Effect of Co-solvent on the Palladium Catalyzed Alkoxycarbonylation of Allyl Bromide in Supercritical CO_2

We have studied the palladium-catalyzed alkoxycarbonylation of allyl bromide in supercritical (sc) CO2 and found the reaction rate in sc CO2 was lower than those in some organic solvents1. The possible reason was the lower solubility of sc CO2 for the palladium catalyst. As an effective approach to improve the solubility of varieties of solutes, cosolvent such as ethanol has been widely used in the sc CO2 extraction2,3. Based on the above consideration, we chose several organic reagents…     

Dioxygen Affinities and Catalytic Oxidation Performance of Cobalt (II)Complexes with N-Aryl Hydroxamic Acid

It is well known that the study on biomimetic oxygen carriers not only has important theoretic significance to discover the mechanism of reversible bonding, activating oxygen as well as the oxidation reaction in organism, but also has potential application in separating oxygen from air and realizing the high efficiency and selectivity of catalytic oxidation reaction under a mild condition1. Metal- porphyrin and metal- phthalol- gaunine have been extensively used as biomimetic oxygen carriers u…     

电热蒸发进样—等离子体原子发射光谱中钒和钛的蒸发机理研究

自1974年Nixon报道钽丝电热蒸发作为ICP-AES进样技术以来,这一技术已引起了人们的极大兴趣,受到越来越广泛的重视。电热蒸发(ETV)-ICP-AES是一种将蒸发和激发分步进行的联用技术。石墨是目前普遍使用的蒸发器材料。然而,在高温下某些元素和石墨材料可以发生碳化反应,形成热稳定的碳化物,使分析物蒸发不完全或根本不蒸发,从而影响分析结果的灵敏度和准确性。为了解决这一问题,我们曾提出了以聚四氟乙烯(PTFE)悬浮体为氟化剂,氟化辅助ETV-ICP-AES直接测定粉煤标样中钒和钛的新方法,其检出限     

羟基化合物及其葡醛酸苷化学结构与RP—HPLC保留行为相关性研究

采用体外孵育生物合成方法获得羟基化合物葡醛酸苷系列化合物，并对其反相高效液相色谱保留行为及底物与其葡醛酸结合物保留行为相关性进行了研究，建立了相应的结构－色谱保留行为相关性方程及葡醛酸苷类代谢物保留行为的预测方法。将ＱＳＲＲ研究扩展到药物代谢物领域，对药物Ⅱ相葡醛酸化代谢产物的ＨＰＬＣ分析提供了帮助。     

新型稀土杂多蓝的合成及其抗艾滋病病毒(HIV-1)活性和毒性研究

合成Keggin结构钨硅、钨锗、钨磷、钨坤两电子及四电子稀土钐盐杂多蓝，铈量滴定及元素分析方法确定了化合物的还原电子数及化学组成，采用IR，UV－Vis,^183W NMR和ESR等对其结果进行了表征，在人T淋巴MT－4内，对合成的化合物进行了系统的抗艾滋病毒（HIV－1）活性及毒性测定，发现Keggin结构钨硅、钨锗四电子稀土钐盐杂多蓝具有较强的抗HIV－1活性，其中钨锗酸钐四电子杂多蓝（代号HPBR－2）具有较高的治疗指数。     

Crystal Structure, Thermal Stability and Luminescence of Coordination Polymer [Cd（BBP）（p-PDOA）]n

Hydrothermal reaction of Cd（NO3）2·4H2O with bbp and p-PDOAH2 at 140 ℃ yielded a novel 1D cadmium（Ⅱ） coordination polymer, [Cd（bbp）（p-PDOA）]n （bbp=2,6-bis（benzimidazol-2-yl）pyridine, p-PDOA=p-phenylenedioxydiacetate dianion）, in which CdN3O4 pentagonal bipyramids were linked by p-PDOA ligands in a bis-bidentate mode to construct a zigzag chain with the adjacent Cd…Cd distance of 1.14（1） nm, There exists a 2D supramolecular network linked by π-π stacking with a face-to-face distance of 0.35（1） nm between the 2,6-bis（benzimidazol-2-yl） pyridine ligands and hydrogen-bonding interactions （0.27（4） nm）. A 3D supramolecular network was further constructed by these non-covalent interactions between the zippers. The TG/DTG showed that its chain skeleton was thermally stable up to 389 ℃ and the blue fluorescent emission of the complex was determined at 428 nm in a solid state with its long decay lifetime of 7.24 ns.     

Synthesis and Crystal Structur of (4,4''-H2bipy)[CdBr4]·H2O

The title compound (4,4'-H2bipy)[CdBr4]·H2O 1 has been synthesized via hydrothermal reaction and characterized by X-ray diffraction. The crystal belongs to monoelinic,space group P21/c with a=8.260(3), b=23.926(7), c=9.774(2) (A), β=106.777(9)°,C10H12Br4CdN2O, Mr=608.26, V=1849.4(9)(A)3, Z=4, Dc=2.185 g/cm3, S=1.005, μ(MoKα)=9.814 mm-1, F(000)=1128, R=0.0646 and wR=0.0989. The crystal structure analysis of 1reveals that the title compound features an isolated structure, based on discrete 4,4'-H2bipy moieties and lattice water molecules which are linked by hydrogen bonds together with tetrahedral cadmium atoms terminally coordinated by four bromine atoms.     

多缩乙二醇二苯醚与甲醛缩聚合成酚醛型聚合物假冠醚的研究

本文采用苯酚、多缩乙二醇二氯化物、多缩乙二醇等为起始原料,合成了九个多缩乙二醇二苯醚新单体,经甲醛聚合获得一系列聚合物假冠醚,并对它们的溶解性能、络合性能以及催化作用等进行研究。     

Theoretical Study on the Isomerization Mechanism of Enol Ester from 2-Acyl-1, 3-cyclohexanediones

The present paper employed density function theory to investigate two reaction pathways for isomerization of enol ester proposed by Yang(path a) and the present authors(path a), respectively. The base catalytic effects of solvent triethylamine on these two reactions were also evaluated. It is demonstrated that path B is more preferable than path a due to low barrier height for the rate-determining step.