活性氧对品红甲亚胺染料光褪色过程的影响

活性氧对品红甲亚胺染料光褪色过程的影响冀亚飞石俊英（安徽省药物研究所，合肥２３００２２）（华东理工大学精细化工系，上海２００２３７）陈志文（中国科技大学结构分析开放研究实验室，合肥２３００２６）品红甲亚胺染料（ＭＡＤ）是彩色感光材料经曝光和彩色显影后...     

品红甲亚胺染料光褪色机理研究（Ⅰ）：—与活性氧的反应能力

用紫外－可见吸收光谱和高效液相色谱研究了品红甲亚胺染料（MAD）的光褪色过程，结果表明：MAD本身不是产生活性氧（^O2,O^-2)的敏化剂，而是一个良好的活性氧的受体。敏化剂亚甲基兰（MB）孟加拉玫瑰 （RB）所产生的活性氧都对MAC的褪色有贡献，用竞争动力学实验，以二苯基苯并呋喃为竞争反应的标准物质，测定了MAD与活性氧反应的总反应速率常数（k=8.50×10^7L/mol.s)和化学反应速率常数（kR=1.49×10^7L/mol.s)结果发现猝灭过程以物理猝灭为主，RB工MB敏化MAD光氧化实验表明，^1O2是导致MAD光氧化色的主要原因。     

品红甲亚胺染料影像光稳定性的研究——抗氧化剂和单重态氧的反应能力及其对染料影像光褪色的影响

本文研究了苯酚类(A),双酚类(B),对苯二酚类(C),色满类(D)和双螺色满类(E)抗氧化剂的性能。通过循环伏安法测定了它们的氧化电位;用类似Stern-Volmer关系图求得各抗氧化剂和单重态氧的反应速率常数。抗氧化剂的氧化电位越小,和单重态氧的反应速率常数越大,对品红甲亚胺染料影像的防褪色效果越好,进一步证实了染料褪色的光氧化反应机理。在这些抗氧化剂中,它们的防褪色效果依次为D>E>C>B>A。     

品红甲亚胺染料影像光稳定性的研究 Ⅱ.抗氧化剂猝灭单重态氧的反应速率常数测定

本文利用高效液相色谱法测定了色满类,双螺色满类,对一甲氧基苯酚类和双螺茚类抗氧化剂与单重态氧反应的物理猝灭速率常数和化学猝灭速率常数。实验结果表明,抗氧化剂猝灭单重态氧的过程以物理猝灭为主,物理猝灭速率常数和总猝灭速率常数愈大,品红甲亚胺染料的防褪色效果愈好,但存在一极限褪色率。     

品红褪色的课外探究性实验

就一次SO2使品红褪色的演示实验中出现的异常褪色现象,指导学生展开了课外探究性实验,对SO2,NaOH等使品红褪色的机理进行了合理的解释。     

品红褪色机理的实验探究

中学阶段常用于检验二氧化硫气体的品红溶液分为酸性品红和碱性品红2种。通过设计集演示、对比于一体的绿色环保二氧化硫性质实验装置,优化实验条件,探讨了酸性品红和碱性品红与SO2、酸碱反应的性质差异及褪色机理,并提出鉴别酸性品红和碱性品红的简便办法。     

阳离子染料在真丝绸上的光褪色机理

用电化学循环伏安法研究真丝绸上染料的光褪色，发现真丝绸中的某些氨基酸和染料、氧分子３者间可以形成电荷转移复合物。这些三元电荷转移复合物的还原电位比染料本身的还原电位明显正移。用的光照射，证明是真丝绸中的氨基酸加速了阳离子染料的光褪色。     

有机染料光褪色机理及主要原因

本文综述了有机染料光褪色机理的主要研究方法以及现有研究结论.对光氧化和光还原过程、影响因素、典型反应步骤、研究手段进行了系统的阐述,同时也对通过染料分子结构设计合成、通过添加剂的使用提高染料光牢度的方法进行了介绍.     

