Pre-reduced Activated Carbon-Supported Molybdenum-Based Catalysts for the Production of Mixed Alcohols from Synthesis Gas

Unsupported or supported Mo-based catalysts have been widely employed in petroleum industry, for hydrotreating^[1],and for the production of hydrocarbons^[2] and alcohols_[3] by hydrogenation of CO (or CO₂). Oxides, such as alumina, silica, silica-alumina, are commonly used as the supports for these purposes. Carbon-supported materials have been claimed to have potential advantages over oxide-supported ones, such as lower tendency of carbon deposition^[4], less dehydration and thus less secondary reactions. Here we present results on mixed alcohol synthesis over H₂-prereduced C-supported Mo-based catalysts.     

Asymmetric Borohydride Reduction of Acetophenone Catalyzed by Chiral Salen-Co(Ⅱ) Complex Using Sodium Borohydride

Development of efficient catalytic asymmetric reactions is the most challenging task in current synthetic chemistry; much effort has been devoted to create the chiral metal complexes of asymmetric catalysis. In the last two decades' many brand-new ligands had been synthesized and their combination with various metal ions has been applied in asymmetric catalysis. However, most ligands have only narrow applications and their use is limited to some reactions. Exceptionally, a few ligands and their metal complexes such as binaphthol, semicollin,and binap show wide applicability. Chiral salen ligand is one of such ligands and their metal complexes are now used as the catalysts for a variety of asymmetric reactions such as epoxidation^[1], aziridination^[2], cyclopropanation^[3], Diels-Alder reaction^[4], asymmetric transfer hydrogenation of aromatic ketones^[5] and kinetic resolution of racemic epoxides^[6] and so on.     

The Structure and Properties of Mesoporous TiO2 Film Photocatalyst

As a good photocatalyst, TiO₂ has a promising prospect in environmental purification^[1]. Due to the technical problem for the separation of dispersed TiO₂ nanosized catalyst, TiO₂ film photocatalyst has become a better choice for TiO₂ photocatalyst used in fluid^[2]. Because TiO₂ thin film photocatalyst has small surface area, the catalytical activity was very low. It was an effective way to use mesoporous TiO₂ film with high surface area as photocatalyst. The structure and properties of mesoporous TiO₂ film was studied here.     

A multi-color and white-light emissive cucurbituril/ terpyridine/ lanthanide supramolecular nanofiber

The enhanced lanthanide white-emission in solid by cucurbituril-based supramolecular assembly may provide a new strategy for smart light-emitting materials.     

Study on the Dye-Doped Funcionalized Silica Nanoparticles for The Recognition of SmIgG+B Lymphocytes

The development of sensitive non-isotopic detection sys tem for biological and medicinal applications, such as single cell analyse, DNA sequence, clinical diagnose etc., has driven nanomaterials more towards cell biology and ultrasensitive immunoassay^[1]. Semiconductor nanoparticles have been used for coupling biomolecules but suffer from some disadvantages including poor solubility in water, blinking properties or low quantum yields^[1,3,4]. In this paper, we developed a novel dye-doped functionalized silica nanoparticles and used for detection of SmIgG⁺ B lymphocytes.     

Synthesis of Alkyl Bromide by the Method of Phase Transfer Catalysis

Phase transfer catalysis is one of the most active techniques used in organic synthesis^[1]. The process is versatile, fast, inexpensive, involves smooth work-up, give good yield and needs less drastic condition compared to conventional methods of synthesis. The technique has a very broad scope of application^[2], surprised, few are have been devised for synthesizing alkyl bromides. Alkyl bromides are important materials in organic synthesis and in agricultural chemical purpose, as well as widely used in the oil field gas exploration and water treatment^[3].     

