通过一步法合成了基于1,3-二烷基咪唑阳离子和甲烷磺酸或对甲苯磺酸阴离子的无卤素离子液体, 并对它们的物理化学性质如聚集行为、表面性质、热性质、密度、黏度、折光率和电化学性质等进行了详细研究. 结果表明在甲烷磺酸阴离子基离子液体中观察到离子液体中普遍存在的离子簇行为; 同等条件下[BEim]MS的荧光光谱强度较[BEim] TS弱; [C12Mim ]M S展现出液晶行为; [TS] - 基离子液体有着较高的折光率, 大于1.51

Keywords: Sulfonate; Ionic liquids; Halogen-free; Synthesis; Physicochemical property

★★☆☆☆ Li XL,Li ZP,Liu SM,et al. Physicochemical Properties Of Halogen-free 1,3-dialkylimidazolium Ionic Liquids Based On The Sulfonate Anions[J]. 分子催化,2010,24(6):483-491.

★★★☆☆ Zhang SG,Hu XD,Qu C,et al. Enhanced And Reversible Contact Angle Modulation Of Ionic Liquids In Oil And Under Ac Electric Field[J]. Chemphyschem,2010,11:2327-2331.

The FeCl2/K2CO3 catalyst system was developed successfully for the N-alkylation of sulfonamides with benzylic alcohols via borrowing hydrogen method. XPS analysis gested a possible catalyst cycle between Fe(II) and Fe(0). Under the optimized condition, the scope of the protocol was demonstrated in 21 different alkylation reactions. High yields, in general >90%, are achieved in most cases.

Keywords: Sulfonamide; Alkylation; Alcohol; Iron

★★★★☆ Cui XJ,Shi F,Zhang Y,et al. Fe(ii)-catalyzed N-alkylation Of Sulfonamides With Benzylic Alcohols[J]. Tetrahedron Letters,2010,51:2048-2051.

The polarity of a series of ionic liquids (ILs) based on hydroxyethyl-imidazolium moiety with various anions ([PF6], [NTf2], [ClO4], [DCA], [NO3], [AC], and [Cl]) and their corresponding nonhydroxyl ILs was investigated by solvatochromic dyes and fluorescence probe molecules. Most of the nonhydroxyl ILs exhibit anionindependent polarity with similar ET(30) in the narrow range of 50.7-52.6 kcal/mol, except [EMIm][AC] (49.7 kcal/mol). However, the polarity of the hydroxyl ILs covers a rather wide range (ET(30) ) 51.2-61.7 kcal/mol) and is strongly anion-dependent. According to their ET(30) or ET(33) values, the hydroxyl ILs can be further classified into the following three groups: (Ι) acetate-based hydroxyl ILs [HOEMIm][AC] exhibit polarity scale (ET(30) ) 51.2 kcal/mol) similar to short chain alcohol and fall in the range of the nonhydroxyl ILs; (II) Hydroxyl ILs containing anions [NO3], [DCA], and [Cl] exhibit comparable polarity (ET(30) ) 55.5-56.9 kcal/mol), moderately higher than those of their nonhydroxyl ILs; (III) Hydroxyl ILs containing anions [PF6], [NTf2], and [ClO4] possess unusual “hyperpolarity” (ET(30) ) 60.3-61.7 kcal/mol) close to protic ILs and water. Kamlet-Taft parameters and density functional theory calculations indicated that the greatly expanded range of polarity of hydroxyl ILs is correlated to an intramolecular synergistic solvent effect of the ionic hydrogen-bonded HBD/HBA complexes generated by intrasolvent HBD/HBA association between the anions and the hydroxyl group on cations, wherein hydroxyl group exhibits a significant differentiating effect on the strength of H-bonding and thus the polarity. Spiropyran-merocyanine equilibrium acted as a model polarity-sensitive reaction indeed shows obviously polarity-dependent solvatochromism, photochromism, and thermal reversion in hydroxyl ILs.

★★★☆☆ Zhang SG,Qi XJ,Ma XY,et al. Hydroxyl Ionic Liquids: The Differentiating Effect Of Hydroxyl On Polarity Due To Ionic Hydrogen Bonds Between Hydroxyl And Anions[J]. J. Phys. Chem. B,2010,114:3912-3920.

