氧化作用控制“四硫富瓦烯-蒽”二元体系的荧光开关行为

利用Wittig反应将高荧光量子产率的蒽基团通过双键连接在四硫富瓦烯单元上,合成了二元共轭体系化合物TTFan.在氧化作用的控制下,四硫富瓦烯单元的给电子能力降低,TTFan的荧光发射强度增大至原来的十几倍,实现了荧光的“off-on”过程.     

“A-C≡C-TTF-C≡C-A”型四硫富瓦烯衍生物的合成与性质研究

四硫富瓦烯及其衍生物是性能优良的电子给体.本文利用Sonogashira反应将吡啶基团连接在四硫富瓦烯单元上,合成了"A-C≡C-TTF-C≡C-A"型四硫富瓦烯共轭体系衍生物4,4′(5′)-二-(4-吡啶乙炔基)-四硫富瓦烯(TTF4N).吸收光谱、电化学和Pb2+配位键合研究表明,三键作为桥基能够有效实现分子内的电荷转移.金属Pb2+离子与吡啶基团的配位能够引起TTF4N的吸收光谱、核磁氢谱和电化学性质的显著变化.     

氧化还原荧光开关构建的新型高选择性多信号化学传感器的研究

2,3,6,7-四(2′-氰乙硫基)四硫富瓦烯在醇钠的作用下消除氰乙基生成四硫富瓦烯四硫盐,再与9-溴甲基蒽反应生成四(9-亚甲基蒽硫基)四硫富瓦烯,通过氧化还原法发现其荧光能够可逆地增强或减弱,因此它是一个新的氧化还原荧光开关。在多种金属离子中,该新型氧化还原开关只对Fe3+有识别性能,其荧光强度随Fe3+的量增大而增强,其他金属离子没有干扰。所以,它又是一种对Fe3+具有高选择性识别的荧光传感器。该文报告工作的新颖性已为安徽大学图书馆2009年4月30日出具的第2009006号《科技查新报告》所证实。     

四硫富瓦烯作为催化剂的研究进展

介绍了四硫富瓦烯作为自由基-极性交叉反应的催化剂的反应机理,以及四硫富瓦烯催化的自由基-极性交叉反应在四环生物碱等天然产物合成方面的研究进展,展望了其发展趋势。     

D-π-A型四硫富瓦烯衍生物的合成及其性能研究

作为很强的有机电子给体,四硫富瓦烯能够在低电位被可逆氧化,失去一个或两个电子生成相应的正一价阳离子自由基或正二价阳离子．近年来它在众多领域显示出日益重要的作用．本论文设计合成了一系列具有D-π-A和A-π-D-π-A结构的四硫富瓦烯 (TTF)衍生物,系统研究了它们在基态发生分子内电荷转移的可能,并利用外界刺激改     

带有3个四硫富瓦烯结构单元的三脚型电子给体化合物的合成

在DMF-MeOH体系中,2-氰乙硫基-3,6,7-三取代四硫富瓦烯与等物质的量的氢氧化铯作用,生成去保护的3,6,7-三取代四硫富瓦烯-2-硫负离子,后者与三(碘乙基)胺或1,3,5-三(溴甲基)苯反应生成带有3个四硫富瓦烯取代的三脚型电子给体化合物。用NMR、MS和元素分析等手段证实了产物的结构,并用CVs研究了它们的电化学性质。对循环伏安图进行电流微分结果证明,标题化合物的电极反应为分步过程。     

四硫富瓦烯类衍生物的合成及表征

以金属钠和二硫化碳为起始原料,合成四硫富瓦烯(TTF)锌的配合物(TTF)Zn(NBu_4)_2。其与卤代烷烃或取代类酰氯反应得到16个对称的四硫富瓦烯硫酮类衍生物,再经醋酸汞氧化分别得到16个四硫富瓦烯氧酮类衍生物,其中13个未见文献报道。操作简单且收率达80%以上,其结构经~1H NMR、~(13)C NMR表征确证。     

合成四烃硫基四硫富乙烯的研究进展

描述了四烃硫基四硫富瓦烯的４种合成方法及其研究进展。     

合成四烃硫基四硫富瓦烯的研究进展

描述了四烃硫基四硫富瓦烯的4种合成方法及其研究进展.     