Electrochromic Properties of Rhodium Oxide Films Prepared by Sol-gel Method

Electrochromic materials have been extensively investigated for their significant potential in information display, automotive, sensor and smart windows^[1]. Many studies have been carried out on the inorganic electrochromic materials, such as WO₃, MoO₃, NiO_x and so on^[2]. In this paper, We first report the electrochromic behavior of rhodium oxide film prepared by sol-gel method on transparent conductor substrate. The film exhibited reversible two color (from bright yellow to dark green) electrochromic behavior with satisfactory contrast at anodic and cathodic forms when the applied potential was reversed successively.     

Template Synthesis of Nano-structured Materials for Electrochemical Applications

As an important preparation method of nano-structured materials, template synthesis^[1] attracted great interests in recent years. Different kinds of template such as anodic porous alumina, polymer and nano-channel glass templates have been widely studied. Compared with other templates, the size of holes in the porous alumina template can be easily controlled by properly adjusting the condition of anodization. In addition, Nano-structured material prepared from the template also provides an ideal system^[2] to investigate the effects of size of materials toward electrode's performance. In this paper, various nano-structured materials such as spinel LiMn₂O₄ and carbon nanotubes by using porous alumina template have been prepared and characterized.     

Chiral Resolution of l,l'-Binaphthalene-2, 2'-Diol and its (-)-Menthyl Chloroformate derivatives by HPLC with Urea Derivative as Chiral Stationary Phase

Optically pure l,1'-binaphthalene-2,2'-diols are very useful compounds for various application^[1] such as catalyst ligands for asymmetric synthesis, the starting materials for other chiral binaphthyl catalysts and resolving agents for racemic compounds. Consequently, the preparation of optically pure l,l'-binaphthalene-2,2'-diols are of current interest Recently, new methods of resolution of racemic l,1'-binaphthalene-2,2'-diols utilizing (-)-(lR)-menthyl chloroformate as the derivatization agent have been developed^[2,3]. To determine the optical purity of these 1,1'-binaphthalenes, it is necessary to develop a convenient and reliable method for the detection of each stereoisomers.     

A SIMPLE,EFFICIENT AND NEW METHOD FOR PREPARING AZO UREAS

Azo compounds are widely utilized as dyes and analytical reagents.They can also be used as materials for non-linear optics and for storage optical information in laser dish^[1]. Recently, many noteworthy studies have shown that azobenzene derivatives possess excellent optical memory and photoelectric properties^[2]. The preparation of ordinary azo compounds has been described in many references. However, those compounds generally bear alkyl or aryl groups on both sides of the azo linkage (-N=N-).     

The Chlorination of O-Alkyl S-Alkyl(aryl) Thiophosphoric(-nic) Acid Derivatives with Phosphorus Oxychloride——A New Convenient Method for Synthesis of Chiral S-Alkyl(aryl) Thiophosphoro(-no) Chloridates

In our laboratory, the isomerization/chlorination of a variety of O,O-dialkyl phosphoro(-no)thionates 1 with phosphorus oxychloride have been systematically studied. It was found that when R' equals aryloxy^[1], alkylthio^[2], arylthio^[2], dialkylamino^[3], phenyl^[4], methyl^[5],and nitrogen heterocyclic group^[6] in 1,respectively, this reaction can proceed smoothly and gives the desired products ² and ³. Hence, it provides a general synthitic method for S-alkyl thiophosphoro(-no)chloridates, especially for the asymmetric ones.     

Sulfate/Bisulfate Adsorption at the Pt(111) Surface

The cyclic voltammograms of Pt(111) electrode in sulfuric acid solutions display an anomalous wave and a unique butterfly peak. Extensive studies have been made to investigate these unique features since the advent of the flame annealing technique in 1980^[1]. Yet, the assignment of these features to sulfate^[2] or bisulfate^[3] adsorption is still full of controversy and no conclusive evidence has been reported in the literature.     

