O-烷基,O-芳基硫代磷酰取代硫脲和O-烷基硫代磷酰-双-取代硫脲的研究

通过O-烷基,O-芳基硫代磷酸异硫氰基酯和O-烷基硫代磷酸二异硫氰基酯与不同胺的加成,合成了通式为:的两系列有机磷化合物。这些化合物在文献中均未见报道。初步生物测试结果表明,它们都具有一定的除草活性,其中个别化合物有较高的除草活性。产物和中间体结构经红外光谱和核磁共振谱鉴定。并对合成中的一些问题进行了初步探讨。     

O-烷基O-取代苯基硫代磷酰胺酯类化合物的合成及其结构与杀虫活性的定量关系

合成了19种O-烷基O-取代苯基硫代磷酰胺酯类化合物,在定量测定其杀虫活性的基础上,对该类化合物进行了结构与活性定量关系的解析。结果表明,分子中芳基上取代基的电子效应与2,3-位上取代基的疏水性质对活性有重要影响。     

O-芳基-O-烷基-O-(1-甲硫基乙叉胺基)磷酸酯的合成及其生物活性研究

以盐酸羟胺、乙醛、取代酚类及烷氧基磷酰二氯为原料,合成了22个O-芳基-O-烷基-O-(1-甲硫基乙叉胺基)磷酸酯化合物,采用元素分析、红外光谱和1H NMR谱对其进行了表征.初步生物活性测定结果表明,部分化合物具有一定的杀菌、除草活性,许多化合物具有优良的杀虫活性.     

O-芳基苯基硫代膦酰肼及其旋光活性腙

某些膦酰肼及其衍生物只有生物活性。本文通过O-芳基苯基硫代膦酰氯与50％水合肼反应合成了O-芳基苯基硫代膦酰肼(Ⅰ),在有些反应中还分离到N,N′-双[O-芳基苯基硫代膦酰基]肼(Ⅱ)。Ⅰ与(-)-薄荷酮反应得旋光活性薄荷酮腙(Ⅲ),由于磷原子是手性的,产物为非对映异构体。     

O-芳基苯基硫代膦酰肼与某些羧基化合物的反应

为探索 O-芳基苯基硫代膦酰肼的反应性能、测试所得产物的生物活性,寻找活性结构,本文研究了它与几种羰基化合物α-(1,2,4 三唑基)片呐酮、邻苯二甲酰氯,反式菊酰氯和原甲酸三乙酯的反应,合成了21个新的     

S-烷基O-芳基硫代磷酸衍生物的合成及其杀虫活性的研究

研究了O,O-二烷基O-芳基硫代磷酸酯与三氧氧磷的异构化氯化反应。由此生成的S-烷基O-芳基硫代磷酰再与亲核试剂(醇,酚,硫醇,硫酚,伯胺或氨)在缚酸剂存在下反应,合成了42种化合物,其中34种未见文献报道。本文还研究了这类化合物的杀虫活性。     

O-乙基O-取代芳基N-异丙基硫代磷酰胺酯类化合物急性毒性与结构的相关性

通过测定O-乙基O-取代芳基N-异丙基硫代磷酰胺酯类化合物的急性毒性、疏水性、电性、水解性,对这类化合物的急性毒性与化学结构进行了定量构-效相关(QSAR)分析。表明该类药物的急性毒性与电偶极矩μ显著相关,提示药物分子与受体的作用可能含有偶极成分。根据实验所得的QSAR方程,证明该类药物分子当电偶极矩小(苯环对位有推电子基团)、亲水性高时,其急性毒性较低。     

三丁基锡O, O-二芳基二硫代磷酸酯的合成及生物活性的初步研究

本文报道了由三丁基氯化锡和0, 0-二芳基二硫代磷酸钾盐反应合成三丁基锡O,O-二硫代磷酸酯。并经IR, ^1H NMR, ^1^3CNMR, ^1^1^9SN NMR 和MS分析, 生物测定表明这类化合物具有较高的杀菌活性和除草性。     

手性芳基邻二醇的不对称合成

具有特定功能基团的手性芳基邻二醇是许多具有特殊功能的药物、农药和信息素的重要中间体,近年来手性芳基邻二醇类化合物的合成与应用研究引起了人们的广泛关注。本文从生物催化不对称合成和化学催化不对称合成两方面综述了近年来手性芳基邻二醇的合成进展,概述了前手性底物上取代基的电子效应和空间效应、手性催化剂的种类和反应体系等因素对合成手性芳基邻二醇产率及光学活性的影响,并对手性芳基邻二醇不对称合成的发展趋势进行了展望。     

N-(吡啶-2-基羰基)取代芳基磺酰胺的合成及除草活性

N-(吡啶-2-基羰基)取代芳基磺酰胺的合成及除草活性     

Friedel-Crafts Polymers. 6. Friedel-Crafts Polycondensation of p-Xylylerte Dibromide with Salicylic Acid and β-Resorcyiic Acid

Polymers were prepared by condensing p-xylylene dibromide separately with salicylic acid and β-resorcylic acid in the presence of anhydrous ferric chloride in dioxane. The polymer samples_were characterized by elemental analysis, by IR spectral study, by M determined by vapor pressure osmometry, by nonaqueous conducto-metric titration in pyridine, by TGA in air, and by viscosity measurements of polymer solutions in DMF. Polymeric metal chelates of Cu²⁺, Co²⁺, Zn²⁺, Ni²⁺, and Fe³⁺ with polymer samples were prepared and characterized by elemental analysis, by IR spectral study, and by TGA in air. The chelation ion-exchange properties of the polymer samples were studied by employing the batch equilibration method.     

