Reduction of Elemental Selenium by Samarium Diiodide: the Synthesis of Dithiodiselenides and Dithioselenides

Selenium is an essential element in living organism. It is reported that the selenosulfides have been transported in vivo in glutathione or coenzyme-A1. It is also discovered in low concentration in garlic2. In organic synthesis, selenosulfides are useful intermediates3. Several methods for the formation of sulfur-selenium bond have been reported. For example, the compounds including S-Se bond were prepared by chloroamination of thiols and selenols4; by heating the selenocyanate with thiols5…     

Preparation and Properties of Oxidized Graphite Anode Doped with Metal Ion for Lithium Ion Batteries

During the past years, there have been a lot of interests in the research of carbonaceous material as anode in lithium ion batteries1-3. Among them, natural graphite seems to be the most promising candidate for anode in lithium-ion batteries in terms of economy. Figure 1 The effect of Different Contents Figure 2 The Effect of Reacting Timeof Mixed Acid on Interlayer Distance On Interlayer DistanceHowever the raw natural graphite cannot be used for commercial purposes, because during proc…     

Enantioselective Alternating Copolymerization of Propylene with Carbon Monoxide Using Cationic Palladium-Chiral Diphosphine Catalyst

Alternating copolymerization of (-olefins with carbon monoxide (CO) catalyzed by cationic palladium-chiral ligand complexes is of great interest due to the potential use of the resulting polymer as a new material1. Recently, enantioselective alternating copolymerization of CO with styrene has been reported by us using PdCl_2-CuCl2-chiral phosphine catalyst2. Here, we first report enantioselective alternating copolymerization of CO with propylene (P) using [(DDPPI)Pd(CH3CN)4](BF4)2 as …     

An Improved Method of Total Synthesis of 2-Methoxypodocarpane-8,11,13-triene

12-Methoxypodocarpane-8,11,13-triene 1 is the key intermediate for synthesis of some important diterpenoids, such as Ferruginol 21, 6,7-dehydroferruginol 31, sugiol 42, 5-epixanthoperol 53 etc. These compounds posses significant bioactivities, such as fungicidal1, antimicrobial1 and cytotoxic activity2. Some methods of synthesis of the title compound 1 were reported, but the process is laborious and the yield is low. In connection with our effort to discovery and develop new anti-HIV drugs, …     

Effects of the Specific Area and the Thermal Stability of a Polymer on the Catalytic Activities of Polymer Immobilized Co-Pd Catalysts by SAMI

Co-Pd bimetallic catalysts immobilized with four kinds of resins with different specific areas were prepared by means of the solvated metal atom impregnation (SMAI) method. The results of the XRD and the magnetic measurement showed that as the specific area of the resin increased, the particle sizes of Co and Pd on the catalysts with the same metal content decreased, so the catalytic activity of the catalysts for the hydrogenation of diacetone alcohol as well as the reduction of oxygen on the fuel cell electrode increased. Below 140 , the conversion of diacetone alcohol increased as the reaction temperature increased, and above 140 , the conversion decreased because of the rupture of the resin.     

Synthesis and Structure of an Interlock Network Frame of Cobalt(Ⅱ) Coordination Polymer {[Co(azpy)_2(NCS)_2]·1/4EtOH·1/2H_2O}_n (azpy=4,4′-Azobispyridine)

A compound {[Co(azpy)_2(NCS)_2]·1/4EtOH·1/2H_2O}_n(1), where azpy=4,4'-azobispyridine, was synthesized and characterized by means of IR, TGA-DTA, magnetic susceptibility and X-ray single crystal diffraction. It consists of two independent sets of fully interlocked two-dimensional networks with the dihedral angle 61.7°, organized in parallel stacks of the sheets which are made of edge-shared [Co(Ⅱ)]_4 squares separated by 0. 9062nm, and defined size rhombic channels. The thermal gravimetric analysis indicates that the framework is stable up to 198℃. The variable-temperature magnetic susceptibility measurements indicated that there is a weak antiferromagnetic interaction between the cobalt(Ⅰ) ions in the complex (1).     

Bioinformatics Assisted Gene Discovery and Annotation of Human Genome

IntroductionBioinformatics is coming with Human GenomeProject(HGP) . With the explosions of sequence,structural and other information available ,bioinformatics is playing an increasingly large rolein the study of fundamental biomedical problems.At present and in the near future,it is the mainchallenge for bioinformatists to make gene dicoveryand annotation of human genome sequences whenthe vast amount of data is produced by the highthroughput genome sequencing in a large scale andautomated m…     

Surface Activities of Calix[4] resorcinarenes Bearing Four Hydrophobic Chains and Its Sol ubilization for Organic Compounds

ＩｎｔｒｏｄｕｃｔｉｏｎＩｎｃｌｕｓｉｏｎｃｏｍｐｏｕｎｄｓｈａｖｅｂｅｅｎｎｏｔｅｄｉｎｒｅｃｅｎｔｙｅａｒｓａｎｄｒｅｓｏｒｃｉｎｏｌ ｔｙｐｅｃａｌｉｘ [4 ]ａｒｅｎｅｈａｓｂｅｅｎｓｔｕｄｉｅｄｆｏｒｔｈｅｉｒｉｎｃｌｕｓｉｏｎａｂｉｌｉｔｉｅｓｂｙＳｃｈｅｉｄｅｒａｎｄＢｕｇｌｅｒｅｔａｌ[1— 3] .Ｔｈｅｐｏｌｙｏｌｍｏｉｅｔｉｅｓｉｎｃａｌｉｘ[4 ]ｒｅ ｓｏｒｃｉｎａｒｅｎｅｆｏｒｍｒｉｇｉｄｈｙｄｒｏｇｅｎ ｂｏｎｄｉｎｇｎｅｔｗｏｒｋｓ[4 ] ,ａｎｄｃａｌｉｘ [4 ]ｒｅｓｏｒｃｉｎａｒｅ…     

A New Organo-templated Layered Zincophosphate Synthesized from a Solvothermal System Containing Racemic1,2-Diaminopropane

IntroductionSince Wilson and co- workers successfullysynthesized three- dimensional microporousaluminophosphates (Al PO4 - n ) [1] in the 1 980 s,much attention has been focused on the explorationof1 - D chain,2 - D layer and3 - D open- frameworkmetal phosphates from aqueous or non- aqueoussystems.The number of metals incorporated intothe frameworks of these materials is continuouslyincreasing and the metals include Be[2 ] ,Ga[3] ,In[4 ] ,Sn[5] ,Sb[6 ] ,and the transition metals Zn[7] ,Ni…