Synthesis of Silica Hollow Spheres with Diameter Around 50 nm by Anionic Surfactant

Silica hollow spheres(SHSs) have attracted great attention because of their low toxicity,low density,large surface area,high chemical and thermal stability,and surface permeability.They can be widely applied in storage[1],catalysis[2],drug delivery[3,4],low-dielectric-constant materials[5],low-refractive materials[6-8],and so on.Up to now,there have been various methods to produce SHSs.Inorganic[9] or organic particles[10],such as polystyrene or calcium carbonate,were used as hard templates to create hollow cavities.However,the multistep synthetic process and the lack of structural robustness of the shells upon template removal process weaken their application.Soft templates,including oil-in-water emulsions[1],[2],vesicles[13],micelle[14,15] and gas bubbles[16],are applied widely.     

A Density Functional Study of Small Tungsten Clusters Adsorbed on the MgO(001) Surface

Metal atoms, clusters, and thin films supported on surfaces of metal oxides have attracted a lot of attention not only due to the fundamental interest in the basic nature of metal-oxide interfaces, but also because of their numerous practical applications in catalysis, microelectronics, as coatings for corrosion protection and gas-sensors^[1,2]. In this paper, adsorption of tungsten clusters W_n (n=l-4) on the ideal MgO(001) surface has been studied computationally at the density functional (DF) level of theory with the help of a scalar-relativistic variant of the linear combination of Gaussian-type. orbitals density functional method (LCGTO-DF)^[3] as implemented in the program PARAGAUSS for parallel computing^[4]. Stucture and energetic features of the adsorption complexes W_n/MgO(001) have been analyzed. The gradient-corrected Becke-Perdew functional was used self-consistently. Spin-polarized calculations were performed in order to account for the possible open-shell nature of the metal clusters.     

“Approximation”-Novel Methodology to Identify the Active Components from Compounds Library

Combinatorial chemistry has been regarded as one of the most efficient method in medicinal chemistry. Identification of active compounds from compounds library is one of the main steps of combinatorial chemistry. Many approaches have been developed for this purpose, such as deconvolution^[1] positional scanning^[2], SURF^[3],orthogonal library^[4], indexed library^[5], core molecule library^[6] etc. Actually, all the methods are based on the rule of determining the structure of "Active Components" or "Active Compounds"(AC) from "Active Compounds Library"(ACL) by identifying "Active Building Blocks"(ABB). In this way, more efficient method named "Approximation" was developed by reducing the ABB by half in every steps, which was depicted as below by taking "8ҿ8" library as a example.     

A New Chemiluminescence Method for the Determination of Pyrogallol

Pyrogallol(Py) is a chemiluminescence(CL) reagent with a low emission efficiency. The pyrogallol structural group is also found in molecules of many important natural and synthetic confounds, such as gallic acid humic acid and pyrogallol red. Studies of the metablism of phenolic compounds requires the development of specific and sensitive methods for the determination of pyrogallol. HPLC^[1], spectrophotometry^[2] and CL^[3-7] have been used to determined polyphenols, but these methods are complicated or low sensitivity.In this paper, a new Chemiluminense(CL) analytical method for determination of Py was established.This method is more sensitive than those methods reported in the literature^[3-7].     

Water-alcohol Separation by Pervaporation through Zeolite Modified Poly(amidesulfonamide)s (PASAs)

A series of poly(amidesulfonamide)s (PASAs) which have been synthesized in our laboratory possess good membrane fabrication properties^[1]. The potential use of these membrane materials in RO, UF and PV were demonstrated^[2,3]. Reminiscent to the PV performance of other glassy polymers, most of these materials exhibit a fairly high separation factor albeit a permeation flux below 35 g m^-2 h^-1 in the PV separation of aqueous alcohol mixtures. To have a real application prospect in PV, the permeation flux through the membranes has to e further improved. The present work represents our effort to upgrade the separation characteristics of PASAs by blending with inert hydrophilic zeolites. Three types of PASAs (structure shown in Figure 1) were selected to be fabricated by blending different amount of zeolite NaA or NaX. The zeolite filled membranes were characterized by SEM, IR spectroscopy, sorption measurements and wide-angle X-ray diffraction. By adding proper amount of NaA into the polymer casting solutions, the resultant zeolite filled membranes exhibited improvement in both selectivity and permeability in the separation of 10% aqueous solutions of ethanol, propan-l-ol and propan-2-ol, as compared to the zeolite free membrane (Table 1).     