四硫富瓦烯基四硫纶及其配合物的合成

以二硫化碳、N，N-二甲基甲酰胺（DMF）为起始原料，亚磷酸三丁酯为偶联剂，合成了2，3，6，7-四（2’-氰乙硫基）网硫富瓦烯四硫纶（TTFTT），并以TTFTT为桥配体、邻菲啰啉为封端配体，制得了中心金属离子为Zn^2＋、Ni^2＋的四硫富瓦烯基四硫纶双金属配合物。中间物及产物经IR和元素分析进行了结构表征，其中目标产物元素分析的实测值与计算值比较吻合，说明合成路线合理可行。     

Sapindaceae,cyanolipids, and bugs

Scentless plant bugs (Heteroptera: Rhopalidae) are so named because adults of the Serinethinae have vestigial metathoracic scent glands. Serinethines are seed predators of Sapindales, especially Sapindaceae that produce toxic cyanolipids. In two serinethine species whose ranges extend into the southern United States,Jadera haematoloma andJ. sanguinolenta, sequestration of host cyanolipids as glucosides renders these gregarious, aposematic insects unpalatable to a variety of predators. The blood glucoside profile and cyanogenesis ofJadera varies depending on the cyanolipid chemistry of hosts, and adults and larvae fed golden rain tree seeds (Koelreuteria paniculata) excrete the volatile lactone, 4-methyl-2(5H)-furanone, to which they are attracted.Jadera fed balloon vine seeds (Cardiospermum spp.) do not excrete the attractive lactone. Loss of the usual heteropteran defensive glands in serinethines may have coevolved with host specificity on toxic plants, and the orientation ofJadera to a volatile excretory product could be an adaptive response to save time.Mention of a commercial product does not consititute an endorsement by the USDA.     

Insect antifeedant properties of anthranoids from the genusVismia

Vismiones and ferruginins, representatives of a new class of lypophilic anthranoids from the genusVismia were found to inhibit feeding in larvae of species ofSpodoptera, Heliothis, and inLocusta migratoria.     

Direct observation of freeze-thaw instability of latex coatings via high pressure freezing and cryogenic SEM

Despite its industrial importance, the subject of freeze-thaw (F/T) stability of latex coatings has not been studied extensively. There is also a lack of fundamental understanding about the process and the mechanisms through which a coating becomes destabilized. High pressure (2100 bar) freezing fixes the state of water-suspended particles of polymer binder and inorganic pigments without the growth of ice crystals during freezing that produce artifacts in direct imaging scanning electron microscopy (SEM) of fracture surfaces of frozen coatings. We show that by incorporating copolymerizable functional monomers, it is possible to achieve F/T stability in polymer latexes and in low-VOC paints, as judged by the microstructures revealed by the cryogenic SEM technique. Particle coalescence as well as pigment segregation in F/T unstable systems are visualized. In order to achieve F/T stability in paints, latex particles must not flocculate and should provide protection to inorganic pigment and extender particles. Because of the unique capabilities of the cryogenic SEM, we are able to separate the effects of freezing and thawing, and study the influence of the rate of freezing and thawing on F/T stability. Destabilization can be caused by either freezing or thawing. A slow freezing process is more detrimental to F/T stability than a fast freezing process; the latter actually preserves suspension stability during freezing. Presented at the 82nd Annual Meeting of the Federation of Societies for Coatings Technology, October 27–29, 2004 in Chicago, IL. Tied for first place in The John A. Gordon Best Paper Competition.     

