Improvement of pore geometry and performances of poly(ethylene terephthalate) track membranes by a protective layer method using plasma-induced graft polymerization of 1H,1H,2H-perfluoro-1-octene monomer

The process of geometrical modification of pores in poly(ethylene terephthalate) track-etched membranes (TM) by use of plasma deposition of a fluorine-containing polymer protective layer on one membrane surface and alkali etching of the other surface has been studied in order to produce membranes with improved performance characteristics. Samples of membranes with conical pores have been obtained which have better filtration efficiency compared with initial TM with cylindric pores. Plasma polymerization of 1H,1H,2H-perfluoro-1-octene at the membrane surface was used to produce the protective layer resistant to alkali solutions. The occurrence of plasma modification and changing of pore geometry have been verified by X-ray photoelectron spectroscopy and scanning electron microscopy studies. The filtration efficiency and selectivity of the modified membranes have been studied.     

Eremophilane esters of Robinsonecio gerberifolius and their rearranged products. Study of the coupling constants (2)J(H, H), (3)J(H, H) and (4)J(H, H)

In the course of the basic hydrolysis of four eremophilane esters isolated from Robinsonecio gerberifolius, some rearrangements, eliminations, and additions occurred. Five compounds were obtained, three of them not previously described. Additionally, a new sesquiterpene was produced by autooxidation of compound 1. The (1)H and (13)C NMR spectra of these compounds were completely assigned by utilization of HMQC, HMBC, COSY, DEPT, and NOESY techniques. The long-range coupling constants of the peroxide 10 are reported, and all its coupling constants (2)J(H, H), (3)J(H, H), and (4)J(H, H) are calculated at the B3LYP/6-31G(d,p) level of theory. Their magnitude is explained in terms of electronic delocalization and the additivity of stereoelectronic effects.     

1H and 13C spectral assignment of 2(1H)-pyridone derivatives

1H and 13C NMR spectroscopic data for 4-aryl-3,4-dihydro-6-methyl-2(1H)pyridone derivatives were fully assigned by a combination of one- and two- dimensional experiments (DEPT, HMBC, HMQC, COSY, NOE).     

Strong Axial Preference of 2-S Substituents in 3,4-Dihydro-2 H -1-Benzopyrans

The synthesis and crystal structure of a O,S,S-acetal derivative (1 R *,2 R *,2' S *)-1-(3,4-dihydro-2 H -1-benzopyran-2-ylthio)-2-phenyl-1-phenylthiopropan-2-ol 4 are reported. The 2-S-sidechain orientation in solution determined by OCHS signals in 1 H NMR spectra is mainly axial in all the 3,4-dihydro-2 H -1-benzopyran derivatives. Compound 4 crystallizes in the triclinic space group P 1 with an axial 2-S-sidechain and an intramolecular hydrogen bond between the OH and the ether oxygen with the O;;;O distance of 2.799(3) Å.     

H_2O_2氧化N_2生成N_2O和H_2O机理的研究

采用量子化学计算方法研究了Ｈ２Ｏ２ 氧化Ｎ２ 生成Ｎ２Ｏ 和Ｈ２Ｏ 的机理．结果发现, Ｈ２Ｏ２ 氧化Ｎ２ 先通过１ 个四元环过渡态形成中间体Ｈ２Ｎ２Ｏ２ 分子,Ｈ２Ｎ２Ｏ２ 再通过一个五元环过渡态形成Ｎ２Ｏ和Ｈ２Ｏ．根据计算得到的每步反应的活化能,得知Ｈ２Ｏ２ 氧化Ｎ２ 生成中间体Ｈ２Ｎ２Ｏ２ 分子是整个反应的控制步骤．     

Addition of Organolithium and Grignard Reagents to Pyrimidine-2(1H)-thione: Easy Access to 4-Substituted 3,4-Dihydropyrimidine-2(1H)-thiones

Organolithium and Grignard reagents are added to pyrimidine-2(1H)-thione, yielding 4-substituted 3,4-dihydropyrimidine-2-(1H)-thiones. Since the synthetic procedure can be performed on a multigram scale, and since pyrimidine-2(1H)-thione as well as the majority of organometallic reagents are readily available, the process described provides an easy access and complementary to other methods to 4-substituted 3,4-dihydropyrimidine-2-(1H)-thiones.     