Photochromic Properties of New Dithienylethene Copolymer

Photochromic molecular switches can be important memory media for optical information processing and storage as long as their thermal stability and photo-fatigue resistance met certain criteria. Among many photochromic materials, heterocyclic diarylethenes have displayed desirable optical switching characteristics. Specifically, bisthienylethene (BTE)-based photochromic switches have demonstrated high sensitivity and rapid response as well as thermal- and photostability^[1,2]. It has been shown that various BTEs can undergo ca.l0^[4] cycles before significant evidence of fatigue^[3]. It is important that molecules with otherwise improved switching characteristics retain this level of fatigue resistance. For example, the improved characteristics include that the absorption of close form of photochromic materials should be shifted to shorter wavelength region due that semiconductor laser shift to short wavelength are developing trend for high density information storage. Also, fatigue may be different in the solid state than in solution. In general, precedent photochromic polymers consisted of photochromic molecules either dispersed in a matrix or covalent grafted onto the polymer main chain.     

Fibre-Optic pH Probe Based on the Use of An Immobilized Amino Fluoresecein Indicator

Optical sensors can offer advantages over electrochemical sensors with respect to reduced interferences and ease of use for remote sensing^[1]. The first fiber optic pH sensor was developed for in vivo measurements by Peterson et al^[2]. This sensor relates pH to the absorbance of the base from of an immobilized dye. Subsequently, a pH sensor based on the fluorescence of immobilized fluoreseinamine was reported. The sensor involves immobilizing the amino fluoresecein (AF) complex within a porous sol-gel-processed film. Sol-gel process has many advantages as a method of immobilization^[3]. At ambient temperature, it allows the fabrication of a tough, inert, porous glass material with a high surface area. Sol-gel technology provides a viable approach to prepare stable, optically transparent host matrices for the design of materials for sensor, optical, chromatographic^[4], and catalytic applications. Alternatively, organosilicon precursors of the general formula can be hydrolyzed and co-condensed with tetraethoxysilane to form an organic-inorganic hybrid. An aliquot of the resultant sol can be spin cast or dip coated on a planar substrate to form a thin film.     

Syntheses of 3-[5-Methyl-1-(4-Methylphenyl)-1,2,3-Triazol-4-yl]-6-Substituted-s-Triazolo[3,4-b]-1,3,4-Thiadiazoles

1,2,3-Triazole derivatives have been reported as inhibiting tumor proliferation, invasion, and metastasis^[1]. The fused l,3,4-triazolo[3,4-b]-1,3,4-thiadiazoles derivatives show various biological effects such as antifungal^[2], antibacterial, hypotensive and CNS depressant activities^[3]. We have reported several 6-aryl-3-[5-methyl-1-(4-methylphenyl)-1,2,3-triazol-4-yl]-s-triazolo[3,4-b]-1,3,4-thiadiazoles in the previous paper^[4]. The novel 6-aryl-3-[5-methyl-1-(4-methylphenyl)-1,2,3-triazol-4-yl]-s-triazolo[2,4-b]-1,3,4-thiadiazoles 6a-j have been synthesized by the condensation of 4-amino-5-mercapto-3-[5-methyl-1-(4-methylphenyl)-1,2,3-triazol-4-yl]-s-triazole 5 with various aromatic carboxylic acids in the presence of phosphorus oxychloride. The mercaptotriazole 5 was prepared from 4,the latter being prepared from 1 throng 2 and 3. The title compounds 6 were depicted in scheme 1. The structures of these compounds were established by elemental analysis, NMR, MS and IR techniques.