新型四硫代富瓦烯衍生物的合成及其性质的研究

合成了3个新的含有卤素取代基的四硫代富瓦烯衍生物及6个新的相关化合物。利用溶液的电子吸收光谱对四硫代富瓦烯衍生物的性质进行了研究。研究结果表明, 四硫代富瓦烯衍生物的分子中π轨道之间的能级差较小, 因而分子具有较高的稳定性。     

磁载纳米TiO2光催化剂的制备及其光催化性能研究

采用肼((NH2)2*H2O)还原硝酸铁(Fe(NO3)3)法制备纳米级磁基体(Fe3O4), 以聚乙二醇对其表面进行改性, 通过溶胶-凝胶法制得TiO2/Fe3O4磁载纳米TiO2光催化剂, 并用于光催化降解橙黄-II, 对其活性进行评价. 结果表明 TiO2/Fe3O4光催化剂的降解率在第一次使用时与纯TiO2相近, 三次循环使用后, 仍能保持较高的催化活性. 催化剂的最佳用量为4 g/L, 在酸性和碱性环境中均能保持很好的催化活性.     

室温离子液体EMIES的标准生成焓

在(298.15 ±0.01) K下用转动弹热量计测定了离子液体硫酸乙酯-1-甲基-3-乙基咪唑(EMIES)及合成它的原料1-甲基咪唑的恒容燃烧热,通过计算得到它们的标准燃烧焓 分别为(－2671±2) 和(－286.3±0.5) kJ·mol－1;标准生成焓 分别为(－3060±3) kJ·mol－1和(－2145±4) kJ·mol－1.结合文献上硫酸二乙酯的标准生成焓数据,得到了合成离子液体EMIES的反应热(－102.3±1.0) kJ·mol－1,与合成实验中观察到的强烈放热现象是一致的.根据离子液体EMIES的热容数据,计算了不同温度下EMIES的标准生成焓.     

Solid-phase Synthesis of-Haloaldehydes from Polymer-supported 4-(Phenylseleno)morpholine

Polymer-supported reagents for organic synthesis are enjoying a renewed popularity with the emergence of combinatorial chemistry in recent years1. 4-(Arylseleno)morpholines formed in situ are useful -seleno-introducing reagents for saturated aldehydes2. -Sele- noaldehydes, as a frequently used intermediates, can be converted into -haloaldehydes by halogenating reaction3. However, organic selenium reagents always have a foul smell and are quite toxic, which is often problematic in organic sy…     

Preparation and Properties of Urease Immobilized onto Glutaraldehyde Cross-linked Chitosan Beads

Urease was immobilized onto the glutaraldehyde cross-linked chitosan beads that were prepared under microwave irradiation. The activity and the yield of activity of immobilized urease was 10.83 U/g B and 47.7%, respectively. The conditions of urease immobilization were optimized. The properties of the immobilized urease were investigated and compared with that of the free enzyme.     

Overlapping spectra resolution using non-negative matrix factorization

Non-negative matrix factorization (NMF), with the constraints of non-negativity, has been recently proposed for multi-variate data analysis. Because it allows only additive, not subtractive, combinations of the original data, NMF is capable of producing region or parts-based representation of objects. It has been used for image analysis and text processing. Unlike PCA, the resolutions of NMF are non-negative and can be easily interpreted and understood directly. Due to multiple solutions, the original algorithm of NMF [D.D. Lee, H.S. Seung, Nature 401 (1999) 788] is not suitable for resolving chemical mixed signals. In reality, NMF has never been applied to resolving chemical mixed signals. It must be modified according to the characteristics of the chemical signals, such as smoothness of spectra, unimodality of chromatograms, sparseness of mass spectra, etc. We have used the modified NMF algorithm to narrow the feasible solution region for resolving chemical signals, and found that it could produce reasonable and acceptable results for certain experimental errors, especially for overlapping chromatograms and sparse mass spectra. Simulated two-dimensional (2-D) data and real GUJINGGONG alcohol liquor GC-MS data have been resolved soundly by NMF technique. Butyl caproate and its isomeric compound (butyric acid, hexyl ester) have been identified from the overlapping spectra. The result of NMF is preferable to that of Heuristic evolving latent projections (HELP). It shows that NMF is a promising chemometric resolution method for complex samples.     

Oxidation of isobutane catalyzed by vanadyl, copper and cesium substituted H3PMo12O40

Effects of Cs⁺, H⁺ and Cu²⁺ counterions in the vanadium containing heteropoly compounds Cs_xH_1-xVO[PMo₁₂O₄₀] and Cs_yH_0.5-yCu_0.25VO[PMo₁₂O₄₀] on the catalytic oxidation of isobutane and characterization by TGA, IR and ESR spectroscopies are reported. A high selectivity of 76% for methacrylic acid and methacrolein together has been obtained with Cs_0.75H_0.25VO[PMo₁₂O₄₀] catalysts at a reactivity of 5.3x10^-1 mmol/h cm³.     

脂肪族酰胺二元醇的合成与表征

以ＤＬ－乳酸、ε己内酯及乙二胺和己二胺为原料合成了四种结构的脂肪族酰胺二元醇，并用ＩＲ，＾１ＨＮＭＲ，ＤＳＣ对酰胺二元醇的结构进行了表征。     

Reversed stereoselectivity in iodohydroxylation of allenyl sulfides. An efficient synthesis of (Z)-3-organosulfur-2-iodo-2-propenols

[reaction: see text] It is observed that the iodohydroxylation of 1,2-allenyl sulfides with I(2) and water in aqueous acetone showed Z-selectivity, which is opposite to that of the iodohydroxylation of 1,2-allenyl sulfoxides.     

Three New Serratane Triterpenoids from Phlegmariurus squarrosus

Three new serratane triterpenoids, (3α,14α,15α,21α)‐3,14,15,21,29‐pentahydroxyserratan‐24‐oic acid ( 1 ), (3α,21β)‐serrat‐14‐ene‐3,21,24,30‐tetraol ( 2 ), and (3α,21α)‐serrat‐14‐ene‐3,21,24,29‐tetraol ( 3 ), were isolated from Phlegmariurus squarrosus, together with eight known compounds. Their chemical structures were elucidated on the basis of in‐depth spectroscopic analyses.