Dawson结构磷钼钒酸铯催化H_2O_2氧化苯合成苯酚

采用乙醚反萃取方法合成了Dawson结构磷钼钒酸H8P2Mo16V2O62,进而与碳酸铯反应得到Dawson结构磷钼钒酸铯催化剂CsnH8-nP2Mo16V2O62(n=1-5),利用X射线粉末衍射(XRD)、红外(FTIR)以及SEM等对催化剂进行分析,并以H2O2为氧化剂,评价其在苯液相氧化直接羟基化合成苯酚反应中的催化性能,系统的研究了反应时间、催化剂用量、H2O2用量、反应溶剂等反应条件对催化反应的影响。结果表明,合成Cs3H5P2Mo16V2O62在催化反应中表现出优良的催化活性,优化条件下,苯酚收率达到31.0%;催化剂回收方便,可多次重复使用,在反应过程中,催化剂的Dawson结构没有明显变化。     

Dowson型钼钒磷杂多酸催化H2O2氧化蒽制备蒽醌

合成了5种Dowson型杂多酸催化剂(Pn),并用于催化H2O2氧化蒽制备蒽醌的反应.结果表明Hs[P2Mo14V4O62H2](P5)的催化活性最好.最佳的氧化反应条件为:蒽5.6 mmol,n(蒽):n(H2O2)=1:11,P530 mg,溶剂正丁醇,于70 ℃反应1 h,产率达93.2%.     

(NH4)11Gd[Gd4Mo29O100(H2O)16]·33H2O杂多化合物在苯酚羟化反应中的催化活性

对苯二酚;过氧化氢;(NH4)11Gd[Gd4Mo29O100(H2O)16]·33H2O杂多化合物在苯酚羟化反应中的催化活性     

Keggin型磷钼钒季铵盐催化氧化苯制苯酚反应研究

采用分步反应、分步酸化法制备了磷钼钒缺位型杂多酸,用（C4H9）4N^＋（以下简写为Bu4N^＋）阳离子取代杂多酸中H^＋作为反荷离子合成了杂多季铵盐（用于苯氧化制苯酚反应）．FT-IR分析反应前后催化剂结构的变化．以苯为原料,乙酸为溶剂,30％H2O2作氧化剂,系统考察了催化剂类型、催化剂用量、氧化剂用量、反应时间及温度对反应的影响．实验结果表明,56．4mmol苯在（Bu4N）5PMo10V2O40用量0．25mmol,30％H2O2用量10mL,溶剂乙酸10mL,70℃条件下回流反应6h,苯酚收率可达到27．9％．     

Synthesis, Characterization and Inhibition Effects of Vanadium Substituted Dawson-type Heteropoly Acids(Mo, P)

Four new vanadium substituted Dawson-type heteropoly acids H7[P2Mo17VO62]·39H2O(1), H8[P2Mo16V2O62]·41H2O(2), H9[P2Mo15V3O62]·51H2O(3) and H8[P2Mo14V4O62H2]·45H2O(4) were prepared respec-tively. Their structures were determined by IR and ICP. The inhibition effects of vanadium substituted Dawson-type heteropoly acids(Mo, P) on free radical polymerization of methyl methacrylate(MMA) were investigated by dilatometry. The results show that the rate of the polymerization of MMA decreases and the inhibition effe...     

钨磷杂多酸盐的合成、表征及催化活性

合成了4个钨磷杂多酸盐——K10H2[P2W15Ti3O62]·2H2O,K12[P2W15(TiO2)3O59]·8H2O,K12[P2W15Zr3O62]·6H2O和K12[P2W15(ZrO2)3O59]·5H2O,用183WNMR,UV,IR,ICP和极谱-循环伏安等测试方法对其性质、结构进行了研究。结果表明它们都是具有Dawson结构的杂多配合物,对顺丁烯二酸的H2O2环氧化反应具有显著的催化活性。     

钨过氧酸盐离子液体催化过氧化氢氧化苯甲醇制苯甲酸

用甲基三辛基氯化铵和钨酸钠一步法合成甲基三辛基季铵钨酸盐离子液体[(CH3)N(n-C8H17)3]2W2O11,以该离子液体为催化剂,在无反应溶剂条件下催化过氧化氢氧化苯甲醇生成苯甲酸。 考察了反应温度、催化剂用量以及氧化剂过氧化氢用量对苯甲酸产率的影响。 确定优化条件：反应温度70 ℃,苯甲醇用量5 mmol,催化剂用量是底物的0.4%(摩尔分数),30%过氧化氢用量2 mL,苯甲醇的转化率可达99%,苯甲酸选择性为98%。 该方法具有反应条件温和、产率高和选择性好的优点。     

