Functionalized carbon dots as sensors for gold nanoparticles in spiked samples: Formation of nanohybrids

This paper reports the synthesis, passivation and functionalization of luminescent carbon dots (CDs) possessing surface thiol ending groups. A simple procedure involving amidation of passivated carbon dots (p-CDs) with cysteamine boosts their photoluminescent properties and enables their use as easily controlled fluorescent nanosensors for determining citrate–gold nanoparticles (AuNPs). The mechanism behind the quenching phenomenon was established from fluorescence measurements at high temperatures and lifetime tests, and found to involve static quenching leading to the formation of CD–AuNP nanohybrids. A method for determining AuNPs in complex matrices was developed and validated by application to spiked drinking water and mussel tissues. The limits of detection and quantitation for AuNPs thus obtained were 0.20 and 0.66 nmol L^–1, respectively.     

纳米线组装叶片状三氧化钼的合成及其对三乙胺的气敏性能

通过溶剂热法制备了由一维纳米线自组装的叶状三氧化钼纳米材料，借助X射线衍射（XRD）、场发射扫描电子显微镜（FESEM）、透射电子显微镜（TEM）、高分辨透射电镜（HRTEM）、紫外-可见漫反射光谱（UV-Vis DRS）、热重-示差扫描量热（TG-DSC）、氮气吸附（N₂-sorption）等技术对材料进行了系统的组成和结构表征。结果表明，一维纳米线表面具有粗糙结构，且由一维纳米线组装的叶片状三氧化钼属畸变八面体中的正交晶系，其主要暴露的结晶面是（021）。此叶片状三氧化钼气敏材料在300℃的最佳工作温度下，对2.25 g·m^-3的三乙胺表现出优异的选择性、超高的灵敏度和较快的响应时间（5 s），甚至在浓度为4.5 mg·m^-3的检测标准下响应值仍可达到12.4。基于以上结构表征和性能测试结果，对叶片状三氧化钼的形成及三乙胺敏感机理进行了初步探讨分析。     

离子液体[Et_3NH]Cl-0.5FeCl_3汽油深度脱硫的研究

以成本较低的盐酸三乙胺和三氯化铁为原料合成离子液体[Et3NH]Cl-0.5FeCl3,用于模拟汽油(二苯并噻吩溶于正辛烷配制而成)萃取脱硫。通过单因素实验考查了剂油比、萃取温度和萃取时间对模拟汽油脱硫率的影响。并考察其对真实FCC汽油的脱硫效果。研究结果表明,当萃取温度T=50℃,剂油比v(IL):v(oil)=0.2∶1,萃取时间t=50min时,模拟汽油脱硫率可达96.19%。经过4步萃取,使真实FCC汽油硫含量低于10ppm,符合国V标准对硫含量的要求。离子液体循环使用5次后脱硫率没有明显下降。     

反相液相色谱中离子抑制剂的有机调节剂作用

系统地研究了在反相液相色谱（RPLC）流动相中作为离子抑制剂的酸、碱及缓冲溶液对中性化合物保留行为的影响,着重探讨了有机酸、有机碱离子抑制剂的有机调节剂作用,定量地考察了甲醇和乙腈、甲醇和乙酸、甲醇和三乙胺、乙腈和乙酸、乙腈和三乙胺在十八烷基硅烷键合相上洗脱强度之间的关系,为RPLC中有机调节剂的洗脱强度排序提供一种评判方法．另外,讨论了乙酸和三乙胺作为有机调节剂时不同的作用机理．本实验结果对于RPLC分离方法的快速建立和准确优化都具有一定的借鉴意义．     

266nm激光下三乙胺分子多光子电离质谱研究

利用YAG激光器输出的四倍频激光对三乙胺分子的共振增强双光子电离过程进行了研究,获得了三乙胺分子的飞行时间质谱,母体离子及碎片离子信号达29种之多.对碎片离子（C₂H₅）₂N⁺CH₄（86⁺）异常漂移做了分析,发现了异常漂移是由于离子信号强度过强时,86⁺之前的25种离子对其25次瞬间减速效应强于之后的3种离子对其3次瞬间加速效应造成的.     

