3,5-二硝基苯甲酸冰片酯的合成及结构表征

冰片在中药中被广泛应用。利用前药原理,对冰片母体进行修饰,以冰片和3,5-二硝基苯甲酸为原料,以对甲苯磺酸为催化剂,合成了3,5-二硝基苯甲酸冰片酯,目标化合物的结构经FT-IR、13C NMR、1H NMR和元素分析加以确证。该化合物具有一定的研究开发价值。     

有机酸在γ-Al~2O~3表面自发单层分散及苯甲 酸-γ-Al~2O~3表面结构的研究

有机酸如苯甲酸,水杨酸,邻-或对-苯二甲酸,酒石酸均可在γ-Al~2O~3表面自发单层分散,分散的临界温度取决于有机酸分子中极性基团的数目和极性的强弱。XRD,Raman,FT-IR,UV-vis和TG对苯甲酸-γ-Al~2O~3体系的表征结果表明,苯甲酸在室温下即可在γ-Al~2O~3表面自发单层分散;分散后,苯甲酸分子间的氢键缔合结构垮塌;苯甲酸的羧基与γ-Al~2O~3表面羟基发生相互作用并缩水形成类似羧酸盐的结构;分子中的苯环与载体表面没有直接的相互作用。XRD相定量测得的分散阈值为1.1mmol苯甲酸/100m^2γ-Al~2O~3,与按苯环垂直表面计算所得的最大分散容量1.2mmol/100m^2相近。     

Solvent free reactions

Reactions of nitrophenols have been studied in the eutectic melt of 8-hydroxyquinoline–benzoic acid, where it reacted with 8-hydroxyquinoline. The reactions were also carried out in solution. The reaction products obtained from both the methods were characterized by FT-IR, differential scanning calorimetry, X-ray diffraction technique and microstructural investigations. The reaction products obtained from eutectic melt were analyzed for C, H, N. The results showed that reaction products obtained from both the methods are same. An attempt has been made to propose the overall mechanism of the reaction in the eutectic melt.     

Infrared spectroscopy of goethite dehydroxylation. II. Effect of aluminium substitution on the behaviour of hydroxyl units

Dehydroxylation of goethite as affected by aluminium substitution was investigated using Fourier transform infrared spectroscopy (FT-IR) in conjunction with X-ray diffraction (XRD), thermogravimetric analysis (TGA) and differential thermogravimetric analysis (DTGA). The band intensities of hydroxyl vibrations were indicative of the degree of dehydroxylation and the changes in band parameters due to aluminium substitution were observed. The effect of aluminium substitution on band parameters of FT-IR spectra of goethite and its partially and fully dehydroxylated products, the mixture of goethite/hematite and hematite, were interpreted. The results of this study have confirmed that aluminium substituted goethite is thermally more stable than non-substituted goethite and is in harmony with the results of XRD and DTGA. A larger amount of non-stoichiometric hydroxyl units is associated with a higher aluminium substitution. A shift to a higher wavenumber of bending and hydroxyl stretching vibrations is attributed to the effects of aluminium substitution associated with non-stoichiometric hydroxyl units on the a-b plane relative to the b-c plane of goethite. The results provide information for the characterisation of activated bauxite containing hematite and goethite.     

Synergistic effect of Zr-incorporated framework and subsequent deposition of PEHA towards efficient and reusable HPW/PEHA/ZrSBA-15 composites

Heteropolyacid-based catalysts with molecular level distributions of surface functionalities were synthesized by anchoring phosphotungstic acid (HPW) onto the pentaethylenehexamine (PEHA) layers stabilized by platelet ZrSBA-15 with short mesochannels. Namely, the presence of zirconium species in pore walls could significantly improve the surface acidity to attract and stabilize PEHA species, leading to a stronger interaction between them and a superiority to make HPW species highly stable. Standard characterizations of XRD, SEM, TEM, FT-IR, TG, N₂ adsorption–desorption and N elemental analyses were preserved to demonstrate the synergistic effect. The resulting composite were investigated for the oxidation of benzaldehyde to benzoic acid in the H₂O₂-mediated environment, the catalyst 25 % HPW/PEHA/ZrSBA-15 screened high yield for benzoic acid (~99.7 %). Besides, various reaction parameters such as reaction temperature, reaction time, the amount of hydrogen peroxide and catalyst reusability were also investigated for the oxidation of benzaldehyde to benzoic acid with a target to confirm the validity of the catalyst.     

