硫化物改性氯铝酸盐离子液体催化甲苯选择性氯化反应的研究

分别将硫、二甲硫醚和乙二硫醇3种含硫物添加到制备的咪唑基氯铝酸盐离子液体[BMIM]Cln Al Cl3(n=1、1.5、2和2.5)中,制备了含硫物改性的咪唑基氯铝酸盐离子液体。合成的催化剂在甲苯选择性氯化反应中有较高的催化活性和对氯甲苯选择性。当以乙二硫醇改性的[BMIM]Cl-2Al Cl3离子液体为催化剂,催化剂用量为甲苯质量的3%,在70℃下反应8 h时,甲苯完全转化,对氯甲苯的选择性为70.4%;该催化剂易于与氯化产物分离,具有良好的稳定性和循环性能。     

酸性离子液体催化合成N,N’-亚甲基双丙烯酰胺

以N-甲基咪唑、2-氯乙基苯、硫酸氢钾合成1-甲基-3-[α-甲基-(4-磺酸苄基)]咪唑硫酸氢盐酸性离子液体,考察了酸性离子液体在甲醛和丙烯腈反应合成N,N’-亚甲基双丙烯酰胺(MBA)中的催化性能。结果表明,合成MBA的最佳反应条件为∶n(甲醛)∶n(丙烯腈)=1.2∶1.0,酸性离子液体用量为丙烯腈质量的8.0%,反应温度70℃,反应时间2 h。在该条件下MBA的收率>92%,纯度为98%以上,且反应结束后,产物易于分离,酸性离子液体可循环使用5次以上。     

乙氧亚甲基丙二酸二乙酯合成工艺的研究

乙氧亚甲基丙二酸二乙酯 (EMME)作为一类很重要的合成中间体 ,由丙二酸二乙酯(MDE)与原甲酸三乙酯 (OFE)在催化剂存在及少量乙酸或乙酸酐做缩合介质合成的。主要讨论了不同催化剂、原料配比、转化时间等因素对收率的影响 ,获得合成 EMME较佳工艺条件 :用活性白土作为载体 ,负载 5% Zn作为催化剂 ,催化剂用量为加入原料 MDE的 0 .3% (质量分数 ) ,OFE/MDE=3.2∶ 1 (摩尔比 ) ,乙酸酐 :MDE=0 .1∶ 1 (摩尔比 ) ,转化时间 8.0 h。 EMME的收率可达到98% (以丙二酸二乙酯计 )     

咪唑型室温离子液体介质中甲苯氯甲基化反应的研究

在溴化N,N-二烷基咪唑型室温离子液体反应介质中,尝试了甲苯、多聚甲醛和氯化氢气体的氯甲基化反应。以[C5mim]Br为催化剂,考察了反应温度、反应时间和离子液体用量对反应转化率的影响,获得的较佳反应条件为:反应温度65℃,反应时间10h,离子液体催化剂用量为甲苯物质的量的4%,在此条件下甲苯的转化率为82.6%,单氯甲基化选择性为100%。随着溴化N,N-二烷基咪唑型室温离子液体烷基链的增长,甲苯转化率有所提高;以溴化N-十二烷基-3-甲基咪唑离子液体为催化剂时,甲苯转化率可达90%,单氯甲基化选择性为100%。反应结束后产物与离子液体自动分层,便于分离。离子液体催化剂重复使用6次,甲苯转化率保持恒定。     

Amberlyst 70磺酸树脂催化合成丙二酸二乙酯

以Amberlyst 70磺酸树脂为催化剂催化丙二酸与乙醇的酯化反应,合成重要的精细化工中间体丙二酸二乙酯。考察反应时间、反应温度、醇酸物质的量比、催化剂用量等对酯化反应的影响,优化反应条件。结果表明,在醇酸物质的量比为3∶1、催化剂用量为丙二酸质量的10%、反应时间2 h和反应温度120℃的条件下,丙二酸二乙酯产率和选择性98.9%。表明Amberlyst 70磺酸树脂对丙二酸与乙醇的酯化反应有较高的催化活性。     

1-乙基-3-甲基咪唑硫酸乙酯离子液体的合成工艺

以N-甲基咪唑和硫酸二乙酯为原料,采用一步法合成1-乙基-3-甲基咪唑硫酸乙酯离子液体(EMIES)。研究了反应温度、投料比以及溶剂对产率的影响,并用高效液相色谱法(HPLC)检查了产品的纯度,优化了EMIES的合成工艺。实验结果表明:在温度50℃,无溶剂,N-甲基咪唑和硫酸二乙酯投料比为1∶1.2,反应2h的反应条件下,收率可达97%,且产品纯度可达99%。     