A series of FeOx- and Al2O3-supported Pt, Pd catalysts (0.23–2.1%) were prepared in this study. Pt/FeOx exhibited high CO oxidation activity with turnover frequency of 151 10 3 s 1 (1% CO balanced with air, atmospheric pressure, 27 C). A systematical study of FeOx- and Al2O3-supported Pt, Pd catalysts by means of X-ray photoelectron spectroscopy, X-ray diffraction, high-resolution transmission electron microscopy, temperature-programmed reduction, H2–O2 titration, and time-resolved CO titration is reported. From 7% to 39% of Fe3+ was reduced to Fe2+ over Fe(OH)x-supported Pd and Pt catalysts, accompanied by Pd, Pt hydrogenation and hydroxyl loss, and a large amount of oxygen vacancies were proposed to be produced. Results of H2–O2 titration and time-resolved CO titration showed that a large amount of oxygen adsorbed onto FeOx support in the presence of Pt, Pd. This made CO oxidations over Pt/FeOx, Pd/FeOx proceed over two adjacent but different active sites (Pt, Pd for CO and FeOx for oxygen) with low apparent activation energies (30–34 kJ/mol), which accounted for their high activity in low-temperature CO oxidation.

Keywords: CO oxidation;  Pt catalyst;  Pd catalyst;  Kinetic measurements;  Strong metal–support interaction (SMSI);  effect;  Oxygen vacancy;  H2–O2 titration;  Time-resolved CO titration

★★★☆☆ Liu LQ,Zhou F,Wang LG,et al. Low-temperature Co Oxidation Over Supported Pt, Pd Catalysts: Particular Role Of Feox Support For Oxygen Supply During Reactions[J]. Journal Of Catalysis,2010,274:1-10.

A series of nanocomposites of ionic liquids (ILs) were prepared via a modified sol–gel method. The ILs were physically confined in mesoporous silica gels with 5–40% content. ILs from imidazolium, thiophenium and ammonium with different anions were prepared and used. Characterization using the Brunauer–Emmett–Teller (BET) method, Fourier transform infrared (FT-IR) spectroscopy, temperature-programmed desorption (TPD), differential scanning calorimetry (DSC), inverse gas chromatography (IGC), temperature-controlled Raman and fluorescence emission spectroscopies was conducted to explore any confinement effects. BET results showed that, depending on the ILs and their contents, the average pore diameter of the pure silica gel was 3–12 nm after the confined ILs were removed completely. It was suggested that ILs aggregated on the nanoscale in the mesoporous silica gel. In comparison with bulk ILs and ILs coated onto silica gels (IL/sg), IL nanocomposites (IL–sg) displayed remarkably low specific heat capacities (Cp was in the range 0.3–1.2 Jg-1K-1), disordered vibrational conformations (without phase transitions in the range 100–200 1C), greater interactions with hydrocarbon solutes (adsorption capacities of 0.3–0.4 g per 100 g for confined ILs with CO2 gas), and greatly enhanced fluorescence emission (up to 200 times stronger than bulk ILs). Furthermore, Based on the specific solubility of different compounds, the nanocomposites could also be applied to the separation of CO2 from CO2/N2 mixtures and thiophene from thiophene/octane mixtures.

★★★★☆ Zhang J,Zhang QH,Li XL,et al. Nanocomposites Of Ionic Liquids Confined In Mesoporous Silica Gels: Preparation, Characterization And Performance[J]. Physical Chemistry Chemical Physics,2010,12:1971-1981.

The integration of a free metal complex, Pd(phen)2+, and a room temperature ionic liquid (IL) solvent molecule, 1-decyl-3-methyl imidazolium bromide, into a complete catalytically active site and confined in a NaY zeolite super-cage with an appropriate spatial arrangement was investigated. This integration was achieved through a molecular self-assembly method. A preliminary test of this catalyst system for the carbonylation of aniline to methyl phenyl carbamate indicated that far higher catalytic activity could be achieved (TOF increased from 3 000 to 23 000 h–1) with far lower amounts of the IL solvent and the Pd complex in comparison with a simple mixture of Pd(phen)Cl2/IL/NaY as the catalyst. This new system can also be applied to other areas of catalysis.

Key words: active site; ionic liquid; metal complex; carbonylation; aniline; phenyl methyl carbamate; turnover frequency

★★★☆☆ Ma YB,He YD,Zhang QH,et al. Self-assembly Of Ionic Liquids And Metal Complexes In Super-cages Of Nay: Integration Of Free Catalysts And Solvent Molecules Into Confined Catalytic Sites[J]. Chinese Journal Of Catalysis,2010,31(8):933-937.

★★★★☆ Cui XJ,Zhang SG,Shi F,et al. The Influence Of The Acidity Of Ionic Liquids On Catalysis[J]. Chemsuschem,2010,3:1043-1047.

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.

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.