2008～2009年世界塑料工业进展

收集了2008年7月～2009年6月世界塑料工业的相关资料,介绍了2008～2009年国外塑料工业的发展情况,提供了世界塑料产量、消费量及全球各类树脂的需求量及产能情况。按通用热塑性树脂(聚乙烯、聚丙烯、聚苯乙烯、聚氯乙烯、ABS树脂)、工程塑料(尼龙、聚碳酸酯、聚甲醛、热塑性聚酯、聚苯醚)、特种工程塑料(聚苯硫醚、液晶聚合物、聚醚醚酮)、通用热固性树脂(酚醛、聚氨酯、环氧树脂、不饱和聚酯树脂)不同品种的顺序,对树脂的产量、消费量、供需状况及合成工艺、产品应用开发、树脂品种的延伸及应用的进一步扩展等技术作了详细介绍。     

Ethanol and (−)-α-Pinene: Attractant Kairomones for Bark and Ambrosia Beetles in the Southeastern US

In 2002–2004, we examined the flight responses of 49 species of native and exotic bark and ambrosia beetles (Coleoptera: Scolytidae and Platypodidae) to traps baited with ethanol and/or (−)-α-pinene in the southeastern US. Eight field trials were conducted in mature pine stands in Alabama, Florida, Georgia, North Carolina, and South Carolina. Funnel traps baited with ethanol lures (release rate, about 0.6 g/day at 25–28°C) were attractive to ten species of ambrosia beetles (Ambrosiodmus tachygraphus, Anisandrus sayi, Dryoxylon onoharaensum, Monarthrum mali, Xyleborinus saxesenii, Xyleborus affinis, Xyleborus ferrugineus, Xylosandrus compactus, Xylosandrus crassiusculus, and Xylosandrus germanus) and two species of bark beetles (Cryptocarenus heveae and Hypothenemus sp.). Traps baited with (−)-α-pinene lures (release rate, 2–6 g/day at 25–28°C) were attractive to five bark beetle species (Dendroctonus terebrans, Hylastes porculus, Hylastes salebrosus, Hylastes tenuis, and Ips grandicollis) and one platypodid ambrosia beetle species (Myoplatypus flavicornis). Ethanol enhanced responses of some species (Xyleborus pubescens, H. porculus, H. salebrosus, H. tenuis, and Pityophthorus cariniceps) to traps baited with (−)-α-pinene in some locations. (−)-α-Pinene interrupted the response of some ambrosia beetle species to traps baited with ethanol, but only the response of D. onoharaensum was interrupted consistently at most locations. Of 23 species of ambrosia beetles captured in our field trials, nine were exotic and accounted for 70–97% of total catches of ambrosia beetles. Our results provide support for the continued use of separate traps baited with ethanol alone and ethanol with (−)-α-pinene to detect and monitor common bark and ambrosia beetles from the southeastern region of the US.     

Many Drugs of Abuse May Be Acutely Transformed to Dopamine,Norepinephrine and Epinephrine In Vivo

It is well established that a wide range of drugs of abuse acutely boost the signaling of the sympathetic nervous system and the hypothalamic–pituitary–adrenal (HPA) axis, where norepinephrine and epinephrine are major output molecules. This stimulatory effect is accompanied by such symptoms as elevated heart rate and blood pressure, more rapid breathing, increased body temperature and sweating, and pupillary dilation, as well as the intoxicating or euphoric subjective properties of the drug. While many drugs of abuse are thought to achieve their intoxicating effects by modulating the monoaminergic neurotransmitter systems (i.e., serotonin, norepinephrine, dopamine) by binding to these receptors or otherwise affecting their synaptic signaling, this paper puts forth the hypothesis that many of these drugs are actually acutely converted to catecholamines (dopamine, norepinephrine, epinephrine) in vivo, in addition to transformation to their known metabolites. In this manner, a range of stimulants, opioids, and psychedelics (as well as alcohol) may partially achieve their intoxicating properties, as well as side effects, due to this putative transformation to catecholamines. If this hypothesis is correct, it would alter our understanding of the basic biosynthetic pathways for generating these important signaling molecules, while also modifying our view of the neural substrates underlying substance abuse and dependence, including psychological stress-induced relapse. Importantly, there is a direct way to test the overarching hypothesis: administer (either centrally or peripherally) stable isotope versions of these drugs to model organisms such as rodents (or even to humans) and then use liquid chromatography-mass spectrometry to determine if the labeled drug is converted to labeled catecholamines in brain, blood plasma, or urine samples.