spin-lattice and spin-spin relaxation rates for the transitions within that group arising from higher order coupling effects.     

A feasibility study on the use of Li(4)V(3)O(8) as a high capacity cathode material for lithium-ion batteries

Li(4)V(3)O(8) materials have been prepared by chemical lithiation by Li(2)S of spherical Li(1.1)V(3)O(8) precursor materials obtained by a spray-drying technique. The over-lithiated vanadates were characterised physically by using scanning electron microscopy (SEM) and X-ray diffraction (XRD), and electrochemically using galvanostatic charge-discharge and cyclic voltammetry measurements in both the half-cell (vs. Li metal) and full-cell (vs. graphite) systems. The Li(4)V(3)O(8) materials are stable in air for up to 5 h, with almost no capacity drop for the samples stored under air. However, prolonged exposure to air will severely change the composition of the Li(4)V(3)O(8) materials, resulting in both Li(1.1)V(3)O(8) and Li(2)CO(3). The electrochemical performance of these over-lithiated vanadates was found to be very sensitive to the conductive additive (carbon black) content in the cathode. When sufficient carbon black is added, the Li(4)V(3)O(8) cathode exhibits good cycling behaviour and excellent rate capabilities, matching those of the Li(1.1)V(3)O(8) precursor material, that is, retaining an average charge capacity of 205 mAh g(-1) at 2800 mA g(-1) (8C rate; 1C rate means full charge or discharge of a battery in one hour), when cycled in the potential range of 2.0-4.0 V versus Li metal. When applied in a non-optimised full cell system (vs. graphite), the Li(4)V(3)O(8) cathode showed promising cycling behaviour, retaining a charge capacity (Li(+) extraction) above 130 mAh g(-1) beyond 50 cycles, when cycled in the voltage range of 1.6-4.0 V, at a specific current of 117 mA g(-1) (C/3 rate).     

苯甲醛在离子液体中的电化学行为

应用线性扫描循环伏安法、方波循环伏安法和计时电量法测定苯甲醛在3种离子液体C4M IMBF4、C6M IMBF4和C8M IMBF4中的电化学行为.实验表明,在C4M IIVIBF4离子液体中苯甲醛于GC电极上的还原包含两个连续、不可逆单电子过程,对应的方波I~E曲线峰电位Ep为-1.39 V和-1.69 V,估算的扩散系数分别为D1=1.5×10-8cm2/s和D2=1.3×10-8cm2/s.而在C6M IMBF4和C8M IMBF4离子液体中,则苯甲醛于GC电极仅显示一个电流峰,这可能是因为C4M IMBF4的碱性较C6M IMBF4和C8M IMBF4弱的缘故;而电流的衰减时间亦依C4M IMBF4,C6M IMBF4,C8M IMBF4,次序增长,并会导致更慢的异相动力学过程.     

Synthesis of phthalide derivatives using nickel-catalyzed cyclization of o-haloesters with aldehydes

The reaction of o-bromobenzoate (1 b) with benzaldehyde (2 a) in the presence of [NiBr(2)(dppe)] (dppe=1,2-bis(diphenylphosphino)ethane) and zinc powder in THF (24 hours, reflux temperature), afforded 3-phenyl-3H-isobenzofuran-1-one (3 a) in an 86 % yield. Similarly, o-iodobenzoate reacts with 2 a to give 3 a, but in a lower yield (50 %). A series of substituted aromatic and aliphatic aldehydes (2 b, 4-MeC(6)H(4)CHO; 2 c, 4-MeOC(6)H(4)CHO; 2 d, 3-MeOC(6)H(4)CHO; 2 e, 2-MeOC(6)H(4)CHO; 2 f, 4-CNC(6)H(4)CHO; 2 g, 4-(Me)(3)CC(6)H(4)CHO; 2 h, 4-C(6)H(5)C(6)H(4)CHO; 2 i, 4-ClC(6)H(4)CHO; 2 j, 4-CF(3)C(6)H(4)CHO; 2 k, CH(3)(CH(2))(5)CHO; 2 l, CH(3)(CH(2))(2)CHO) also underwent cyclization with o-bromobenzoate (1 b) producing the corresponding phthalide derivatives in moderate to excellent yields and with high chemoselectivity. Like 1 b, methyl 2-bromo-4,5-dimethoxybenzoate (1 c) reacts with tolualdehyde (2 b) to give the corresponding substituted phthalide 3 m in a 71 % yield. The methodology can be further applied to the synthesis of six-membered lactones. The reaction of methyl 2-(2-bromophenyl)acetate (1 d) with benzaldehyde under similar reaction conditions afforded six-membered lactone 3 o in a 68 % yield. A possible catalytic mechanism for this cyclization is also proposed.     

