镁离子型Birnessite的合成和表征

采用ＭｎＯ－４和Ｍｎ２＋在强碱性条件下制得层状结构的Ｍｇ＿Ｂｉｒｎｅｓｓｉｔｅ，用ＸＲＤ（Ｘ射线多晶粉末衍射）、ＦＴ－ＩＲ（傅里叶红外光谱）、ＴＧ－ＤＴＧ／ＤＴＡ（热失重－微商热失重／热分析）等方法对它进行了表征。Ｍｇ＿Ｂｉｒｎｅｓｉｔｅ在２００～４００℃时为无定形，在６００℃生成结晶良好的Ｍｎ２Ｏ３相。ＣＣｌ４、ＣＨ３ＯＨ、ｎ＿Ｃ６Ｈ１４的吸附等温线类似于第三种类型的吸附等温线，在接近饱和的情况下都有凝聚现象产生。在６００℃，比表面和吸附数据表明出现层状结构塌陷。吸附吡啶ＦＴ－ＩＲ谱表明在Ｍｇ＿Ｂｉｒｎｅｓｉｔｅ中存在非质子酸（Ｌ酸）和质子酸（Ｂ酸）酸位。     

纳米铋酸钠的合成及其结构表征

采用次氯酸钠浓溶液在强搅拌条件下和强碱性环境中氧化硝酸铋,得到纳米铋酸钠晶体.研究结果表明,反应过程中的中间产物氢氧化铋的粒度及分散性能是影响铋酸钠制品的粒度及分散性能的关键因素.研究了次氯酸钠浓度、硝酸铋浓度和反应时间对纳米铋酸钠制品的粒度和纯度的影响,得出了最佳的合成条件.采用化学分析、TEM、IR、TG-DSC和XRD等测试手段证实样品的化学组成为NaBiO₃·2H₂O,是粒径为30～50nm的纳米级鳞片状晶体.     

The Preparation and Characterization of Conjugated Linolenic Acid

Conjugated Linolenic Acid (CLN) has recently been shown to have a more strong cytotoxic effect on various human tumor cell lines than CLA. In CLN, all the three double bonds are conjugated, whereas they are methylene-interrupted in LN. Some seed oil, such as tung oil and pomegranate seed oil, principally consist of CLN, accounting for 76.5% and 75.5%, respectively.CLN can be characterized using the combination of gas chromatography (GC), highperformance liquid chromatography (HPLC) and UV /VIS spectrophotomea-ic analysis. GC can separate the CLN from other fatty acids and HPLC can separate the individual CLN isomers.The conjugated triene formation has a maximum absorbency at 268 nm and the conjugated diene formation has an absorbency at 235 nm in UV spectrum.CLN was prepared from linseed oil by isomerization reaction in our present study. By treating at was isomerized and the product was purified by recrystallizing in the methanol. The GC and UV /VIS spectrophotometric analysis were used to characterize the obtained products. It was found that the a-LN in the linseed oil was converted to the corresponding conjugated diene acids and CLN. The GC analysis also showed that there formed about 20% CLN when reacting for 10h with 40% KOH/ethylene glycol.     

Sorbic Acid and Its Degradation Products: Electrochemical Characterization

The electrochemical redox behavior of sorbic acid (SA), an important food preservative, was investigated at a glassy carbon electrode using cyclic, differential pulse, and squarewave voltammetry over a wide pH range. The oxidation of SA is an irreversible, diffusion-controlled, and pH-independent process that occurs with the transfer of only one electron and does not involve the formation of any electroactive oxidation product. Adsorption of SA at GCE electrodes was also observed. Following incubation in different pH electrolytes, the degradation of SA was electrochemically detected by the appearance of a new oxidation peak at lower potential value. The degradation products, formed homogenously in solution, undergo irreversible oxidation and lead to the formation of two oxidation products that strongly adsorb on the electrode surface and are reversibly oxidized. SA degradation was also confirmed using HPLC and UV-Vis spectrophotometry. A mechanism for oxidation of SA and its degradation products in aqueous solutions was proposed.     

A New Application of N,N ′-dibromo-N,N ′–1,2-ethanediylbis(p-toluenesulfonamide) as Selective and Efficient Reagent for the Oxidation of Various Thiols to Disulfides

ABSTRACT

An efficient method for oxidation of thiol to their corresponding disulfides in high yields with N, N^′-Dibromo-N,N^′–1,2-ethanediyl bis (p-toluensulphonamide) in dichloromethane at room temperature is described.     