Kinetics of thermoelectric signals under nanosecond laser heating of mercury in aqueous electrolyte solutions

Acetaldehyde oxidation to form acetic acid is enhanced by oxygen adsorbing ad-atoms to a great extent. At the same time, the oxidation is enhanced by the S_hole control by Bi, Te, Se and S ad-atoms, which do not adsorb oxygen. The number of unoccupied Pt sites isolated by these inactive ad-atoms (S_hole), which is available for reactions, is less than that required for the formation of poisoning species but equal to that required for the oxidation, resulting in the inhibition of the poison formation reaction and the enhancement of the oxidation. The same type of enhancement, that is, the enhancement both by the S_hole control by ad-atoms and by oxygen adsorbing ad-atoms, was previously found in the enhancement of formaldehyde oxidation by ad-atoms.     

Comparative determination of uranium in rock phosphates and columbite by ICP-OES,alpha &; gamma spectrometry

During this work selective separation of uranium from rock phosphate and columbite mineral was done before its quantitative estimation by using Inductively Coupled Plasma Optical Emission Spectrometery (ICP-OES). Uranium from the rock phosphate and columubite was extracted by sodium peroxide fusion followed by leaching in 2 M HNO₃. To avoid spectral interference in the estimation of uranium by ICP-OES, the selective separation of uranium from the leachate was carried out by using two different extractants, 30% Tributyl Phophates (TBP) in CCl₄ and a equi-volume mixture of Di(2-ethylhexyl) phosphoric acid (D2EHPA) & TBP in petrofin. Uranium was stripped from the organic phase by using 1 M ammonium carbonate solution. Determination of uranium by ICP-OES was done after dissolving the residue left after evaporation of ammonium carbonate solution in 4% HNO₃. The concentration of the uranium observed in the rock phosphates samples was 40–200 μg g⁻¹ whereas in columbite samples the concentration range was 100–600 μg g⁻¹. Uranium concentration evaluated by ICP-OES was complimented by gamma & alpha spectrometry. Concentration of uranium evaluated by gamma spectrometry in case of rock phosphate and coulmbite was in close agreement with the uranium content obtained by ICP-OES. Uranium determination by alpha spectrometry showed only minor deviation (1–2%) from the results obtained by ICP-OES in case of rock phosphates whereas in case of coulmbites results are off by 20–30%.     

Friedel-Crafts Polymers. 5. Friedel-Crafts Polycondensation of p-Xylylene Dichloride with Salicylaldehyde and o-Hydroxyacetophenone

Polymers were prepared by condensing p-xylylene dichloride (PXDC) separately with salicylaldehyde (SAL) and o-hydroxy-acetophenone (OHAC) in the presence of anhydrous ferric chloride in dioxane. The polymer samples were characterized by elemental analysis, measurement of their M by vapor pressure osmometry, by nonaqueous conductometric titration in pyridine, by IR spectral study, by TGA in air, and by viscometric study in DMF. The ion-exchange capacities of these polymeric ligands for selected metal ions were measured by the batch equilibration method and compared. Polymeric metal chelates of PXDC-SAL and PXDC-OHAC polymer samples with Cu^{2 +}, Ni²⁺, Co²⁺, Fe³ and Zn^{2 +} were prepared and characterized by elemental analyses, by IR spectral study, and by thermal analyses.     

Methyl-substituted trans-1,2-cyclohexanediamines as new ligands for oxaliplatin-type complexes

Three different pathways for the synthesis of substituted trans-(±)-1,2-cyclohexanediamines as new ligands for oxaliplatin-type compounds are presented. The different synthetic routes lead (i) by the synthesis of the compound via ortho-bromination of a substituted cyclohexanone followed by reaction with hydroxylamine and reduction by hydrogen, (ii) by addition of azide to cyclohexene mediated by manganese(III) acetate and reduction by hydrogen, or (iii) by trans-dihydroxylation of cyclohexene, and subsequent conversion into the respective mesylate or tosylate, followed by substitution by azide, and reduction in the case of 4-methyl-trans-(±)-1,2-cyclohexanediamine to a preferentially equatorially, mainly axially, or exclusively equatorially or axially oriented 4-methyl group, respectively.     