New highly stable metallabenzenes via nucleophilic aromatic substitution reaction

Treatment of the ruthenabenzene [Ru{CHC(PPh(3))CHC(PPh(3))CH}Cl(2)(PPh(3))(2)]Cl (1) with excess 8-hydroxyquinoline in the presence of CH(3)COONa under air atmosphere produced the S(N)Ar product [(C(9) H(6)NO)Ru{CHC(PPh(3))CHC(PPh(3))C}(C(9)H(6)NO)(PPh(3))]Cl(2) (3). Ruthenabenzene 3 could be stable in the solution of weak alkali or weak acid. However, reaction of 3 with NaOH afforded a 7:1 mixture of ruthenabenzenes [(C(9)H(6)NO)Ru{CHC(PPh(3))CHCHC}(C(9)H(6)NO)(PPh(3))]Cl (4) and [(C(9)H(6)NO)Ru{CHCHCHC(PPh(3))C}(C(9)H(6)NO)(PPh(3))]Cl (5), presumably involving a P-C bond cleavage of the metallacycle. Complex 3 was also reactive to HCl, which results in a transformation of 3 to ruthenabenzene [Ru{CHC(PPh(3))CHC(PPh(3))C}Cl(2)(C(9)H(6)NO)(PPh(3))]Cl (6) in high yield. Thermal stability tests showed that ruthenabenzenes 4, 5, and 6 have remarkable thermal stability both in solid state and in solution under air atmosphere. Ruthenabenzenes 4 and 5 were found to be fluorescent in common solvents and have spectral behaviors comparable to those organic multicyclic compounds containing large π-extended systems.     

Ring currents as probes of the aromaticity of inorganic monocycles : P5-, As5-, S2N2, S3N3-, S4N3+, S4N42+, S5N5+, S42+ and Se42+

Current-density maps were calculated by the ipsocentric CTOCD-DZ/6-311G** (CTOCD-DZ=continuous transformation of origin of current density-diamagnetic zero) approach for three sets of inorganic monocycles: S(4) (2+), Se(4) (2+), S(2)N(2), P(5) (-) and As(5) (-) with 6 pi electrons; S(3)N(3) (-), S(4)N(3) (+) and S(4)N(4) (2+) with 10 pi electrons; and S(5)N(5) (+) with 14 pi electrons. Ipsocentric orbital analysis was used to partition the currents into contributions from small groups of active electrons and to interpret the contributions in terms of symmetry- and energy-based selection rules. All nine systems were found to support diatropic pi currents, reinforced by sigma circulations in P(5) (-), As(5) (-), S(3)N(3) (-), S(4)N(3) (+), S(4)N(4) (2+) and S(5)N(5) (+), but opposed by them in S(4) (2+), Se(4) (2+) and S(2)N(2). The opposition of pi and sigma effects in the four-membered rings is compatible with height profiles of calculated NICS (nucleus-independent chemical shifts).     

Dititanium-containing 19-tungstodiarsenate(III) [Ti2(OH)2As2W19O67(H2O)]8-: synthesis, structure, electrochemistry, and oxidation catalysis

