Ferric hydroxide supported Au catalysts prepared with co-precipitation method at room temperature without any heat treatment hereafter exhibited high catalytic activity and selectivity for CO oxidation in air and CO selective oxidation in the presence of H2. With calcination temperature rising, both activity and selectivity decreased. X-ray Photoelectron Spectra (XPS) indicated that Au existed as Au0 and Au+ in the catalyst without heat treatment and even after being calcined at 200 ℃, while after being calcined at 400 ℃, Au existed as Au0 completely. X-ray Diffraction (XRD) and High Resolution Transmission Electron Microscopic (HRTEM) investigations indicated that both the supports and Au species were highly dispersed as nano or sub-nano particles even after being calcined at 200 ℃, but after being calcined at 400 ℃ the supports transformed to crystal Fe2O3 with typical diameter of 30 nm and Au species aggregated to nano-particles with typical diameter of 2–4 nm. HRTEM investigations also suggested that the supports calcined at 200 ℃ were composed of amorphous ferric hydroxide and crystal ferric oxide. Results of computer simulation (CS) showed that O2 was adsorbed on Au crystal cell and then were activated, which should be the key factor for the subsequent reaction. It also suggested that O2 species were more easily adsorbed on Au+ than on Au0, indicating that higher positive charge of the Au species possessed the higher activity for CO oxidation.

Keywords: Gold catalyst; CO selective oxidation; Preparation; Uncalcined; Low-temperature

★★★☆☆ Qiao BT,Zhang J,Liu LQ,et al. Low-temperature Prepared Highly Effective Ferric Hydroxide Supported Gold Catalysts For Carbon Monoxide Selective Oxidation In The Presence Of Hydrogen[J]. Applied Catalysis A: General,2008,340:220-228.

1-Ethyl-3-methylimidazolium dicyanamide EMImN(CN)2 and S-ethyltetrahydrothiophene dicyanamide EThN(CN)2 physically confined into mesoporous silica gel with pore sizes of 6–8 nm (IL-sg) were synthesized according to a proper sol–gel process. Greatly enhanced fluorescence emissions of dicyanamide based ILs after being confined were exhibited.

★★★☆☆ Zhang J,Zhang QH,Shi F,et al. Greatly Enhanced Fluorescence Of Dicyanamide Anion Based Ionic Liquids Confined Into Mesoporous Silica Gel[J]. Chemical Physics Letters,2008,461:229-234.

The non-phosgene carbonylation of 1,6-hexamethylenediamine (HDA) with alkyl carbamates using Y(NO3)3·6H2O as a catalyst and the influence of reaction variables on the yields of dialkyl hexamethylenedicarbamate (HDC) were studied. At 453K and in the presence of 5 wt.% Y(NO3)3·6H2O, nearly 100% HDA conversion and 85% dibutyl hexamethylenedicarbamate (BHDC) isolated yield could be achieved when butyl carbamate (BC) was employed as a carbonyl source. During reaction, an induction periodwas observed, but it almost disappeared by pretreating the catalyst with n-butanol. The FT-IR, X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) characterizations of the catalyst showed that some transformation occurred when the catalyst was pretreated with n-butanol or employed during reaction, i.e., part decomposition of Y(NO3)3 to Y2O3, conversion from crystal to amorphous state, changes occurring in chemical state of the active species, as well as some subtle interactions between the catalyst and n-butanol. All these observed changes might be the reason resulting in activation of the catalyst.

Keywords: Green chemistry; Alkyl carbamate; Dialkyl hexamethylenedicarbamate; 1,6-Hexamethylenediamine; Non-phosgene

★★★☆☆ Zhang HZ,Guo XG,Zhang QH,et al. Synthesis Of Dialkyl Hexamethylenedicarbamate From 1,6-hexamethylenediamine And Alkyl Carbamate Over Y(no3)3·6h2o Catalyst[J]. Journal Of Molecular Catalysis A: Chemical,2008,296:36-41.