石墨烯薄膜的制备和结构表征

采用氧化还原法制备了石墨烯胶状悬浮液, 通过真空抽滤获得了石墨烯薄膜. 利用X射线衍射(XRD)、傅里叶变换红外(FTIR)光谱、拉曼(Raman)光谱、粒度分析和扫描探针显微镜(SPM)等研究了石墨烯薄膜制备过程中各阶段产物的晶体结构、粒度及分子光谱特征变化. FTIR分析结果表明, 石墨在氧化过程中结构层键合大量含氧官能团, 还原后结构层表面仍残存有部分稳定的含氧官能团. XRD结果表明, 石墨氧化后衍射峰向小角度偏移、宽化, 原有石墨峰消失. 在成膜过程中氧化石墨烯形成凝聚体,而石墨烯形成絮凝体. 粒度分析和SPM测试分析结果表明, 氧化石墨烯在水中粒径分布呈拖尾峰形, 分布范围较宽. 石墨烯在水中的粒径成单峰分布, 分布范围较窄、对称性较好且平均粒径较小. Raman测试结果表明, 石墨在氧化和还原过程中, D、G峰逐渐宽化, I_D/I_G逐渐增强, 样品无序度增加. 在以上分析的基础上对石墨烯制备过程的结构特征进行了归纳总结.     

One-Pot Synthesis of Thiazoles from Pyridazin-3-hydrazidic Acid Derivatives

Several new thiazole derivatives have been synthesized; the reactivity of these compounds toward amines, aldehydes, and hydroxyl amine are reported. New syntheses of pyrimidino[5,4:3,4]pyrazolo[4,3:5,6]pyridazine derivatives also have been achieved.     

Oxidative transformation of thiols to disulfides promoted by activated carbon-air system

Efficient oxidative transformation of thiols to disulfides took place in the presence of activated carbon under an oxygen (or air) atmosphere. The present oxidation method is available not only for a variety of thiols such as simple aromatic and aliphatic thiols but also for 3,4-dihydropyrimidin-2(1H)-thiones and N-Boc-l-cysteine.     

酸法制备杨木微/纳纤丝及其表征

近二十多年来,如何从天然纤维素中分离微/纳纤丝和用其来增强高分子聚合物受到许多学者的关注。本研究以杨木纤维素为原料,采用硫酸和盐酸的混合液水解、恒温水浴振荡处理制备杨木微/纳纤丝。利用扫描电子显微和X射线衍射仪对制备的杨木微/纳纤丝进行分析表征,结果表明当酸处理条件为杨木纤维3g、浓H2SO4体积分数为15%、浓HCl体积分数为5%、恒温水浴60℃、振荡8h,可得到杨木微/纳纤丝,杨木微/纳纤丝宽度分布在200nm到1μm之间,长宽比约60~120,相度结晶度为77.59%。     

稀土烟酸与8-羟基喹啉三元配合物的合成、表征及荧光光谱

合成了 4种稀土烟酸 (HL)与 8 羟基喹啉 (Hhq)的三元固体配合物 ,对它们进行元素分析 ,确定其通式为REL2 ·hq·2H2 O (RE =La ,Eu ,Tb ,Dy) ,用摩尔电导、TG DTA分析、IR、UV和荧光光谱等研究了配合物的有关性质。结果表明 ,烟酸脱掉羧酸上的质子以酸根的形式与稀土离子呈双齿配位 ,而吡啶环上的氮原子未参加配位。hq- 的羟基氧和杂氮原子与RE3+ 离子配位。配体与稀土配位后 ,配合物中稠环数目增多 ,π键共轭程度增大。配合物中所含的水可能为配位水。荧光光谱研究发现 ,La和Dy的配合物的荧光表现为配体的荧光 ,Eu配合物中心离子的特征荧光峰表现不明显 ,而Tb配合物中配体能有效地将吸收的能量传递给Tb3+ ,敏化Tb3+ 的发光 ,发射较强荧光     

稀土间氨基苯甲酸8-羟基喹啉三元配合物的合成、表征及抑菌作用研究

以稀土氯化物、间氨基苯甲酸和8-羟基喹啉为原料, 无水乙醇为溶剂, 首次制备了8种稀土-间氨基苯甲酸-8-羟基喹啉固体配合物. 经元素分析、紫外光谱、红外光谱、热重-差热分析和摩尔电导测定,确定了配合物的组成、性质和成键特征, 其组成为RE(MABA)(hq)2(RE=La3+, Ce3+, Pr3+, Nd3+, Sm3+, Eu3+, Er3+, Y3+; hq=C9H6NO-;MABA-=C6H5NH2COO-). 热分析表明, 配合物的热稳定性优于配体. 试验了该系列配合物的抑菌活性, 结果发现稀土三元配合物的抑菌效果比单独的稀土氯化物、间氨基苯甲酸、 8-羟基喹啉的抑菌效果好.     