TiO2对流感病毒(H1N1)灭活作用的研究

利用滴度测定和透射电镜观察研究了365 nm的紫外光照射下TiO2对流感病毒(H1N1)的灭活性能, 并结合催化剂样品的XRD分析、 N2气吸附性能测定及其在实验条件下的表面Zeta电势的测量结果, 探讨了催化剂用量、 焙烧温度、 比表面积以及表面电性与灭活性能的关系. 研究结果表明, 400 ℃时焙烧的TiO2对H1N1的灭活性最好; TiO2的表面电性对灭活性有显著影响; TiO2对H1N1的光催化灭活作用首先发生在H1N1的纤突部分, 纤突部分的破坏导致H1N1的失活, 分解直至矿化.      

1-烷基-4,6-二芳基四氢三嗪硫酮化合物的合成及其氧化反应

三芳基缩二胺与烷基硫脲在二氧六环回流条件下反应, 可生成1-烷基-4,6-二芳基四氢三嗪硫酮化合物3。利用芳香醛, 烷基硫脲和醋酸铵一锅法也能得到3, 而三芳基缩二胺与芳基硫脲反应, 则生成了咪唑啉的硫氰酸盐。室温下,在相转移催化剂TEBA存在时, 3可被高锰酸钾氧化, 得到1-烷基-4,6-二芳基-2(1H)三嗪酮化合物。     

氯化亚锡催化“一锅法”合成N1-取代的3,4-二氢嘧啶-2(1H)-酮

以芳香醛、乙酰乙酸乙酯(甲酯)、单取代脲为原料,氯化亚锡为催化剂,在无溶剂、80℃条件下,通过三组分"一锅法"合成了一系列N1-取代的3,4-二氢嘧啶-2(1H)-酮衍生物。考察了催化剂用量和反应温度对产品收率的影响。通过IR、~1H NMR、~(13)C NMR和元素分析对目标产物结构进行确证,提出了可能的催化作用机理。本文的合成方法具有催化剂活性高、廉价易得和反应时间短、条件温和、产率高、绿色环保等优点。     

亲电硫试剂参与的2-芳基-3-硫代-2,3-二氢喹啉-4(1H)-酮的合成研究

本文报道了以(E)-1-(2-对甲苯磺酰胺基)-3-芳基丙-2-烯-1-酮(1)为底物与N-硫代丁二酰亚胺(2)通过亲电环化反应合成2-芳基-3-硫代-2,3-二氢喹啉-4(1H)-酮类化合物。以三氟化硼乙醚为催化剂(20 mol %),1,2-二氯乙烷为溶剂,反应温度为60 _oC,可以60-92%的收率得到一系列2-芳基-3-硫代-4(1H)-喹啉酮衍生物,化合物3a-k均未见文献报道,其结构均经过₁H NMR, ₁₃C NMR以及高分辨质谱进行确定。     

Linear and nonlinear feature of electronic excitation energy in carbon chains HC2n+1H and HC2nH

Density functional theory has been used to investigate the geometries, bonding, and vibrational frequencies of HC_2nH (n = 1–13) and HC_2n+1H (n = 2–12). Vertical excitation energies for the X¹Σ → 1¹Σ transition of HC_2nH (n = 1–5) and for the X³Σ → 1³Σ transition of HC_2n+1H (n = 2–5) have been calculated by the time‐dependent density functional theory and ab initio second‐order multiconfiguration perturbation method, respectively. On the basis of the present calculations, explicit expressions for the size dependence of excitation energy in linear polyynes HC_2n+1H and HC_2n+1H are suggested. Such analytical λ ? n relationships show good agreement with experimental observations. Theoretical investigations of relevant excited states demonstrate that distinct linear and nonlinear spectroscopic features in such polyynes can be ascribed to similarity and difference in bonding between the ground and excited states in HC_2n+1H and HC_2nH. © 2004 Wiley Periodicals, Inc. Int J Quantum Chem, 2004     