Microwave enhanced syntheses of 9-boronobenzyladenine derivatives by the reaction of adenine with the corresponding bromomethylphenylboric acid were reported. Microwave irradiation reduced the overnight reaction time of conventional thermal methods to 10 min, provided the desired products and increased the yields up to three times. Preliminary in vitro pharmacological tests were also described.

Keywords: 9-boronobenzyladenines, anti-inflammatory, antitumor, microwave-asisted synthesis

★★★☆☆ Yu XJ,Liu W,Hu WD,et al. Microwave Assisted Synthesis And Biological Activities Of 9-boronobenzyladenine Derivatives[J]. Journal Of Chemical Research,2007:347-349.

A series of ionic liquids (ILs) based on nitrile-functionalized imidazolium, pyridinium, and quaternary ammonium as cations and chlorides and tetrafluoroborate, hexafluorophosphate, dicyanamide, and bis- (trifluoromethanesulfonyl)imide as anions have been prepared and characterized. The physicochemical properties such as spectroscopic, thermal, solubility, surface, electrochemical, tribological, and toxic properties were comparatively studied. The results showed that the incorporation of a CN group to cations could result in remarkable changes in these properties. The reason resulting in such remarkable differences in the properties may be attributed to the conformational changes in the imidazolium groups caused by the interaction between the CN group with other neighboring cations or anions and the enhancement in hydrogen-bonding interactions due to the incorporation of a CN group.

★★★☆☆ Zhang QH,Li ZP,Zhang J,et al. Physicochemical Properties Of Nitrile-functionalized Ionic Liquids[J]. J. Phys. Chem. B,2007,111(11):2864-2872.

A novel series of ionic liquids (ILs) based on N-alkyl- -caprolactam as cations [Cn-CP]+ (Cn ) alkyl with different numbers of C atoms; n ) 6, 8, 10, 12, 16, or 18) containing toluene-p-sulfonate [TS]- and methanesulfonate [MS]- as anions have been synthesized via a one-step atom-economic reaction. Characterizations of these ILs by differential scanning calorimetry, polarizing optical microscopy, variabletemperature powder X-ray diffraction, etc., were conducted. The results showed that the caprolactambased ILs (n≥8) were enantiotropic thermotropic liquid crystals, except for C18-CPMS (monotropic), and displayed smectic A phases. Some properties, such as higher transition enthalpies (e.g., ΔH=83.1 kJ/mol for C18-CPTS), higher specific heat capacities (e.g., Cp=2.85 J/g·K for C16-CPTS) and higher heat storage densities (e.g., sensible heat storage density Es=262.8l MJ/m3 for C16-CPTS; latent heat storage density El=146.0 MJ/m3 for C18-CPTS), were observed. Fluorescence measurements showed that the homologous Cn-CPTS ILs exhibited strong fluorescence behavior. Finally, the test of acute toxicity toward rats showed that these new ILs were less toxic than the popular [BMIm]BF4 IL.

★★★★☆ Yang J,Zhang QH,Zhu LY,et al. Novel Ionic Liquid Crystals Based On N-alkylcaprolactam As Cations[J]. Chem. Mater.,2007,19:2544-2550.

Selective synthesis of carbamates from amines and dimethyl carbonate were studied in the presence of various ionic liquids as catalysts. The –SO3H-functionalized ionic liquid was found to be the most active catalyst among the applied ionic liquids, and nearly 100% conversion and 95% selectivity were achieved when using 1,6-hexanediamine as reactant. The acid functional ionic liquid catalyst system is also readily separable and reusable after reaction.

Keywords: Green chemistry; Ionic liquid; Carbamates; Amine; Non-phosgene

★★★☆☆ Zhou HC,Shi F,Tian X,et al. Synthesis Of Carbamates From Aliphatic Amines And Dimethyl Carbonate Catalyzed By Acid Functional Ionic Liquids[J]. Journal Of Molecular Catalysis A: Chemical,2007,271:89-92.