Synthesis and characterization of chitosan-based polyurethane elastomer dispersions

Abstract  

A number of aqueous polyurethane dispersions were synthesized by the reaction of poly(ε-caprolactone) and isophorone diisocyanate, extended with different mass ratios of chitosan and dimethylol propionic acid. Their chemical structures were characterized by using FTIR, ¹H NMR, and ¹³C NMR spectroscopy, and thermal properties were determined by TGA. Incorporation of chitosan into the polyurethane backbone improved thermal stability. The hydrophilicity of the prepared polymers was also examined by contact angle measurements. For all samples, the contact angles increased by increasing the amount of chitosan. The increased contact angle is ascribed to the decrease of the hydrophilicity of the polyurethanes, which is reduced by the increasing amount of chitosan with respect to dimethylol propionic acid chain extender.     

Selectin Receptors 4: Synthesis of Tetrasaccharides Sialyl Lewis A and Sialyl Lewis X Containing A Spacer Group1,2

ABSTRACT

Synthesis of two isomeric tetrasaccharides, namely Neu5Acα(2→3)Galβ(1→3)[Fucα(1→4)GlcNAcβ (sLe^a) and Neu5Acα(2→3)Galβ(1→4)[Fucα(1→3)]GlcNAcβ (sLe^x) as 3-aminopropyl glycosides is described. Preparation of these compounds was performed by sialylation of selectively protected trisaccharides Le^a and Le^x which contain three unsubstituted OH groups at positions 2, 3 and 4 of Gal residue. Glycosylation of Le^x trisaccharide with ethylthio sialoside under promotion by NIS and TfOH in acetonitrile was effective and regio- and stereoselective to give sLe^x derivative in 81% yield. In contrast, sialylation of the Lc^a acceptor was accompanied by a variety of undesirable by-processes, namely. N-thioethylation of the GlcNAc residue, β-sialylation, and lactonisation. In order to improve the yield of sLc^a tetrasaccharide the glycosylation of Le^a acceptor by sialyl donors of ethyl and phenyl thioglycoside (promoted by NIS-TfOH or NBS-Bu₄NBr), xanthate (promotion by NIS-TfOH mixture or MeOTf) and phosphite (promoted by TMSOTf) types was also studied. Among the reactions investigated the glycosylation by phenyl thioglycoside sialoside promoted by NIS-TfOH gives the best yield (39%) of sLe^a tetrasaccharide product.     

Fullerenes as passivating agents of the surfaces of semiconductor photo- and light-emitting diodes

A new pathway for passivation of the surface of infrared photodiodes and light-emitting diodes operating at room temperature in the spectral range of 2–5 μm by individual fullerene C₇₀ is proposed and its characteristics are studied. It is determined that during the passivation of photodiodes, dark current falls by 40% and resistance at zero bias increases by 24%; for light-emitting diodes, leaks fall by ∼20%, and resistance at zero bias increases by 45% and the intensity of emission of light-emitting diodes increases by ∼18% after the application of fullerene C₇₀.     

Dependence of nanophase separated structure of epoxy hydrogels on swelling conditions investigated by SANS

A hydrophilic non-stoichiometric epoxy network was prepared by end-linking reaction of α,ω-diamino terminated poly(oxypropylene)-b-poly(oxyethylene)-b-poly(oxypropylene) (POP-POE-POP) and diglycidyl ether of Bisphenol A propoxylate (PDGEBA) at the excess of amino groups. Series of epoxy hydrogels swollen to various degrees was prepared by swelling of the epoxy network in D₂O and solutions of inorganic salt (KNO₃) in D₂O, respectively, and investigated by small-angle neutron scattering (SANS). Degree of swelling was controlled in two ways: by partial evaporation of the solvent and by KNO₃ concentration in the swelling solution. Nanophase separated structure of all hydrogels was confirmed by SANS. Scattering data were fitted to the Teubner-Strey model assuming bicontinuous locally lamellar structure of the hydrogels. Changes in SANS profiles induced by the presence of KNO₃ in swelling solutions reflect a refinement of the nanophase separated structure of hydrogels caused by improvement of POE-D₂O interaction by means of breakage of deuterium-bonded structure of D₂O by nitrate anions.     

Effect of crystallization route on the properties of LiMn2O4 thin films prepared by spin coating

LiMn₂O₄ thin films were prepared by spin coating through intermediate amorphous layer route (IALR) and intermediate crystallized layer route (ICLR). The phase identification, surface morphology, and electrochemical properties of the films prepared by different crystallization routes were studied by X-ray diffraction, scanning electron microscopy, and galvanostatic charge–discharge experiments. The results show that both films prepared by different crystallization routes are homogeneous and crack free. Compared with the film prepared by IALR, the film prepared by ICLR shows smaller grain size and is smoother and denser. The LiMn₂O₄ film prepared by ICLR delivers the specific capacity of 39.8 μAh?cm^?2?μm^?1, which is higher than 35.6 μAh?cm^?2?μm^?1 for the one prepared by IALR. The capacity loss of the film prepared by ICLR after being cycled 100 times is 3.4 %, which is smaller than that of 5.5 % for the film prepared by IALR. The film prepared by ICLR shows higher specific capacity and better cycling behavior than the one prepared by IALR.