邻苯二酚的高效液相色谱分析

本文提出了邻苯二酚成品质量的高效液相色谱分析方法。     

N-(取代)对三氟甲基苯基-1,3,5-三取代吡唑-4-酰胺衍生物的合成与生物活性

设计合成10个未见文献报道的N-对三氟甲基苯基-1,3,5-三取代吡唑-4-酰胺类化合物, 其结构经元素分析, ¹H NMR, IR 确证. 初步生物活性测试结果表明, 部分化合物对水稻纹枯病、小麦赤霉病、辣椒枯萎病和马铃薯晚疫病有一定的杀菌活性.     

Catalytic asymmetric dipolar cycloadditions of indolyl delocalized metal-allyl species for the enantioselective synthesis of cyclopenta[b]indoles and pyrrolo[1,2-a]indoles

The development of novel synthons and efficient methods to synthesize chiral polycyclic indoles has been a hot topic in organic synthesis and medicinal chemistry owing to their broad applications in medicines, pesticides, and other functional molecules.Here, we disclosed novel indolyl substituted metal-allyl zwitterionic intermediates through the decarboxylation of conveniently available vinyl indoloxazolidones, which could be regarded as two types of dipolar species through the anionic delocalization.The palladium-π-allyl species tended to serve as an all-carbon 1,3-dipole in the asymmetric [3+2] cycloaddition with electrondeficient alkenes, which furnished polysubstituted cyclopenta[b]indoles with high regio-and stereoselectivities. Meanwhile, the iridium-π-allyl species was recognized as an aza-1,3-dipole in asymmetric [3+2] cycloaddition with in situ generated C1 ammonium enolates, affording pyrrolo[1,2-a]indoles with high diastereo-and enantioselectivities. In addition, the dipolar cycloadditions could be easily scaled-up and several synthetic transformations of the cycloadducts were demonstrated for the rapid synthesis of diverse chiral polycyclic indoles.     

甲苯磺丁脲稀土络合物的制备及其性质研究

本文报导了15种甲苯磺丁脲稀土络合物的制备方法。用元素分析确定了它们的组成,测定了它们的物理化学性质,对它们的红外光谱、紫外光谱、核磁共振谱、X-射线粉末图进行了研究,并讨论了它们的热稳定性。     

Fast field analysis of short-chain aliphatic amines in water using solid-phase microextraction and a portable gas chromatograph

A novel method is firstly presented for field and rapid analysis of short-chain aliphatic amines in water as their pentafluorobenzaldehyde (PFBAY) derivative using solid-phase microextraction (SPME) and portable GC. In the proposed method, short-chain aliphatic amines in water rapidly reacted with PFBAY, and then were headspace extracted and concentrated by SPME. The formed amines derivatives were analyzed by portable GC. The SPME parameters of fiber selection, extraction temperature, extraction time, and stirring rate were studied. The method validations including LOD, recovery, precision, and linearity were studied. It was found that the proposed method required the whole analysis time 22 min, and provided low LOD of 1.2-4.6 ng/mL, good recovery of 91-106%, good precision of RSD value 3.5-9.3%, and linear range 20.0-500 ng/mL (r(2) >0.99). The obtained results demonstrated that the SPME-portable GC is a simple, rapid, and efficient method for the field analysis of short-chain aliphatic amines. Finally, the proposed method was further applied to the quantification of ethylamine, propylamine, and butylamine in environmental water.     

Ab initio studies on reaction H2C=C(OH)Li+CH3 + (CH3 -)

The possible structures and isomerizations of H₂C=C(OH)Li are studied theoretically by the gradient analytical method at RHF/6-31+G level. According to these results, reactions of H₂C=C(OH)Li with CH₃ ⁺ and CH ₃ ^- are investigated thoroughly. When H₂C=C(OH)Li reacts with CH ₃ ⁺ , H_zC=C(OH)Li firstly changes from structure1 to structure4, and then combines with CH₃ ⁺. In this reaction, the configuration of central carbon is retained. When H₂C=C(OH)Li reacts with CH ₃ ^- , structure1 firstly breaks its C-O bond to give contact ion-pair. Then through transition state16 which is similar to structure2, the attack of CH ₃ ^- from the opposite side of^-OH replaces^-OH group and inverts the configuration of carbenoid carbon atom. All the results show that the ambident reactivity of carbenoid has close relationship with the stability of special structures. Project supported by the National Natural Science Foundation of China (Grant No. 29773025).     

Modular peripheral functionalization of thiophene dendrons and dendrimers

A series of thiophene dendrons and dendrimers with peripheral functional groups were designed and synthesized. Two methodologies using thiophene dendrons and dendrons as synthetic building blocks, namely, (1) periphery functionalization; (2) a combination of focal and periphery functionalization have been demonstrated.     

Speciation of chromium by in-capillary reaction and capillary electrophoresis with chemiluminescence detection

A sensitive method for the simultaneous determination of chromium(III) (Cr3+) and chromium(VI) (CrO4(2-)) using in-capillary reaction, capillary electrophoresis (CE) separation and chemiluminescence (CL) detection was developed. The chemiluminescence reaction was based on luminol oxidation by hydrogen peroxide in basic aqueous solution catalyzed by Cr3+ ion followed by capillary electrophoresis separation. Based on in-capillary reduction, chromium(VI) can be reduced by acidic sodium hydrogensulfite to form chromium(III) while the sample is running through the capillary. Before the electrophoresis procedure, the sample (Cr3+ and CrO4(2-)), buffer and acidic sodium hydrogensulfite solution segments were injected in that order into the capillary, followed by application of an appropriate running voltage between both ends. As both chromium species have opposite charges, Cr3+ ions migrate to the cathode, while CrO4(2-) ions, moving in the opposite direction toward the anode, react with acidic sodium hydrogensulfite which results in the formation of Cr3+ ions. Because of the migration time difference of both Cr3+ ions, Cr(III) and Cr(VI) could be separated. The running buffer was composed of 0.02 mol l(-1) acetate buffer (pH 4.7) with 1 x 10(-3) mol l(-1) EDTA. Parameters affecting CE-CL separation and detection, such as reductant (sodium hydrogensulfite) concentration, mixing mode of the analytes with CL reagent, CL reaction reagent pH and concentration, were optimized. The limits of detection (LODs) of Cr(III) and Cr(VI) were 6 x 10(-13) and 8 x 10(-12) mol l(-1) (S/N=3), respectively. The mass LODs for Cr(III) and Cr(VI) were 1.2 x 10(-20) mol (12 zmol) and 3.8 x 10(-19) mol (380 zmol), respectively.     

丙氨酸稀土二元和三元配合物的pH电位法研究

本文报道在生理条件下(37℃,I=150 mmol/L NaCl)用pH电位法研究Ala-Ln、GIu—Ln及Ala-Glu-Ln中(Ala=L-丙氨酸,Glu=L-谷氨酸,Ln=Ce,Pr,Nd,Y)二元及三元配合物的稳定常数,运用MINIQUAD-82A程序确定粒子组成,并由COMPLEX程序获得配位粒子分布图,结果表明,三价稀土离子形成配合物的稳定顺序为:Ce相似文献