The dititanium-containing 19-tungstodiarsenate(III) [Ti(2)(OH)(2)As(2)W(19)O(67)(H(2)O)](8-) (1) has been synthesized and characterized by IR, TGA, elemental analysis, electrochemistry, and catalytic studies. Single-crystal X-ray analysis was carried out on Cs(8)[Ti(2)(OH)(2)As(2)W(19)O(67)(H(2)O)].2CsCl.12H(2)O (Cs-1), which crystallizes in the monoclinic system, space group P2(1)/m, with a=12.7764(19), b=19.425(3), c=18.149(3) A, beta=110.234(3) degrees, and Z=2. Polyanion 1 comprises two (B-alpha-As(III)W(9)O(33)) Keggin moieties linked through an octahedral {WO(5)(H(2)O)} fragment and two unprecedented square-pyramidal {TiO(4)(OH)} groups, leading to a sandwich-type structure with nominal C(2v) symmetry. Synthesis of 1 was accomplished by reaction of TiOSO(4) and K(14)[As(2)W(19)O(67)(H(2)O)] in a 2:1 molar ratio in aqueous, acidic medium (pH 2). Polyanion 1 could also be isolated as a tetra-n-butyl ammonium (TBA) salt, {(n-C(4)H(9))(4)N}(5)H(3)[Ti(2)(OH)(2)As(2)W(19)O(67)(H(2)O)] (TBA-1). TBA-1 was studied by cyclic voltammetry in acetonitrile (MeCN) solutions containing 0.1 M LiClO(4) and compared with the results obtained with Cs-1 in aqueous media. In MeCN, the Ti(IV) and W(VI) waves could not be separated distinctly. An important adsorption phenomenon on the glassy carbon working electrode was encountered both in cyclic voltammetry and in controlled potential electrolysis and was confirmed by Electrochemical Quartz Crystal Microbalance (EQCM) studies on a carbon film. TBA-1, dissolved in MeCN, reacts with H(2)O(2) to give peroxo complexes stable enough for characterization by UV-visible spectroscopy, cyclic voltammetry, and EQCM. TBA-1 shows high catalytic activity (TOF=11.3 h(-1)) in cyclohexene oxidation with aqueous H(2)O(2) producing products typical of a heterolytic oxidation mechanism. The stability of TBA-1 under turnover conditions was confirmed by using IR, UV-visible spectroscopy as well as cyclic voltammetry.     

Convenient syntheses of fluorous aryl iodides and hypervalent iodine compounds: ArI(L)n reagents that are recoverable by simple liquid/liquid biphase workups,and applications in oxidations of hydroquinones

Iodinations of the ortho, meta, and para fluorous arenes (R(f8)CH(2)CH(2)CH(2))(2)C(6)H(4) (R(f8)=(CF(2))(7)CF(3)) with I(2)/H(5)IO(6) in AcOH/H(2)SO(4)/H(2)O give 3,4-(R(f8)CH(2)CH(2)CH(2))(2)C(6)H(3)I (5) and the analogous 2,4- (6) and 2,5- (7) isomers, respectively. Spectroscopic yields are >90 %, but 5 and 7 must be separated by chromatography from by-products (yields isolated: 70 %, 97 %, 61 %). Reaction of 1,3,5-(R(f8)CH(2)CH(2)CH(2))(3)C(6)H(3) with PhI(OAc)(2)/I(2) gives 2,4,6-(R(f8)CH(2)CH(2)CH(2))(3)C(6)H(2)I (8) on multigram scales in 97 % yield. The CF(3)C(6)F(11)/toluene partition coefficients of 5-8 (24 degrees C: 69.5:30.5 (5), 74.7:25.3 (6), 73.9:26.1 (7), 98.0:2.0 (8)) are lower than those of the precursors, but CF(3)C(6)F(11)/MeOH gives higher values (97.0:3.0 (5), 98.6:1.4 (6), 98.0:2.0 (7), >99.3:<0.3 (8)). Reactions of 5-8 with excess NaBO(3) in AcOH yield the corresponding ArI(OAc)(2) species 9-12 (9, 85 % as a 90:10 9/5 mixture; 10, 97 %; 11, 95 %; 12, 93 % as a 95:5 12/8 mixture). These rapidly oxidize 1,4-hydroquinones in MeOH. Subsequent additions of CF(3)C(6)F(11) give liquid biphase systems. Solvent removal from the CF(3)C(6)F(11) phases gives 5-8 in >99-98 % yields, and solvent removal from the MeOH phases gives the quinone products, normally in >99-95 % yields. The recovered compounds 5-8 are easily reoxidized to 9-12 and used again.