Synthesis of 8-arylsulfoxyl/sulfonyl adenines

We report a method for the synthesis of 9-N-alkyl-8-arylsulfoxyl adenines and 9-N-alkyl-8-arylsulfonyl adenines. The approach starts with a tandem one-pot reaction that by using Mitsunobu conditions converts 8-arylsulfanyl adenines to the corresponding iminophosphorane protected 9-N-alkyl-8-arylsulfanyl adenines. These compounds were further subjected to selective OXONE^®/alumina mediated oxidation followed by deprotection of the amine leading to the desired sulfoxides and sulfones.     

6-马来酰亚胺基己酸的合成与表征

以氨基己酸和马来酸酐为原料,乙酸酐、乙酸钠作催化剂,在室温下反应5h,合成了一种新的可用于蛋白质、多肽药物修饰的“间隔臂”6-马来酰亚胺基己酸,产率90．34％,其结构经。HNMR,IR和LC-MS表征。     

6-氨基己酸的合成与表征——综合性多步有机合成实验

介绍了以环己酮为原料,通过肟化、贝克曼重排和水解开环等3步合成6-氨基己酸的过程,样品经过纯化后,通过1H NMR和13C NMR确证结构。本实验和有机合成课程结合紧密,内容覆盖肟化、重排、水解开环等基本操作,适合作为学生综合实验。     

Synthesis and Characterization of Amino Acid Modified Chitooligosaccharides

Amino acid modified chitooligosaccharides were synthesized by the new synthetic route. The chloroacetyl-chitooliogosaccharide intermediates were prepared under a mild condition via a reaction between chitooligosaccharide (COS) and chloroacetic anhydride. The intermediates were subsequently reacted with a variety of amino acids, e.g., glycine, aspartic acid, alanine, arginine, and serine, under a basic condition, yielding amino acid modified COS products. The degree of chloroacetylation was calculated based on new ¹H NMR absorption peaks at 3.80 and 3.94 ppm, corresponding to  NH CO CH₂ Cl and  O CO CH₂ Cl, respectively. The degrees of chloroacetylation determined were 0.40, 0.44, 0.62, and 0.93 when the mole ratios of chloroacetic anhydride to COS were 0.5, 1, 2, and 4, respectively. The chemical structures of the COS derivatives were also determined using ¹H NMR spectroscopy. The biological properties of the derivatives were evaluated. Cytotoxicity of the derivatives was assessed by a direct contact, using L929 cells. An MTT assay was a method of choice to evaluate the efficacy of the derivatives to enhance the proliferation of L929 cells.     

新型丙烯酸共聚物的合成与表征

以生物试剂磷酸烯醇式丙酮酸钾（PEPK）、丙烯酸（AA）为聚合单体,采用Na2S2O8-Na2S2O5氧化还原引发体系进行温和的水溶液聚合反应,通过平行合成得到了a、b、c 3个系列的PEPK-AA共聚物。通过红外光谱（FT-IR）、核磁共振（13C-NMR）以及共聚物分子量的测定,表征了PEPK-AA共聚物的化学结构...     

乙醇酸和DL─乳酸交替共聚物的合成和表征

乙醇酸和ＤＬ－乳酸交替共聚物具有不同于其无规共聚物的理化性能和生物降解性。以ＤＬ－３－甲基－１，４－二烷－２，５－二酮为单体，通过在辛酸亚锡引发下的本体开环聚合，合成了该交替共聚物，并进行了结构表征。     

以二茂铁二羧酸为配体的锌配位聚合物[Zn(Py)2L]n的合成与晶体结构

具有金属有机框架的配位聚合物与以往的以硅酸盐、硅铝酸盐和磷铝酸盐作为骨架的沸石和分子筛微孔晶体材料不同，是利用具有多齿配位能力的有机多酸或多碱和金属离子作为结构单元构筑的无机-有机杂化微孔晶体材料。这类新结构在选择性催化、分子识别、可逆性主客体分子(离子)交换、超高纯度分离、光电材料和磁性材料等新型功能材料的开发中显示了广阔的应用前景。