Identification of salicylic acid using surface modified polyurethane film using an imprinted layer of polyaniline

The surface of polyurethane (PU) was modified by coating a thin layer of polyaniline (PAN) by oxidizing aniline using ammonium persulfate. Affinity sites for salicylic acid (SA) were created in the coated layer by non-covalent imprinting method. The imprinted layer adsorbed SA five times more compared to the nonimprinted surface reflecting the creation of affinity sites specific to SA on the surface. The equilibrium was attained relatively faster indicating that a material of this kind is suitable for sensing applications. The selectivity in recognizing the print molecule by the imprinted surface was assessed by comparing the extent of uptake of other structurally resembling molecules namely O-amino benzoic acid and acetyl salicylic acid. The selectivity factor was found to be 22 and 16.5. The adsorbed SA was detected using the technique of Fourier transform attenuated total internal reflection infrared spectroscopy (FT-ATR-IR). The results show that molecularly imprinted surface in combination with FT-IR is a useful approach for the sensing applications.     

Acidity and Catalytic Activity of Phosphoric Acid Modified Titanium Oxide Surface

By refluxing the anatase form of TiO₂ powder in phosphoric acid, the surface acidity was observed to increase. The amount of acid was determined by n-butylamine titration in n-heptane media, and was found to be proportional to the reflux period in phosphoric acid. XRD patterns and IR spectra revealed that the products contained a mixture of the anatase form of TiO₂ and titanium phosphate phases. Based on the calculated acid density on the surface, part of the titrant, n-butylamine penetrated into the titanium phosphate layers. Further investigations using TGA, FT-IR and TEM techniques along with surface area measurements indicated that the titanium phosphate phase was coated over the TiO₂ phase. The surface acidity of the phosphoric acid treated anatase increased due to the substitution of Ti-OH groups by phosphate groups. Nevertheless, the chemical properties of the resultant surfaces were found to be influenced by the internal anatase phase. The kinetic data on the 2-propanol dehydration reaction, where the activation energies were found to decrease gradually with an increase in phosphate content, also support these conclusion.     

The mechanism of the sonochemical degradation of benzoic acid in aqueous solutions

The sonolytic degradation of benzoic acid in aqueous solution was investigated at an ultrasonic frequency of 355 kHz. The degradation rate was found to be dependent upon the solution pH and the surface activity of the solute. The degradation rate was favoured at a solution pH lower than the pK _a of benzoic acid. At pH < pK _a, HPLC, GC and ESMS analysis showed that benzoic acid could be degraded both inside the bubble by pyrolysis and at the bubble/solution interface by the reaction with OH radicals. At higher pH (> pK _a) benzoic acid could only react with OH radicals in the bulk solution. During the sonolytic degradation of benzoic acid, mono-hydroxy substituted intermediates were observed as initial products. Further OH radical attack on the mono-hydroxy intermediates led to the formation of di-hydroxy derivatives. Continuous hydroxylation of the intermediates led to ring opening followed by complete mineralization. Mineralization of benzoic acid occurred at a rate of < 40μM/h.     