光/电催化喹喔啉酮官能团化反应研究进展

喹喔啉酮作为重要的含氮杂环骨架,广泛应用于抗菌化合物、抗肿瘤药物、半导体材料中.因此,开发新方法合成不同官能团化喹喔啉酮以丰富其结构多样性在近年来广受关注.在众多合成方法中,喹喔啉酮的直接C–H官能团化是一类步骤经济性较高、简便高效地构建喹喔啉酮衍生物的重要方法.近年来,光催化、电催化和光电催化技术已发展成为现代有机合成中强有力的绿色合成工具,可以有效利用光能或者电能促进有机化学转化,减少传统有机反应中的高能耗.过去几年,化学工作者在光/电催化喹喔啉酮的直接C–H官能团化反应方面进行了大量研究,开发了系列不同官能团化喹喔啉酮的绿色合成方法.本文系统总结了喹喔啉酮的光/电催化官能团化研究最新进展,重点讨论了光/电催化下自由基历程的喹喔啉酮C–H键直接官能团化反应,反应类型主要包括喹喔啉酮的3-芳基化、3-烷基化、3-氟烷基化、3-烷氧基化、3-酰化、3-氨基化、3-膦酰化、3-巯基化、3-硅烷基化和环化反应等方面,这将有助于理解光/电催化喹喔啉酮官能团化反应.反应在温和条件下可以成功产生各种碳中心或杂原子为中心的自由基,这些自由基进一步与喹喔啉酮的3-位进行加成反应,进而开发出众多有效的方法来合成不同官能团化的喹喔啉酮.这些条件温和的反应方法已经有部分成功应用于合成具有重要生物活性的喹喔啉酮化合物.此外,药物中常见的一些重要官能团,例如三氟甲基和二氟甲基等可以顺利地引入到喹喔啉酮骨架结构,这些研究为喹喔啉酮衍生物的生物活性相关研究奠定了基础.本文还对当前光/电催化喹喔啉酮官能团化反应所面临的挑战和未来发展作了展望和总结,期待在不久的将来,有机合成工作者能基于喹喔啉酮的C–H键直接官能团化开发更多不同类型的新反应.另一方面,需要进一步开发新型的非均相可见光催化剂,实现光催化剂的回收与再利用,进一步降低反应成本,促进其在药物开发、功能材料合成等应用方面的发展.     

The structural and dynamic properties of 1‐bromodecane in urea inclusion compounds investigated by solid‐state 1H, 13C and 2H NMR spectroscopy

For asymmetric guest molecules in urea, the end‐groups of two adjacent guest molecules may arrange in three different ways: head–head, head–tail and tail–tail. Solid‐state ¹H and ¹³C NMR spectroscopy is used to study the structural properties of 1‐bromodecane in urea. It is found that the end groups of the guest molecules are randomly arranged. The dynamic characteristics of 1‐bromodecane in urea inclusion compounds are probed by variable‐temperature solid‐state ²H NMR spectroscopy (line shapes, spin–spin relaxation: T₂, spin‐lattice relaxation: T_1Z and T_1Q) between 120 K and room temperature. The comparison between the simulation and experimental data shows that the dynamic properties of the guest molecules can be described in a quantitative way using a non‐degenerate three‐site jump process in the low‐temperature phase and a degenerate three‐site jump in the high‐temperature phase, in combination with the small‐angle wobbling motion. The kinetic parameters can be derived from the simulation. Copyright © 2011 John Wiley & Sons, Ltd.     

Spectrophotometric determination of copper after adsorption of its 1-phenyl-4,4,6-trimethyl(1H, 4H)-pyrimidine-2-thiol complex onto microcrystalline naphthalene

A selective Spectrophotometric method has been developed for the trace determination of copper after adsorption of its 1-phenyl-4,4,6-trimethyl(1H, 4H)-pyrimidine-2-thiol (PTPT) complex onto microcrystalline naphthalene. The complex is quantitatively adsorbed on naphthalene in the pH range 7.5–11.5, separated by filtration, dissolved in dimethylformamide (DMF) and determined spectrophotometrically at 400 nm. Beer's law is obeyed in the concentration range 2.5–37.5 g of copper in 10 ml of DMF. The molar absorptivity and Sandell's sensitivity are 1.30 × 10⁴1 · mol^–1 · cm^–1 and 0.0048g cm^–2, respectively. Ten replicate analyses of a solution containing 20.0 g of copper gave a mean absorbance of 0.410 with a relative standard deviation of 0.91 %. The interferences of various ions have been studied and the method has been validated by the determination of copper in various standard reference materials, beers, wines, human hair, goat liver and environmental samples.On leave from St. Stephen's College, Delhi 110 007, India     