The solubilities of C2H4 and CO2 and the interactions of polar and nonpolar solutes with the novel ionic liquids (ILs) 1-butyronitrile-3-methylimidazolium bis(trifluoromethylsulfonyl) imidate (CpMIm[NTf2]), 1-butyronitrile-2,3-dimethylimidazolium bis(trifluoromethylsulfonyl) imidate (CpMMIm[NTf2]), 1-butyronitrile-3-methylimidazolium dicyanamide (CpMIm[N(CN)2]), 1-butyronitrile-2,3-dimethylimidazolium dicyanamide (CpMMIm-[N(CN)2]), 1-butyl-3-methylimidazolium palmitate (BMIm[n-C16H33COO]), and 1-butyl-3-methylimidazolium stearate (BMIm[n-C18H35COO]) were studied by gas chromatography at infinite dilution at T ) (303.15, 313.15, 323.15, and 333.15) K. Henry’s law constant kH of C2H4 and CO2 gas, infinite dilution activity coefficient γ∞, molar enthalpies of solution ΔsolH∞, and partial molar excess enthalpies of solution ΔHE∞ and of Gibbs energies ΔGE∞ were determined for polar and nonpolar solutes in these novel ILs. Compared with the 1,3-dialkylimidazolium ILs, cyano functional group substitution on the alkyl chain results in a remarkable decrease of the interactions of hydrocarbons. BMIm[n-C16H31OO] and BMIm[n-C18H35OO] demonstrate strong solubilization for both polar and nonpolar solutes. Straight lines of ln Vg versus 1/T and ln γ∞ versus 1/T were obtained for the majority of solutes in the temperature range. BMIm[NTf2] and 1-octyl-3-methylimidazolium tetrafluoroborate (OMIm[BF4]) show much better solubility for thiophene and are better solvents for the separations of thiophene from hydrocarbons.

★★★☆☆ Zhang J,Zhang QH,Qiao BT,et al. Solubilities Of The Gaseous And Liquid Solutes And Their Thermodynamics Of Solubilization In The Novel Room-temperature Ionic Liquids At Infinite Dilution By Gas Chromatography[J]. J. Chem. Eng. Data,2007,52:2277-2283.

Based on the diversity of ionic liquids, i.e. tunable structure and physicochemical properties, a series of functional ionic liquids and palladium complexes were investigated, and a highly effective catalyst system, Pd(phen)Cl2-BAcImPF6 ionic liquid (phen = 1,10-phenanthroline; BAcIm = 1-butyl-3-acetic acid-imidazolium), was developed for the reductive carbonylation of nitrobenzene to give the corresponding carbamate with higher than 90% of conversion and selectivity at 150 ◦C and 6MPa carbon monoxide. The high catalytic performance is attributed to the acidic function of the BAcImPF6 ionic liquid and the interaction between Pd(phen)Cl2 and the ionic liquid to form the catalytically active palladium complex Pd(phen)2(PF6)2.

Keywords: Nitrobenzene; Carbon monoxide; Carbonylation; Ionic liquids; Palladium complex

★★★☆☆ Shi F,He YD,Li DM,et al. Developing Effective Catalyst System For Reductive Carbonylation Of Nitrobenzene Based On The Diversity Of Ionic Liquids[J]. Journal Of Molecular Catalysis A: Chemical,2006,244:64-67.

Esterification of tert-butanol by acetic anhydride, a typical acid–base catalytic reaction, was conducted with excellent selectivity and high yield in a neutral ionic liquid [BMIm]BF4 (1-butyl-3-methylimidazolium tetrafluoroborate). Many other tertiary alcohols could also be successfully converted to the corresponding esters in [BMIm]BF4. Separation of product and recovery and reuse of ionic liquid are all convenient in this system. Here, the need for catalysts is avoided through the use of catalytically active ionic liquids as solvents.

Keywords: [BMIm]BF4; Esterification; Tertiary alcohol; Acetic anhydride

★★★☆☆ Duan ZY,Gu YL,Deng YQ. Neutral Ionic Liquid [bmim]bf4 Promoted Highly Selective Esterification Of Tertiary Alcohols By Acetic Anhydride[J]. Journal Of Molecular Catalysis A: Chemical,2006,246:70-75.