双活性磺酸基蔗渣木聚糖对羟基苯甲酸酯的合成及活性模拟

以蔗渣木聚糖(BX)为主要原料、氨基三磺酸钠为酯化剂,在一步酯化合成磺酸基蔗渣木聚糖酯的基础上,利用磺酸基蔗渣木聚糖酯和对羟基苯甲酸进行二步酯化反应,合成了磺酸基蔗渣木聚糖对羟基苯甲酸酯,并考察了反应条件对酯化反应的影响,通过单因素实验确定了第二步酯化反应较佳的合成工艺条件.蔗渣木聚糖酯化改性前后的样品分别用FT-IR,DG-DTG和XRD进行了表征,并对该双酯化衍生物的分子进行了优化与活性模拟.结果表明:FT-IR证明双酯化产物含有磺酸基团和对羟基苯甲酸酯基团,TG-DTG分析表明该双酯化衍生物的热稳定性提高,XRD说明发生双酯化改性后分子排列的规整性提高,结晶度增加;活性模拟实现了磺酸基蔗渣木聚糖对羟基苯甲酸酯与艾滋病毒的对接.     

Material Balance Study of Adsorption of Organic Compounds

It was shown that the structure of a surface complex and the nature of an adsorption bond can be determined from the material balance of adsorption of H⁺and OH^–ions and organic compound. A calculation procedure was considered using adsorption of benzoic acid on silica gel and zirconia as examples. It was established that adsorption of benzoic acid on silica gel was accompanied by the release of H⁺ions resulted from the formation of surface hydrogen bonds, whereas adsorption on zirconia, by the substitution of OH^–ions in coordination sphere of Zr(IV).     

Separation and identification of photodegradation products of benzoic acid by capillary zone electrophoresis

A capillary zone electrophoresis (CZE) method was developed for separation and identification of photodegradation products of benzoic acid under irradiation at a wavelength of 300 nm. Parameters such as run buffer, applied voltage and injection time were optimized for the separation of benzoic acid and its photodegradation products. Linearity, limit of detection, and repeatability of migration time as well as peak area of the method were examined. Four reaction products, including salicylic acid, 3-hydroxybenzoic acid, 4-hydroxybenzoic acid and 3,4-dihydroxybenzoic acid have been separated and identified by spiking the known compounds into the irradiated samples using the CZE method developed. The confirmation of the reaction products is one of the key steps for proposing the possible reaction mechanisms involved in the photodegradation of benzoic acid.     

Heat-resistant pyridine-based poly(ether-ester)s: Synthesis, characterization and properties

A pyridine-based diacid was synthesized via nucleophilic substitution reaction of 4-hydroxy benzoic acid with 2,6-dichloropyridine in the presence of potassium carbonate. The diacid was characterized using FT-IR and 1H-NMR spectroscopic methods and also with elemental analysis. Polycondensation reaction of the diacid with different diols including 1,4-dihydroxy benzene, 1,5-dihydroxy naphthalene, bis-phenol A and bis-phenol-P resulted in preparation of pyridine-based poly(ether-ester)s. The polymers were characterized and their physical and thermal properties including inherent viscosity, molecular weight, solubility, thermal stability, thermal behavior and crystallinity were studied. They revealed high heat-resistance and improved solubility in polar solvents. Structure-property relations for the prepared polyester were also studied.     

Efficient approach for the diversity-oriented synthesis of macro-heterocycles on solid-support

The generation of macro-heterocycles starting from resin bound orthogonally protected lysine and using nucleophilic aromatic substitution is described. The method of cyclization required the coupling of o-fluoro-p-nitro benzoic acid followed by intramolecular displacement of the fluoro group. The described method allows a versatile synthetic route to the synthesis of libraries of macro-heterocycles in an attempt to establish lead drug candidates. The desired cyclic products were obtained in good yields and purities.     

N-琥珀酰壳聚糖的合成和性能研究

通过控制反应时间，制备了一系列取代度不同的N-琥珀酰壳聚糖。测定了产物的取代度、特性粘数、吸湿与保湿性，并用IR进行了结构表征。结果表明：壳聚糖在C2位上引入了琥珀酰基后可溶于水，其吸湿性与保湿性随取代度的增加而增强，且优于壳聚糖和透明质酸。     