含吡喃翁端基的不对称三甲川染料合成及光性能

合成了八个新的含吡喃翁端基的不对称三甲川染料，通过元素分析，ＩＲ光谱及１Ｈ－ＮＭＲ谱确证了这些化合物的结构。最大吸收波长在６３０－６８０ｎｍ，有大的半峰宽。     

三甲基品红与脱氧核糖核酸作用的共振光散射光谱的研究

在pH为0.85的三羟甲基氨基甲烷和盐酸 (Tris-HCl)缓冲溶液中 ,三甲基品红(NM)与脱氧核糖核酸(fsDNA,ctDNA)分子作用后共振光光散射增强 ,其强度增加值与DNA的浓度呈线性关系 ,据此 ,建立了一种测定DNA的共振光散射法。该方法线性范围分别为0.02～6.0mg·L -1,0.04～7.0mg·L -1,相关系数分别为0.9984、0.9987 ,检出限分别为18.3、21.8μg·L-1,用于DNA合成样品的测定获得了满意的结果。同时 ,对该反应机理进行了探讨 ,并用紫外 -可见光谱求出了其形成常数     

碱性二苯基萘基甲烷染料褪色光度法测定透明质酸钠

在弱酸性介质中 ,碱性二苯基萘基甲烷染料与透明质酸钠作用形成结合产物时将导致溶液光吸收发生变化 ,在 5 85～ 6 1 6nm附近褪色且吸光度差 (ΔA)值与透明质酸钠浓度成正比 ,在 0 .1～ 2 .5mg/L(维多利亚蓝B)、0 .5～ 2 .0mg/L(夜蓝 )和 0 .1～ 0 .6mg/L(维多利亚蓝 4R)范围内符合Beer定律 ,表观摩尔吸光系数达 1 .5 1× 1 0 8～ 5 .5 2× 1 0 8L·mol-1 ·cm-1 (透明质酸钠的分子量以 5× 1 0 5计 ) ,其中 ,维多利亚蓝 4R灵敏度最高。据此 ,建立了一种新的测定透明质酸钠的分光光度法。该法简便、快速 ,灵敏度高 ,选择性好。应用于润舒氯霉素滴眼液、润洁滴眼露和施沛特注射液中透明质酸钠的测定 ,结果满意     

An Integrated Study on the Fading Mechanism of Malachite Green Industrial Dye for the Marquisette Curtain in the Studio of Cleansing Fragrance,the Palace Museum (Beijing)

Historical marquisette curtains were composed of lightweight fabrics, woven in an open-mesh and leno-type weave, usually made of silk, and found in Qing imperial buildings. As panel curtains, they were exposed to light, and so underwent fading. This study investigated the manufacturing technology and fading mechanism of dyed marquisette fabric from the Studio of Cleansing Fragrance, the Palace Museum (Beijing). The technological aspects were identified. The types of weave, fiber, and adhesive used to fix the curtain to the wooden frame were identified through microscopic observation and infrared spectroscopy. A color change characterization was performed based on UV-visible diffuse reflectance spectra. The textile colorant was identified as malachite green (MG), and its degradation by light was subsequently studied by dynamic photolysis experiments in a kinetic solution for the rapid exploration of by-products. The main degradation pathways were thus identified and the factors responsible for the induced color changes were discussed. A comparison of the liquid chromatography-mass spectrometry (LC–MS) results of the products derived from the photolysis method as well as of the samples extracted from the object allowed for the identification of the presence of different degradation pathways in the faded and unfaded parts of the textile. A metabolomics analysis was applied to account for the differences in the degradation pathways.     

355 nm光照下大气液相中HNO2与C6H5Cl的反应机理

利用瞬态吸收光谱技术进行了有氧、无氧条件下氯苯与亚硝酸水溶液的交叉反应机理研究，初步考察了这些瞬态物种的生长与衰减等行为, 并对其光解产物进行了GC/MS分析.研究表明，HNO₂在355 nm紫外光的照射下可产生•OH自由基, •OH和氯苯反应生成C₆H₅Cl•••OH，反应速率常数为（6.6～7.0）×10⁹ L•mol^-1•s^-1; 在有氧条件下C₆H₅Cl•••OH可氧化为C₆H₅Cl•••OHO2, 反应速率常数为(1.6 ± 0.2)×109 L•mol^-1•s^-1,然后进一步分解; C₆H₅Cl•••OH衰减或与亚硝酸等作用可形成多种含硝基的化合物或醌类物质.     

