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Ionic Liquids 离子液体

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张娟 / 邓友全
656.89 KB

With various RTILs as templates, amorphous mesoporous silica gel materials were synthesized according to a proper sol–gel method. The materials display pore diameter of 3–12 nm, pore volume of 0.4–1.3 cm3/g and BET surface area of 300–800 m2/g. The effect of variations of the anions and cations of ILs, the alkylchain length on imidazolium cation and IL concentration in the reaction system on the pore structure and thermal stability of the silicagel materials was preliminarily studied. It is suggested that, the pore size of silica gel can be tuned by variations of ILs and IL content. The different kind of the anions of ILs could largely impact the properties of the obtained silica gel materials. The mesoporous silica gels with 1-alkyl-3-ethylimidazolium tetrafluoroborate as templates possessed larger pore sizes of 5–12 nm and higher thermal stability than the materials obtained with other ILs as templates.

Keywords: Confined; Ionic liquid; Mesoporous; Silica gel; Sol–gel

★★★☆☆ Zhang J,Ma YB,Shi F,et al. Room Temperature Ionic Liquids As Templates In The Synthesis Of Mesoporous Silica Via A Sol–gel Method[J]. Microporous And Mesoporous Materials,2009,119:97-103.

张世国 / 邓友全
233.14 KB

Photochromism of spiropyran and thermal reversion of MC in a series of imidazolium-based ionic liquids (ILs) were investigated via fluorescence and UV-vis absorption spectra. The fluorescence emission maxima (λem) of the colored merocyanine (MC) form is polarity dependent in all ILs and fluorescence intensity enhancement was first observed in ILs with respect to that observed in organic solvents (e.g., in [HOMIm][PF6], nearly 32-fold enhancement than ethanol). Moreover, the thermal decay of MC in all ILs is uniformly first order, and in comparison with polar solvents possessing comparable polarity (such as ethanol and acetonitrile), a significant retardation of the decay rate and increase of half-lifetime of MC form was observed, in particular at elevated temperature (e.g., at 313 K, MC decay with k of 5.19 × 10-4 and 34.7 × 10-4 s-1 in [BMMIm][BF4] and ethanol, respectively). Abnormal thermodynamics of the thermal decay of MC in ILs were observed, activation energies in less polar ILs (88-97 kJ mol-1) have a larger value than in polar ILs (70-82 kJ mol-1), opposite that in organic solvents (70-80 kJ mol-1 in nonpolar solvents and around 100 kJ mol-1 in polar solvents), and all ILs exclusively exhibit minus activation entropies (-85.4 to -24.5 J K-1 mol-1), similar to that of nonpolar solvents. Desolvation due to the conformational change during the thermal reversion between MC and the transition state may be the key to interpret this experimental result.

★★★☆☆ Zhang SG,Zhang QH,Ye BX,et al. Photochromism Of Spiropyran In Ionic Liquids: Enhanced Fluorescence And Delayed Thermal Reversion[J]. J. Phys. Chem. B,2009,113(17):6012-6019.

郭晓光 / 邓友全
274.37 KB

A series of catalysts (e.g. FeCl3, Zn(OAc)2, Pb(NO3)2, etc.) were tested for the trans-esterification reaction of 1,6-hexamethylenediamine (HDA) with methyl carbamate (MC), ethyl carbamate (EC), and butyl car-bamate (BC) to afford dialkyl hexamethylene-1,6-dicarbamate (AHDC). By applying the optimized condi-tion, 100% conversion of HDA and 93% yield to diethyl hexamethylene-1,6-dicarbamate (EHDC) could be obtained using FeCl3 as catalyst. The desired products could be precipitated by adding water into the resulting mixture, and the activity of recovered catalyst could be maintained.

Keywords: Non-phosgene; Carbamate; Carbonylation; 1,6-Hexamethylenediamine; Isocyanate

★★★☆☆ Guo XG,Shang JP,Ma XY,et al. Synthesis Of Dialkyl Hexamethylene-1,6-dicarbamate From 1,6-hexamethylenediamine And Alkyl Carbamate Over Fecl3 As Catalyst[J]. Catalysis Communications,2009,10:1248-1251.

李作鹏 / 邓友全
1.94 MB

The in situ electropolymerized-polyaniline (PANI) film (thickness: 5–20 l m) on FTO (fluorine tin oxide) glass doped by various counterions SO2-4, ClO-4 ,BF-4,Cl-, p-toluenesulfonate (TsO-), etc. was prepared with electropolymerized charge capacity of 50–600 mC cm-2. Different doping counterions have great impact on the morphology, electrochemical activity of electropolymerized-PANI film. The electropoly-merized-PANI doped by SO24 anion (PANI-SO4) film with much porous morphology and pore size diam-eter of several micrometers possesses higher reduction current for reduction of I-3 and a low charge-transfer resistance of 1.3 Ω cm2 in comparison with Pt as counter electrode (CE). Dye-sensitized solar cell with PANI-SO4 as CE was assembled, and the device under full sunlight illumination (100 mW cm-2,AM1.5 G) shows 5.6% photovoltaic conversion efficiency, which is comparable to 6.0% of that with Pt CE under the same experimental condition.