离子液体催化合成嘧啶氨基酸酯类化合物

以离子液体1-丁基-3-甲基咪唑氯盐([BMIM]Cl)为催化剂，合成了嘧啶氨基酸酯类化合物。研究了不同的常规溶剂和离子液体溶剂对嘧啶氨基酸酯类化合物产率的影响，以离子液体1-丁基-3-甲基咪唑溴盐([BMIM]Cl)为催化剂，在温度为90℃的最优反应条件下一锅法合成了8个嘧啶氨基酸酯衍生物(4a～4h),具有较高的产率(82%～93%)。通过离子液体回收利用实验结果表明，重复使用5次后活性无明显下降，此外，生物活性测试结果表明，该类衍生物对猕猴桃溃疡病菌、柑橘溃疡病菌、水稻白叶枯病菌具有一定的活性，其中，2-(((5-氯-4-甲氧基-6-甲基嘧啶-2-基)氨基)(4-氯苯基)甲基)丙二酸二乙酯对猕猴桃溃疡病菌、柑橘溃疡病菌、水稻白叶枯病菌活性分别为71.5%、63.0%、55.4%,优于对照药剂叶枯唑对3种病菌的抑制活性。     

超声波辅助合成氯化1-甲基-3-苄基咪唑离子液体及其对木材的溶解

以超声波辅助法合成了氯化1-甲基-3-苄基咪唑离子液体([Bzmim]Cl),并对其结构进行了紫外光谱(UV)和傅里叶红外光谱(FT-IR)表征。考察了反应条件对Cl收率的影响,实验结果表明超声波强化了离子液体的合成过程,能明显缩短合成时间。Cl较优的合成条件为超声波功率100 W、反应温度80℃、反应时间1 h、氯苄与1-甲基咪唑物质的量之比值1.1,此时离子液体的收率约为99.8%,纯度为98%。探讨了不同温度下离子液体[Bzmim]Cl对杉木木屑的溶解性能,结果表明活化后的杉木木屑在120℃时溶解度约为5.4。     

氯化1-乙基-3-丁基咪唑离子液体的合成

以N-乙基咪唑和氯代正丁烷为原料在一定条件下合成了氯化1-乙基-3-丁基咪唑离子液体([BEIM]Cl),通过考察温度等因素对[BEIM]Cl的影响得出合成离子液体的最佳工艺条件为:N-乙基咪唑∶氯代正丁烷为1∶1.2(摩尔比),溶剂二甲苯为0.9 mL/g(每克N-乙基咪唑0.9 mL溶剂),在其共沸温度下反应18 h。该合成方法操作简单,反应条件温和,在最佳工艺条件下产物收率可达95%。     

Br(o)nsted酸性离子液体中苯甲酸酯、苄酯的无溶剂微波合成

该文以1-甲基咪唑、吡啶、苄基氯、硫酸、磷酸为原料,合成了4种Brnsted 酸性离子液体:1-甲基-3-苄基咪唑硫酸氢根盐(a),1-甲基-3-苄基咪唑磷酸二氢根盐(b),N-苄基吡啶硫酸氢根盐(c),N-苄基吡啶磷酸二氢根盐(d),以它们作为催化剂和反应介质,考察了苯甲酸与系列脂肪醇、苄醇与系列脂肪酸、苯甲酸在无溶剂和微波辐射反应条件下的Fischer酯化反应,结果表明,当苯甲酸或苄醇与离子液体的摩尔比为1∶ 0.5时,无需外加催化剂,反应即可在化学计量条件下进行,12～20 min完成反应,苯甲酸酯与苄酯的收率分别为77%～98%和78%～98.5%,气相色谱纯度≥95%.离子液体循环使用3次,催化活性仅下降1.8%～3.4%.     

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.     

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.     

ICP-MS法测定地球化学样品中As、Cr、Ge、V等18种微量痕量元素的研究

建立了测定地球化学样品中包括As、Cr、Ge、V等18种微量、痕量元素的ICP-MS方法。地化试样用HF-HNO3混酸分解后,以1 1 HNO3溶解干渣。由于制样不使用盐酸,避免了Cl对As、Cr、Ge、V的质谱干扰。用国家一级地球化学标准物质GBW 07309制备溶液优化仪器工作参数,并用于校准。方法测定限(6s)为:0.007~6.4μg/g,精密度(RSD%,n=12)为:29%~9.4%,经过国家一级地球化学标准物质的分析验证,结果与标准值吻合。方法已应用于国土资源调查的试样分析。     

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.     

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.     

基于ATRP法制备的触角状亲水性羟胺树脂的吸硼性能的研究

以大分子引发剂氯乙酰化聚苯乙烯微球(PS-acyl-Cl)经原子转移自由基聚合(ATRP)法引发丙烯酰胺(AM)和甲基丙烯酸缩水甘油酯(GMA)单体的共聚接枝,制得一种触角状亲水性环氧载体(PS-acyl-g-P(AM-co-GMA)),再经二乙醇胺(DEA)的环氧基开环胺化反应,得到一种含多个-NCH2CH2OH螯合配基的多齿-五元螯合环的触角状亲水性羟胺树脂(PS-acyl-g-P(AM-co-GMA)-DEA)。将此树脂用于硼吸附研究,结果表明,PS-acyl-g-P(AM-co-GMA)-DEA树脂对硼的吸附满足Langmuir方程,为单分子层吸附;饱和吸附量约为37.7 mg·g-1,且树脂5 min即可达到吸附平衡,与其它已报道的吸硼树脂相比,该树脂具有更高的吸附量和吸硼速率。吸附动力学研究表明,树脂吸附硼的过程主要由颗粒扩散过程控制。重复使用5次后该树脂的吸附量基本不变,解吸率均在90%以上,重复使用性能良好。