三氯化钛水溶液与氨基酮在碱性介质中的反应

氨基醇具有一定的镇静生理活性,通常由氨基酮还原制得。β-或α-氨基酮经Al-Hg齐和电化学还原可得到相应的二氨基听呐醇,然而,此法操作不便,产率很低,又具有毒性。我们以甲醇为溶剂,用9种氨基酮盐酸盐1与15％的三氯化钛水溶液在碱性条件和Ar气保护下反应,得到相应的双分子还原产物——二氨基(口片)呐醇,并分离出dl-和meso-异构体。     

The Decay of Methylene Blue in Alkaline Solution

The decomposition of methylene blue in aqueous alkaline solution is described. The rate equation is of the form: , where k = 9.0 × 10^-4 mol^- [dm³s^-1 at 20°C and] = 0.5 mol dm^-3.     

The Crystal Structure of Dimethylamino Titanium Trichloride

Green crystals of Me₂NTiCl₃ associate to a chain polymer via four Ti‐Cl‐Ti bonds and generation of hexacoordinated Ti atoms. Like Et₂NTiCl₃ its amino group is not involved into forming Ti‐N‐Ti bridges. This is due to a short Ti‐N bond to the planar coordinated N atom of the Me₂N group.     

测定抗坏血酸的亚甲蓝褪色光度法

确定了亚甲蓝与抗坏血酸褪色反应的最佳条件,在 pH=2的缓冲溶液和对氨基苯磺酸存在的条件下,抗坏血酸能够很快还原亚甲蓝并使之褪色,褪色反应的体系具有很好的稳定性。该反应的摩尔吸光系数为 2.0× 103 L· mol－ 1· cm－ 1,线性范围 0.4～ 40.0 mg/L。该法具有优良的选择性,常见的能够与抗坏血酸共存的阴、阳离子和还原剂、表面活性剂不干扰测定,应用于药品、饮料、蔬菜中抗坏血酸的测定,获得满意结果。     

光敏剂亚甲蓝与不同溶剂的相互作用研究

应用光谱法研究了新光敏剂亚甲蓝在不同溶剂中的电子光谱特性，通过Ｋａｓｈａ理论推测了其在不同溶剂中二聚体的分子构造模式，其二聚体的面－面间距离为１．３４５～１．４２５ｎｍ，面间角为８２．９°～８７．５°确认由ＭｃＲａｅ式对亚甲蓝与不同溶剂间的相互作用下方式进行评价是可行的，提出了亚甲蓝在不同溶剂中分子间力的相互结合作用导致亚甲蓝在溶液中的结构变化，产生光谱差异的原因，阐述了溶液状态与选择性分子间力的     

时间分辨光谱技术研究亚甲基蓝与小牛胸腺DNA的相互作用

采用时间分辨光谱技术研究了亚甲蓝与小牛胸腺DNA（MB-ctDNA）重水混合体系中MB敏化单态氧（1O2）动力学过程,以此进一步探讨MB与DNA的相互作用。结果表明显示,低浓度ctDNA和高浓度ctDNA的单态氧磷光动力学曲线有着明显不同,这些差异被归结为MB与DNA间结合方式和作用机制的改变。在低浓度ctDNA条件下,MB分子和ctDNA之间形成离子型结合物,MB的吸收带出现显著的减色效应,敏化1O2产量随DNA浓度增加而急剧下降,但ctDNA与1O2没有发生明显的相互作用;而在高浓度DNA时,MB分子和ctDNA之间的相互作用方式转变为以嵌入式结合为主,激发态MB与ctDNA间的能量转移和介质的粘度效应,改变了1O2的动力学特性,大大降低了光敏剂MB敏化1O2的产量,但1O2不为ctDNA所猝灭。这些结果阐明,在MB与DNA的混合体系中,敏化单态氧损坏DNA的Ⅱ型反应不是主要的PDT作用机制。     

亚甲蓝光度法测定羟自由基

利用亚甲蓝被氧化后褪色的机理,使用Fenton试剂与亚甲蓝作用,验证了体系中起氧化作用的是羟自由基,从而建立了亚甲蓝光度法检验羟自由基的方法。试验结果表明,在过氧化氢与亚甲蓝的摩尔比为1~20范围内,亚甲蓝吸光度的降低值与Fenton试剂的加入量呈直线关系,因而可在660 nm处测定亚甲蓝的褪色程度(ΔA)对羟自由基作间接光度测定。试验同时对超声法产生的羟自由基进行了测定,表明羟自由基的生成量与超声时间成正比。     