Keywords: Dye-sensitized solar cell; Polyaniline; Electropolymerization; Counter electrode

★★★★☆ Li ZP,Ye BX,Hu XD,et al. Facile Electropolymerized-pani As Counter Electrode For Low Cost Dye-sensitized Solar Cell[J]. Electrochemistry Communications,2009,11:1768-1771.

328.16 KB

★★★★★ Shi F,Man Kin Tes,Cui XJ,et al. Copper-catalyzed Alkylation Of Sulfonamides With Alcohols[J]. Angew. Chem. Int. Ed.,2009,48:5912-5915.

283.07 KB

The N-alkylation of sulfonamides with alcohols is efficiently performed in the presence of easily available copper catalysts via hydrogen borrowing methodology. Applying a copper acetate/potassium carbonate system the reaction of sulfon-ACHTUNGTRENUNGamides and alcohols gave the corresponding secondary amines in excellent yield. In situ HR-MS analysis indicated that bissulfonylated amines are formed under air atmosphere, which act as self-stabilizing ligands for the catalytic system. UV-visible measurements suggest the interaction between the copper centre and the bissulfonylated amine. Reactions of benzyl alcohol-d7 with p-toluenesulfonamide, Nbenzyl-p-toluenesulfonamide or N-benzylidenetolu-ACHTUNGTRENUNGenesulfonamide revealed that the reaction proceeds via a transfer hydrogenation mechanism and the whole process is micro-reversible. Competitive reactions of benzyl alcohol and benzyl alcohol-d7 with ptoluenesulfonamide revealed a kinetic isotope effect (kH/kD) of 3.287 (0.192) for the dehydrogenation of benzyl alcohol and 0.611 (0.033) for the hydrogenation of the N-benzylidene-p-toluACHTUNGTRENUNGenesulfonamide intermediate, which suggests that dehydrogenation of the alcohol is the rate-determining step.

Keywords: alcohols; alkylation; CN bond formation; copper catalysts; sulfonamides

★★★☆☆ Cui XJ,Shi F,Man Kin Tes,et al. Copper-catalyzed N-alkylation Of Sulfonamides With Benzylic Alcohols: Catalysis And Mechanistic Studies[J]. Adv. Synth. Catal.,2009,351:2949-2958.

乔波涛 / 邓友全
469.31 KB

Ferric hydroxide supported Pd catalyst prepared by a simple co-precipitation method without calcinations at elevated temperatures and only reduced at 50◦C possessed unexpectedly higher activity for CO oxidations even compared with that of supported Au catalysts. XRD and TEM results showed that the support was mixture of Fe(OH)x and Fe3 O4 and Pd was highly dispersed on it. XPS results showed that Pd existed as mixture of oxidation and metal state. The large amount of OH group on the supports may play an important role in O adsorption and activation.

Keywords: Gold; Palladium; CO oxidations; Ferric hydroxide; Low temperature

★★★☆☆ Qiao BT,Liu LQ,Zhang J,et al. Preparation Of Highly Effective Ferric Hydroxide Supported Noble Metal Catalysts For Co Oxidations: From Gold To Palladium[J]. Journal Of Catalysis,2009,261:241-244.

张庆华 / 邓友全
462.03 KB

A new series of ionic liquids composed of three cyclic sulfonium cations and four anions has been synthesized and characterized. Their physicochemical properties, including their spectroscopic characteristics, ion cluster behavior, surface properties, phase transitions, thermal stability, density, viscosity, refractive index, tribological properties, ion conductivity, and electrochemical window have been comprehensively studied. Eight of these salts are liquids at room temperature, at which some salts based on [NO3] and [NTf2] ions exhibit organic plastic crystal behaviors, and all the saccharinbased salts display relatively high refractive indices (1.442–1.594). In addition, some ionic liquids with the [NTf2] ion exhibit peculiar spectroscopic characteristics in FTIR and UV/Vis regions, whilst those salts based on the [DCA] ion show lower viscosities (34.2–62.6 mPas at 20℃) and much higher conductivities (7.6–17.6 mScm-1 at 20℃) than most traditional 1,3-di-ACHTUNGTRENUNGalkylimidazolium salts.

Keywords: electrochemistry · ionic liquids · performance · physicochemical properties · sulfonium ions

★★★★☆ Zhang QH,Liu SM,Li ZP,et al. Novel Cyclic Sulfonium-based Ionic Liquids: Synthesis, Characterization, And Physicochemical Properties[J]. Chem. Eur. J.,2009,15:765-778.

刘乐全 / 邓友全
523.44 KB

Chemoselective hydrogenation of aromatic nitro compounds were first efficiently achieved over Au/Fe(OH)x at 100–120 1C for 1.5–6 h (depending on different substrates) in the presence of CO and H2O.

★★★★☆ Liu LQ,Qiao BT,Chen ZJ,et al. Novel Chemoselective Hydrogenation Of Aromatic Nitro Compounds Over Ferric Hydroxide Supported Nanocluster Gold In The Presence Of Co And H2o[J]. Chemical Communications,2009:653-655.