纤维素在离子液体[AMMor]Cl/[AMIm]Cl混合溶剂中的均相乙酰化反应研究

利用混配离子液体N-烯丙基-N-甲基吗啉氯盐(N-allyl-N-methylmorpholinium chloride,[AMMor]Cl)和1-烯丙基-3-甲基咪唑氯盐(1-allyl-3-methylimidazolium chloride,[AMIm]Cl)作为溶剂,乙酰氯为乙酰化试剂,研究了在没有催化剂条件下的纤维素的均相乙酰化反应.生成的醋酸纤维素(CA)的取代度由2.58到3.00.用FT-IR,1HNMR和13CNMR进行表征.结果表明,[AMMor]Cl/[AMIm]Cl混配的离子液体是一种良好的均相乙酰化介质,纤维素C-6,C-3和C-2三个位置上的羟基均发生了乙酰化反应,且得到纯的纤维素醋酸酯.此反应方便可控,简单高效,不仅降低了成本,离子液体比较容易回收,可以再次利用.     

某些有机物在氧化物载体表面的自发单层分散

自发单层分散原理已在载负型催化剂制备、再生等方面得到越来越广泛的应用[1，2]．许多氧化物和盐类可以在载体表面形成单层分散或亚单层分散．有些分散物与载体混合后在低于其熔点的温度下处理，就可以自发分散到载体表面[1，3]．这一现象通过XRD、LRS、XPS、SIMS、ISS、EXAFS     

肝靶向海藻酸钠载药纳米粒的细胞毒性研究

本研究将具有肝靶向性分子甘草次酸（GA）偶联在具有生物相容性和生物可降解性的天然高分子海藻酸钠（ALG）上,合成了甘草次酸改性的海藻酸钠（GA—ALG）;对广谱抗癌药物阿霉素（DOX）进行包封,制备了肝靶向载药纳米粒,并考察了GA—ALG载药纳米粒的体外释药性能和对肝癌细胞的抑制作用．利用核磁、红外和元素分析技术对GA—ALG结构和GA取代度进行了表征;对GA—ALG载药纳米粒的形貌、粒径、表面Zeta电位等进行了测定,结果显示纳米粒具有较规则球形结构,其水合粒径为（214±11）nm．GA—ALG载药纳米粒在模拟生理条件下（pH7．4）可持续释药长达20天;MTT结果显示GA-ALG载药纳米粒对7703肝癌细胞的具有明显的杀伤作用．     

Kinetics of bulk polymerization of trimeric phosphonitrilic chloride

The kinetics of the pure bulk polymerization of trimeric phosphonitrilic chloride were investigated in the temperature range 240–255°C. The reaction was found to be secondorder with an activation energy of 57 kcal./mole. Polymerization catalyzed by benzoic acid was first-order, and the reactivities of benzoic acid and sodium benzoate at 235°C. were found to be about similar. The volatile decomposition products for the benzoic acid reaction were identified. Mechanisms are postulated for the catalyzed and uncatalyzed reactions.     

铽-芳香羧酸-丙烯腈三元配合物的合成及发光性能

铽-芳香羧酸-丙烯腈三元配合物的合成及发光性能;铽;芳香羧酸;丙烯腈;三元配合物;发光性能     

ADSORPTION BEHAVIOUR AND RHEOLOGICAL PROPERTIES OF NON-AQUEOUS LANTHANUM CHROMITE SUSPENSIONS

Adsorption studies of monosubstituted benzene molecules with various functional groups on doped lanthanum chromite/cyclohexane surface have been performed. The results from the adsorption study can be used in selecting appropriate anchoring groups on the dispersant. It was found that high amount of O relative lo La on the LaCrO₃ surface correlated with high amounts of adsorbed benzoic acid. Increase in the La content relative to the O on the powder surface increased the amount of adsorbed benzylamine. The high amount of benzoic acid adsorbed on 20% Ca-doped lanthanum chromite powder (Al)lated well with good colloidal stability caused by a carboxylic acid containing dispersant. Rheology experiments showed that a low degree of agglomeration is obtained using only a small amount of the carboxylic acid containing dispersant (Hypermer LP1). Etectrophoretic mobility measurements in water of this powder coated with the LP1 dispersant indicated electrosteric stabilisation.