(NH4)15[La(PMo9V2O39)2].6H2O 杂多配合物对苯酚羟化的催化作用

合成了(NH4)15[La(PMo9V2O39)2].6H2O杂多配合物, 并考察其对苯酚过氧化氢羟化反应的催化活性. 探讨了温度、催化剂用量、反应时间、 n(PhOH)/n(H2O2)摩尔比以及反应介质的pH值对反应的影响. 实验结果表明, 以甲醇为溶剂、 n(PhOH)/n(H2O2)=1∶2、反应体系的pH值为5左右、反应温度343 K、反应时间约4 h的条件下, 苯酚转化率可达44.30%, 对苯二酚产率达43.35%. 并采用ICP、 IR、 UV和XRD等技术, 对(NH4)15[La(PMo9V2O39)2].6H2O进行表征, 初步证实了(NH4)15[La(PMo9V2O39)2].6H2O具有Keggin结构.     

功能化离子液体[bmim]OTs催化乙酰化反应

以离子液体1-丁基-3-甲基咪唑四氟硼酸盐([bmim]BF4)为溶剂,对甲基苯磺酸根(OTs-)为阴离子的功能化离子液体[bmim]OTs为催化剂进行苯甲醇的乙酰化反应.结果表明,该体系循环使用10次后仍能保持良好的催化活性和稳定性,并对各种(伯、仲、叔)醇类、酚类和胺类化合物的乙酰化反应表现出良好的普适性.核磁共振波谱(13C NMR)分析结果表明,具有亲核性的[bmim]OTs和酰化试剂乙酸酐(Ac2O)形成的活性中间体AcOTs,是催化反应的活性物种.     

具有Dawson结构的钼钒磷杂多酸的制备和性质研究

本文报道用改良的分步处理合成方法, 直接制备了五种未见报道的2:18系列钼钒磷杂多酸, 详细考察了它们的生成条件. 经元素分析、电位滴定和差热热重分析确定阴离子的组成分别为[P2Mo17VO62]^7^-,[P2Mo16V2O62]^8^-,[P2Mo15V3O62]^9^-, [P2Mo14V4O62H2]^8^-, [P2Mo13V5O62H2]^9^-. 对五种杂多酸的热化学性质和碱度进行了讨论. 根据紫外、红外及X射线衍射结果讨论了它们的结构, 表明都属于具有Dawson结构的杂多化合物.     

Surface-functionalized ionic liquid crystal-supported ionic liquid phase materials: ionic liquid crystals in mesopores

The influence of confinement on the ionic liquid crystal (ILC) [C(18)C(1)Im][OTf] is studied using differential scanning calorimetry (DSC), polarized optical microscopy (POM), and diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS). The ILC studied is supported on Si-based powders and glasses with pore sizes ranging from 11 to 50 nm. The temperature of the solid-to-liquid-crystalline phase transition seems mostly unaffected by the confinement, whereas the temperature of the liquid-crystalline-to-liquid phase transition is depressed for smaller pore sizes. A contact layer with a thickness in the order of 2 nm is identified. The contact layer exhibits a phase transition at a temperature 30 K lower than the solid-to-liquid-crystalline phase transition observed for the neat ILC. For applications within the "supported ionic liquid phase (SILP)" concept, the experiments show that in pores of diameter 50 nm a pore filling of α>0.4 is sufficient to reproduce the phase transitions of the neat ILC.     

Recognition of ionic guests by ionic beta-cyclodextrin derivatives

Inclusion compounds of cationic, anionic, and neutral p-substituted derivatives of tert-butylbenzene complexed in beta-cyclodextrin and its ionic 6-mono and 6-hepta derivatives were systematically investigated by isothermal titration calorimetry (ITC). All inclusion compounds showed 1:1 stoichiometry with binding constants ranging from 10 to 3 x 10(6) M(-1). The binding free energies could be subdivided into apolar and electrostatic contributions. The electrostatic interactions could be quantitatively described by Coulomb's law by taking into account the degree of protonation of hosts and guests, the orientations of the guests within the hosts, and ion shielding as described by the Debye-Hückel-Onsager theory. The orientations of the guests within the cyclodextrin cavities were determined by ROESY NMR spectroscopy.     