Rh2CO2/Al2O3上H2吸附及CO和H2共吸附

CO加氢反应机理一直是许多化学工作者感兴趣的课题．Rh催化剂因其优良的性能而被用于 CO加氢机理研     

Molecular structure of a zwitter-ionic 2-piperidinyl-4-dinitromethyl-1,3,5-triazin×(1H, 5H)-6-one salt

A zwitter-ionic salt 2-piperidinyl-4-dinitromethyl-1,3,5-triazin(1H,5H)-6-one is studied by the single crystal X-ray analysis. The crystals are monoclinic: a = 11.526(1) Å, b = 9.211(1) Å, c = 12.182(1) Å; β = 110.69(1)°, V = 1209.9(2) ų, space group P2₁/n; Z = 4, ρ_calc = 1.560 g/cm³. The transformation of the dinitromethyl fragment conformation, the conjugation of one of nitrogroups with the 1,3,5-triazine ring, and an intramolecular hydrogen bond are revealed. The 1,3,5-triazine cycle is strongly distorted due to lactam-lactim tautomerism.     

5-甲基-2(1H)吡啶酮的合成

以5-甲基-2-氨基吡啶为起始原料,通过重氮盐水解反应,合成了5-甲基-2(1H)吡啶酮,并对其合成工艺进行了研究,其结构经IR确证。     

A facile and environmental friendly strategy for the synthesis of N-methoxyquinolin-2(1H)-ones

A facile and environmental friendly protocol for the construction of N-methoxyquinolin-2(1H)-ones was developed using a stable and easily available N-methoxyquinoline-1-ium tetrafluoroborate as starting material. Due to the mild reaction conditions, a broad range of N-methoxyquinolin-2(1H)-ones with different functional groups have been prepared in reasonable yields.     

Propanal in the Syntheses of Alkyl-substituted 3-Cyano-2-piperidone, 3-Cyano-2,5,6,7-tetrahydropyrindin-2(1H)-one, and 3-Cyanopyridine-2(1H)-thione

Condensation of propanal with cyanothioacetamide and morpholine gave 3-cyano-4-ethyl-5-methyl-6-morpholino-2-piperidone, the structure of which was studied by X-ray analysis. Reaction of propanal with cyanothioacetamides and cycloalkanone enamines gave 3-cyano-4-ethyl-2,5,6,7-tetrahydropyrindin-2(1H)-one and 3-cyano-4-ethyl-5,6-hexamethylenepyridine-2(1H)-thione. The latter was used for the preparation of substituted 2-benzyloxycarbonylmethylthiopyridine and 3-amino-2-benzyloxycarbonylthieno[2,3-b]pyridine. __________ Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 7, pp. 1053–1059, July, 2005.     

2,4,6-三甲氧基苯-1-O-D葡萄糖苷的核磁共振谱的理论研究

The 1H and 13C-NMR of 2,4,6-trimethoxyphenol-1-O-D-glucopyranoside(Compound 1) isolated from Celastrus angulatus (Celastraceae) was calculated theoretically at the both levels HF/6-311+G(2d,p)//B3LYP/6-31G(d) and HF/6-311+G(2d,p)//B3LYP/6-31G(d,p) using the GIAO (gauge-independent atomic orbital) method. Statistical error analysis for theoretically predicted δH and δC values versus those experimentally observed for compound 1 was discussed. The results show that the theoretically predicted δH and δC values of β conformer of compound 1 are more close to the experimentally observed values than α conformer, and the β conformer of compound 1 is more stable than α conformer according to molecular energy theoretically calculated. So compound 1 is assigned to be 2,4,6-trimethoxyphenol-1-O-β-D-glucopyranoside, which is in good consistence with the conclusion deduced by the anomeric proton signal (δH=4.80, J=7.3 Hz) experimentally observed.