Review of recent advances in the preparation of organic polymer monoliths for liquid chromatography of large molecules

In recent years the use of monolithic polymers in separation science has greatly increased due to the advantages these materials present over particle-based stationary phases, such as their relative ease of preparation and good permeability. For these reasons, these materials present high potential as stationary phases for the separation and purification of large molecules such as proteins, peptides, nucleic acids and cells. An example of this is the wide range of commercial available polymer-based monolithic columns now present in the market.     

紫外分光光度法测定热敏纸中的双酚S

为了检测热敏纸中的双酚S(BPS),提出了一种基于三乙胺(TEA)碱解BPS,并用紫外分光光度法进行检测的方法.研究了三乙胺的体积分数、反应时间、反应温度对体系吸光度(A)的影响,优化了样品提取条件:提取溶剂、提取时间、提取温度、料液比.结果表明,经碱解后双酚S体系的最大吸收波长由257 nm红移至294 nm,相应的A增大,测定BPS的线性为5.00×10^-5~3.00×10^-2 g/L,线性相关系数为0.995 1,检测限为5.00×10^-5 g/L.这种方法简单快捷,结果稳定准确,适用于热敏纸中BPS的测定.     

The activation of tertiary amines by osmium cluster complexes: Further studies of the reaction of Os3(CO)10(NCMe)2 with triethylamine

The reactions of Os₃(CO)₁₂ and Os₃(CO)₁₀(NCMe)₂ with NEt₃ have been reinvestigated. Two new products, Os₃(CO)₁₀(μ-CH₂C(H)?NEt₂)(μ-H)) (2) and Os₃(CO)₁₀(syn-μ-η¹-CHCHNEt₂)(μ-H) (3) were obtained in low yields, 4% and 7%, in addition to the previously reported compound Os₃(CO)₁₀(anti-μ-η¹-CHCHNEt₂(μ-H) (1) (20% yield) when the reaction was conducted at 25°C using Os₃(CO)₁₀(NCMe)₂. Compounds 2 and 3 were characterized by IR, ¹H NMR and single-crystal X-ray diffraction analyses. Compound 2 contains a bridging methyl-metallated N-ethylimine ligand formed by the cleavage of one ethyl group from the NEt₃. Compound 3 is an isomer of 1 in which the bridging ligand has a syn conformation with respect to the cluster as compared with the anti conformation in 1. Compound 3 slowly isomerizes to 1. Compound 3 is de-carbonylated by exposure to UV radiation and is transformed to the new compound Os₃(CO)₉(μ₃-CC(H)?NEt₂)(μ-H)₂ (4) (58% yield) by an additional CH activation to form a triply bridging η¹-diethylaminovinylidene ligand. Compound 4 isomerizes to the compound Os₃(CO)₉(μ₃-HCCNEt₂)(μ-H)₂ (5) (70% yield) at 68°C. The latter contains a triply briding ynamine ligand which exhibits structural and reactivity features that are characteristic of a carbene ligand at the amine-substituted carbon atom. Crystal data: for 2, space group = P2₁/c, a = 9.236(2) Å, b = 12.469(2) Å, c = 18.107(3) Å, β = 104.67(1)°, Z = 4, 2518 reflections, R = 0.031; for 3, space group = P2₁/m, a = 7.644(1) Å, b = 12.706(2) Å, c = 11.912(2) Å, β = 108.02(1)°, Z = 2, 1295 reflections, R = 0.030; for 4, space group = P2₁/n, a = 10.233(2) Å, b = 14.834(4) Å, c = 14.538(2) Å, β = 99.88(2)°, Z = 4, 2403 reflections, R = 0.036.     

Stereoselective synthesis of functionalized vinyl ethers from allyl bromides activated by triethylamine

An efficient coupling reaction of allyl bromides with various alcohols as nucleophiles activated by triethylamine, leading to functionalized vinyl ethers in good yields and with full stereoselectivity.