亚甲蓝与十二烷基硫酸钠变色反应光谱机理

为从分子水平认识亚甲蓝(MB)分子与大分子之间相互作用机理,应用吸收光谱法研究了MB与十二烷基硫酸钠(SDS)之间相互作用机理,考察了乙醇、氯化钠、羟丙基-β-环糊精以及Triton X-100对相互作用的影响。结果表明:MB与SDS之间能发生相互作用形成复合物产生变色反应,乙醇等对相互作用都有影响。认为MB与SDS变色反应机理是在MB与SDS大分子间发生静电相互作用基础上,结合在SDS有序集合体上MB分子定向聚集所引起的。     

Catalytic Spectrophotometric Determination of Titanium(IV) Using Methylene Blue‐Ascorbic Acid Redox Reaction

A highly selective and sensitive catalytic method for the determination of trace amounts of titanium(IV) was developed. The method is based on the catalytic effect of titanium(IV) on the methylene blue‐ascorbic acid redox reaction. The reaction was followed spectrophotometrically by measuring the change in absorbance of methylene blue at 665 nm, 5 minutes after the initiation of the reaction. In this study experimental parameters were optimized and the effect of the presence of various cations and some anions on the determination of titanium(IV) was examined. The calibration graph was linear in the range of 3‐25 ng mL^?1 of titanium(IV). The relative standard deviation for the determination of 10 and 20 ng mL^?1 of titanium(IV) were 2.64% and 1.51%, respectively (n = 8). The detection limit calculated from three times of standard deviation of blank 3S_b was 0.6 ng mL^?1. The method was successfully applied to the determination of titanium(IV) in tap water and ore samples.     

Extraction Spectrophotometric Determination of Trace Chlorine Dioxide with Methylene Blue

Abstract

The coloration reagent - leucomethylene blue, the reduction product of methylene blue, is used to determine the concentration of chlorine dioxide in the presence of Cl₂ and anion species such as OCl^?, ClO₂ ^? and ClO₃ ^?. This simple spectrophotometric method is performed by using the extractant 1,2-dichloroethane at pH 1.3. The linear range of ClO₂ measurement extends to 0.95 mgl^?1 with a detection limit of 0.02 mgl^?1. The presence of chlorine and hypochlorite ion can be masked by oxalic acid. The permissible maximum concentration of ClO₂ ^? is 2.0 mgl^?1, and ClO₃ ^? anion does not interfere with the measurement.     

次甲基蓝褪色光度法测定脱氧核糖核酸

研究了碱性染料次甲基蓝与脱氧核糖核酸的结合反应。在pH8.0～8.5的三羟甲基氨基甲烷-HCl介质中,次甲基蓝于630nm处有最大吸收,随着脱氧核糖核酸加入量的增加,其在630nm处的吸光度显著下降,下降程度与脱氧核糖核酸的量成正比。据此,建立了测定脱氧核糖核酸的新方法,方法的线性范围为0～7mg/L。该方法可用于合成样品分析。     

亚甲基蓝与DNA相互作用的电化学研究

近年来,小分子化合物与DNA相互作用的研究是生命科学研究的热门话题。特别是一些药物和毒物分子与DNA的作用[1-2],如何影响DNA的生理和化学物理性质,如何影响DNA的转译和复制,都是十分重要的课题。在医药研究中,DNA与靶向分子相互作用的研究不仅对阐述一些抗肿瘤、抗病毒药物及     

亚甲蓝双分子聚集体的解离平衡

本通过光主地研究了作为新的光敏剂－亚甲蓝（Ｍｅｔｈｙｌｎｅ Ｂｌｕｅ，ＭＢ）在水溶液中的溶液状态，以及其在不同温度时双分子聚集体的解离平衡，通过差示光谱监测了亚甲蓝在水溶液中，其双分子二聚体在温度３０－６０℃范围内的构成方式的变化：其单分子倾角９α）为４８．３－４６．１°，双分子面间距离（ｒ）为０．５７６－０．５８０ｎｍ，监测了亚甲蓝在水溶液中其单最大吸收波长吸收值随温度的变化，算得其二聚体的解     

溴酚蓝和亚甲蓝双显色体系萃取光度法测定铜

向三元络合物[Cu(phen)_3)BPB的二氯乙烷萃取液中,加入KCN水溶液,形成的[Cu(CN)_2)~-和溴酚蓝离子(BPB)进入水相,向其中加入与BPB颜色相近的亚甲蓝(MB)再进行萃取光度测定。因萃取液中[MB_2BPB)和[Cu(CN)_2)MB两者的吸光作用,使本方法具有很高的灵敏度,ε=1.77×10~5L·mol~(-1)·cm~(-1)。铜含量在0～5μg/25ml遵从比耳定律,对含铜量为10~(-8)g/ml的水样测定5次,相对标准偏差为2％。     

亚甲基蓝在云母表面吸附状态的研究

利用XPS测定吸附前后亚甲基蓝（MB）各原子的电子结合能的变化,以判断原子化学环境的改变,从而确定MB在云母表面的吸附位点是二甲胺基上的氮原子.通过AFM测量得到吸附于云母表面的MB分子的平均高度为0.820 nm,这证实了Hähner吸附模型的正确性,即MB分子的最大横截面以65～70°倾斜在云母的（001）表面上.     