Synthesis and ionic conductivity of polymer ionic liquids

Four vinyl monomers containing a covalently bonded cation ethylimidazolium and various anions—Br^?, (CF₃SO₂)₂N^?, (CN)₂N^?, and CF₃SO ₃ ^? —have been synthesized. High-molecular-mass polymers (M _w up to 1.84 × 10⁶) having the structure of ionic liquids have been prepared via the free-radical polymerization of 1-vinyl-3-ethylimidazolium in bulk and molecular and ionic solvents. The thermal stability and heat resistance of the resulting polymer salts have been estimated. It has been demonstrated that the thermal characteristics of these salts significantly depend on the nature of anions. The glass-transition temperatures of the polymers range from 19 to 235°C. The ionic conductivity of the polymer salts and their compositions with individual ionic liquids has been studied in the frequency range 50–10⁶ Hz. The highest conductivity (1.5 × 10^?5 S/cm) is exhibited by the polymer containing the (CN)₂N^? anion.     

Surface tension of ionic liquids and ionic liquid solutions

Some of the most active scientific research fronts of the past decade are centered on ionic liquids. These fluids present characteristic surface behavior and distinctive trends of their surface tension versus temperature. One way to explore and understand their unique nature is to study their surface properties. This critical review analyses most of the surface tension data reported between 2001 and 2010 (187 references).     

Water-soluble ionic benzoporphyrins

Novel ionic water-soluble tetrabenzoporphyrins have been successfully synthesized via a cascade reaction based on the Heck reaction. The UV-Vis spectra of these porphyrins displayed red-shifted and broadened Soret bands, and significantly enhanced Q bands. These porphyrins are highly water soluble.     

Polyampholyte-modified ionic microemulsions

This paper is focused on the influence of added polyampholyte, namely poly(N,N′-diallyl-N,N′-dimethyl-alt-maleamic carboxylate) on the inverse micellar phase range of the pseudo-ternary system consisting of toluene–pentanol (1:1)/SDS/water in dependence on the pH value and the temperature. Investigations on phase behavior have revealed that a greater extension in direction to the water-rich corner can be found at pH 4 compared to pH 9. In order to understand changes in the microstructure, polymer–surfactant interactions in dependence on pH have been examined by means of diffusion-ordered spectroscopy, differential scanning calorimetry, as well as conductivity measurements. The results have proven that the present microemulsion consists of water-in-oil droplets, with the polyampholyte located more in the inner core of the water droplets at pH 9 rather than at the interphase of the surfactant film at pH 4.     

Guanidinium-based ionic liquids

Cyclic (subset=N+<, subset = imidazolidine 3 and 4, hexahydro-pyrimidine 7 and 8, tetrahydro-1,3,5-oxadiazine 12, and triazoline 15 and 16) and acyclic [(R2N)2C=N+<, 19] guanidinium-based salts were synthesized via the quaternization of guanidine derivatives with nitric or perchloric acid or with iodomethane followed by metathesis reaction with silver nitrate, silver perchlorate, or ammonium dinitroamide. The structure of 15d was confirmed by single-crystal X-ray analysis. Most of the salts exhibited low melting points and good thermal stabilities. Their densities range between 1.2 and 1.5 g/cm3. Standard molar enthalpies of formation were calculated from experimentally determined constant-volume combustion energies obtained using an oxygen bomb calorimeter.     

Aggregation behavior of long-chain ionic liquids in an ionic liquid

The aggregation behavior of long-chain ionic liquids 1-alkyl-3-methylimidazolium bromide (C(n)mimBr) in another ionic liquid, 1-butyl-3-methylimidazolium tetrafluoroborate (bmimBF(4)), was studied for the first time. Surface tension measurements revealed that aggregates are formed by C(n)mimBr, and freeze fracture transmission electron microscopy (FF-TEM) observations suggested the aggregates are spheres with a size much larger than traditional micelles. The sizes of the aggregates were further confirmed by dynamic light scattering (DLS) measurements.     

Methimazole-based ionic liquids

The alkylation reaction of 2-mercapto-1-methylimidazole 1a with iodoethane and chlorobutane produced S-alkylmethimazole halides 2a and 2b which were subjected to anion metathesis with two different metal salts (MA) to afford methimazole-based room-temperature ionic liquids 3a, 3b, and 3c in 82%, 85%, and 87% yields, respectively. S-Alkylation giving 2a and 2b suggests that methimazole reacts through the thione tautomer.