Factors Affecting Synthetic Dye Adsorption; Desorption Studies: A Review of Results from the Last Five Years (2017–2021)

The primary, most obvious parameter indicating water quality is the color of the water. Not only can it be aesthetically disturbing, but it can also be an indicator of contamination. Clean, high-quality water is a valuable, essential asset. Of the available technologies for removing dyes, adsorption is the most used method due to its ease of use, cost-effectiveness, and high efficiency. The adsorption process is influenced by several parameters, which are the basis of all laboratories researching the optimum conditions. The main objective of this review is to provide up-to-date information on the most studied influencing factors. The effects of initial dye concentration, pH, adsorbent dosage, particle size and temperature are illustrated through examples from the last five years (2017–2021) of research. Moreover, general trends are drawn based on these findings. The removal time ranged from 5 min to 36 h (E = 100% was achieved within 5–60 min). In addition, nearly 80% efficiency can be achieved with just 0.05 g of adsorbent. It is important to reduce adsorbent particle size (with Φ decrease E = 8–99%). Among the dyes analyzed in this paper, Methylene Blue, Congo Red, Malachite Green, Crystal Violet were the most frequently studied. Our conclusions are based on previously published literature.     

Triplication of the Photocurrent in Dye Solar Cells by Increasing the Elongation of the π‐conjugation in Zn‐Porphyrin Sensitizers

Porphyrins are promising sensitizers for dye solar cells (DSCs) but narrow absorption bands at 400–450 and 500–650 nm limit their light‐harvesting properties. Increasing elongation of the π‐conjugation and loss of symmetry causes broadening and a red‐shift of the absorption bands, which considerably improves the performance of the DSC. Herein we use an oligothienylenevinylene to bridge a Zn‐porphyrin system and the anchoring group of the sensitizer. We separately study the performance of the two basic units: oligothienylenevinylene and Zn‐porphyrin. The combined system provides a three‐fold enhancement of the photocurrent with respect to parent dyes. This is caused by an additional strong absorption in the region 400–650 nm that leads to flat IPCE of 60 %. Theoretical calculations support that the addition of the oligothienylenevinylene unit as a linking bridge creates a charge transfer band that transforms a Zn‐porphyrin dye into a push–pull type system with highly efficient charge injection properties.     

DNA Photocleavage by a Cationic BODIPY Dye through Both Singlet Oxygen and Hydroxyl Radical: New Insight into the Photodynamic Mechanism of BODIPYs

Two new NIR‐absorbing BODIPY dyes, each bearing two pyridinium groups, are synthesized and their DNA‐binding affinities and DNA photocleavage abilities examined in depth. While one BODIPY dye photocleaves DNA mainly through singlet oxygen, the other photocleaves DNA through both singlet oxygen and hydroxyl radical. To the best of our knowledge, this is the first example of a hydroxyl radical being involved in the photodynamic behavior of BODIPY‐type dyes. EPR experiments confirm the ability of these and several related BODIPYs to generate superoxide anion radical and hydroxyl radical. This finding may shed light on the mechanism of BODIPY‐based photodynamic therapy (PDT) and open a new avenue for development of more efficient BODIPY‐type PDT agents.     

266 nm光照下水溶液中氯苯与H2O2的反应机理研究

利用瞬态吸收光谱技术研究了不同条件下C₆H₅Cl与H₂O₂水溶液的激光闪光光解情况, 初步考察了其瞬态物种的生长和衰减等行为. 研究表明, •OH自由基和C₆H₅Cl反应生成C₆H₅Cl-OH adduct, 其反应速率常数在近中性、酸性条件下约为(5.89±0.65)×10⁹和(7.07±0.61)×10⁹ L•mol^－1•s^－1; 其衰减则符合双分子二级反应, 速率常数2k/εl＝1.1×10⁶ s^－1, 而在碱性时则为(4.34±0.51)×10⁹ L•mol^－1•s^－1, 衰减呈准一级反应, 速率常数为2.11×10⁵ s^－1. 在有氧条件下, O₂与C₆H₅Cl-OH adduct反应生成C₆H₅Cl-OHO₂ adduct, 其反应速率常数为6.8×10⁸ L•mol^－1•s^－1.