Characterization of Titanium Dioxide Doped with Nitrogen and Sulfur and its Photocatalytic Appraisal for Degradation of Phenol and Methylene Blue

The degradation of organic dyes in the presence of modified TiO₂ is still under intensive investigation. We report here an evaluation of the photocatalytic activity of nitrogen‐ (N‐) and sulfur‐ (S‐) doped TiO₂ for the degradation of phenol and methylene blue (MB). N‐doped TiO₂ (N–TiO₂), S‐doped TiO₂ (S–TiO₂), and N–S‐doped TiO₂ (N–S–TiO₂) were prepared using the sol–gel method. The photocatalytic activity was evaluated in a batch reactor using phenol and MB as models of pollutants. In addition, this investigation was performed using a household lamp as the visible light source. Properties of the synthesized materials in terms of Brunauer–Emmett–Teller (BET) surface analysis, field emission scanning electron microscopy (FESEM), Fourier transform infrared spectroscopy (FTIR), and photocatalytic ability were examined. Our study shows that N–S–TiO₂ exhibits better photocatalytic degradation ability for all the considered dyes compared to the other doped TiO₂ materials. In conclusion, we have successfully prepared and evaluated the photocatalytic activity of N‐ and S‐doped TiO₂ for the degradation of phenol and MB using an ordinary household lamp.     

亚甲基蓝溶液中分子二聚现象的压致增强研究

通过原位高压紫外-可见吸收光谱研究了2种溶剂(水溶液和体积比为4∶1的甲醇-乙醇混合溶液)中亚甲基蓝(MB)分子聚集平衡状态的变化.采用金刚石对顶砧原位高压实验装置,在不同压力下测量亚甲基蓝溶液的吸收光谱,最高实验压力分别达到0.8 GPa(水溶液)和8.7 GPa(甲醇-乙醇溶液).结果表明,随着压力的上升,亚甲基蓝溶液中单体分子和二聚体的吸收峰强度比不断下降,说明高压可以促进二聚体的形成,使亚甲基蓝溶液中分子的单体-二聚体动态平衡过程向二聚体方向移动.卸压后,亚甲基蓝溶液吸收光谱的强度降低,但吸收峰的强度比及峰位恢复到加压前的状态,表明高压下分子聚集平衡状态的变化是可逆的.     

亚甲基蓝共振光谱散射法测定脱氧核糖核酸

基于脱氧核糖核酸（ＤＮＡ）对有机染料亚甲基蓝的共振光散射的增强效应,拟定了一种测定了ＤＮＡ的共振光散射法。在ＰＨ５．５－７．５范围内,亚甲基蓝在３５０ｎｍ处的共振光散射增强有度呈线性关系,线性范围为２００－１４００μｇ／Ｌ,检出限可达１５μｇ／Ｌ。该方法简便,快速,用于合成样品中ＤＮＡ的测定,结果令人满意。     

SDS胶束体系中亚甲蓝与血清白蛋白的相互作用

The interaction of methylene blue(MB) and bovine serum albumin(BSA) is investigated in the SDS micelle system which is simulated as one kind of coexisted albumin. The interaction parameters of MB and BSA and simulated albumin such as partition coefficient 辍ormal binding free energy 腉、average binding number n are calculated. The results show that most of MB is in the form of monomer in SDS micelle systems;the main interaction of MB and BSA is of static electric and H bind force,and that of MB and simulated albumin is only of static electric force.     

Modeling and Thermodynamics of Methylene Blue and Acid Blue 80 Adsorption onto Potato Residue Based Activated Carbon

A study was made on the adsorption kinetics and thermodynamics of methylene blue(MB) and acid blue 80(AB80) onto powder of activated carbon(PAC) prepared by chemical method from dry potato residue(DPR). The PAC was characterized by N₂ adsorption-desorption isotherms analysis and scanning electron microscopy. The ma- ximum adsorption capacities of PAC for MB and AB80 at 303 K are 532.19 and 156.22 mg/g, respectively. The results indicate that the adsorption kinetics of the selected dyes on PAC is well-described by the pseudo-second order model. And their thermodynamic data were analyzed via the isotherms of Langmuir, Freundlich, Redlich-Peterson, Toth and Sips, and the thermodynamic parameters were calculated. The results show that PAC is a fast and effective adsorbent for removing the cationic dyes from aqueous solutions.