Bromine doped g-C3N4 with enhanced photocatalytic reduction in U(VI)

Research on Chemical Intermediates - In the process of uranium mining and smelting, large quantities of low-concentration uranium-containing wastewater have been produced. It is an ideal solution...     

Visible light induced tandem reactions: An efficient one pot strategy for constructing quinazolinones using in-situ formed aldehydes under photocatalyst-free and room-temperature conditions

A facile tandem route has been developed for constructing quinazolinones from various aminobenzamides and in-situ generated aldehydes. Visible light was found to play a dual role: first oxidizes the alcohol to the aldehyde and then facilitates its cyclization with o-substituted aniline. Furthermore, alcohols are perfect alternatives to aldehydes because they are greener, more available, more economical, more stable, and less toxic than aldehydes. The first reaction step continuously provides material for the second step, which effectively reduces loss through volatilization, oxidation, and polymerization of the aldehyde, while avoiding its toxicity. A variety of quinazolinones can be prepared in the presence of visible light without any additional photocatalyst. The developed synthesis protocol proceeds with the merits of mild conditions, broad substrate scope, operational simplicity, and high atom efficiency, with an eco-energy source under metal-free, photocatalyst-free, and ambient conditions.     

One-pot rapid synthesis of 4H-1-benzopyran derivatives in a deep eutectic solvent

A method for introducing a biologically active heterocycle, 2-methylquinoline into the 4-position of a 2-amino-4H-1-benzopyran skeleton is described. Choline chloride/glucose (1:1 molar ratio) was used as both the solvent and catalyst in the reaction of a salicylaldehyde, methylquinoline, and cyanoacetate to obtain 2-amino-4H-1-benzopyran derivatives in 48%–80% yields after short reaction times. The effects of the deep eutectic solvent type, substrate molar ratio, cosolvent, temperature, and reaction time were examined. The method has the advantages of simple steps, environmental friendliness, mild conditions, and wide substrate applicability. This is the first attempt to synthesize methylquinoline derivatives of 4H-1-benzopyran.     

深共融溶剂中合成2,4-二取代喹啉衍生物

在氯化胆碱和氯化锌组成的深共融溶剂中,以2-氨基苯乙酮和芳香炔烃为原料,通过环化偶联反应,合成了一系列2,4-二取代喹啉衍生物;当n(氯化胆碱)∶n(氯化锌)=1∶2,反应温度为80℃时,反应3 h即获得高达98%的产率.该方法无需额外添加催化剂,而且反应条件温和、操作简单、底物范围较广泛.     

Changes in the composition of volatile monoterpenes and sesquiterpenes of Pinus armandi, P. tabulaeformis, and P. bungeana in Northwest China

The volatile mono-and sesquiterpenes obtained from the needles and resin of Pinus armandi, P. tabulaeformis, and P. bungeana growing in the Qinling, Taibai, and Huanglong Mountain forest ecosystem were analyzed by means of GC-MS. Forty-eight constituents were identified, and α-pinene, β-pinene, 1R-α-pinene, β-caryophyllene, cadindiene, α-caryophyllene, D-limonene, and 1S-β-pinene were the major components of the mono-and sesquiterpenes in the needles and resin. The components of the volatile mono-and sesquiterpenes from the needles and resin at Qinling, Taibai, and Huanglong Mountains had remarkable differences in three pine species, whereas the monopertene content such as α-pinene, β-pinene, D-limonene, and camphene were mostly changed in the growing stage. The intraspecies variation in the different ecosystems can be attributed to the species’ geography and genetic variation, and even the adaptation of the pine species to different ecological environments. Moreover, monoterpenes and sesquiterpenes can be induced by the attack of bark beetles, of which the α-pinene, β-pinene, 1R-α-pinene, 1S-α-pinene, b-myrecene, and β-caryophyllene contents had positive relations with the attacking Dendroctonus armandi and D. valens. Published in Khimiya Prirodnykh Soedinenii, No. 5, pp. 430–433, September–October, 2006.     

邻苯二酚紫-示波计时电位法测定天然水中不同形态铝

报道邻苯二酚紫-示波计时电位法分别在酸性和碱性条件下直接检测天然水中的无机单核铝和总单核铝浓度。并用该法测定了水样中的总铝,有机单核铝和酸溶态铝,从而实现了天然水中5种Al形态的电化学测定。测定了20多个实际水样,与Driscoll方法进行了对照,结果基本一致。     

离子交换/8-羟基喹啉荧光法分别测定天然水中的无机和有机单核铝

采用离子交换／氯仿萃取－８－羟基喹啉荧光法（８－Ｏｘ－ＣＦ－ＥＦ）分别测定了天然水样中的无机和有机单核铝。与Ｄｒｉｓｃｏｌｌ建立的铝形态区分法进行了比较,结果一致,本法优点是：可以直接测定水中的无机单核铝,减少了实验误差。     

Solution-processable precursor route for fabricating ultrathin silica film for high performance and low voltage organic transistors

In this paper, we introduce a simple solution spin-coating method to fabricate silica thin film from precursor route in the condition of low temperature and atmospheric environment, which possesses a low leakage current, high capacitance, and low surface roughness. With silica film (~ 50 nm), high performance and low voltage (< 4 V) p-/n-type organic transistors are fabricated. This method shows great potential for industrialization owing to its characteristic of low consumption and energy saving, time-saving and easy to operate.     

Catalyst-free synthesis of quinazolinones by oxidative cyclization under visible light in the absence of additives

A general metal-free oxidative cyclization route was developed to synthesize quinazolinones under visible light. A series of substituted 2-aminobenzamides were reacted with aldehydes or ketones to produce the desired quinazolinones in good yields. Most importantly, the reaction did not require excess oxidant or high temperatures.     

氯仿萃取8-羟基喹啉荧光法测定天然水中的总单核铝和酸溶态铝

采用氯仿萃取８－羟基喹啉荧光光度法（８－ＨＱ－ＣＬ－ＭＦ）测定了天然水样中的总单核铝和酸溶态铝含量,与Ｄｒｉｓｃｏｌｌ的甲基异丁基酮萃取８－羟基喹啉－石墨炉原子吸收法（８－ＨＱ－ＭＩＢＫ－ＧＦ／ＡＡＳ）法进行了比较,结果一致。本法具有取样量小,检测快捷,灵敏度高,重现性好等突出优点,合适于天然水中的总单核铝和酸溶态铝的分析。研究了滤膜过渡,酸消化以及紫外酸消化对天然水中铝形态测定的影响。