近红外吸收菁染料光氧化反应机理的研究

本文选择了三种分子结构相同而母核杂原子不同的近红外吸收菁染料,对它们的光谱性能特征及光氧化稳定性能进行了研究。结果表明,具有三种不同母核杂原子的菁染料,其光氧化稳定性顺序为:苯并 唑>苯并噻唑>苯并硒唑。通过猝灭实验给出,在三种菁染料的光氧化反应机制中,具有反应活性的单线态氧和超氧负离子同时存在,其中单线态氧是导致菁染料褪色的主要因素。     

pH DEPENDENCE OF SENSITIZED PHOTOOXIDATION IN MICELLAR ANIONIC AND CATIONIC SURFACTANTS, USING THIAZINES DYES

Abstract— Our study of the kinetics of sensitized photooxidation, as a function of pH in anionic micellar systems using cationic dyes as sensitizers, shows that adsorption of the dye slows the protonation step of his triplet state. This observation has important implicaticins in interpretation of results in the so-called photodynamic effect in biological systems: using cationic dyes as sensitizers the rate of photooxidation for the same pH is different depending whether or not the medium allows adsorption of the dye.     

近红外吸收菁染料分子链结构对其光氧化稳定性能的影响

本文对具有不同分子链结构及不同链长,而母核结构分别为吲哚类及喹啉类的六种菁染料在溶液中的光氧化稳定性能进行了研究。结果表明菁染料的光褪色主要是由光氧化反应所致,当在分子链上引入不饱和环体结构时,可以使菁染料分子的光稳定性能增加;而随着分子链长的增加菁染料的光氧化稳定性能则明显下降。通过顺磁共振谱测定结果表明,在菁染料的自敏光氧化反应原初过程中,既存在单重态氧过程又存在超氧负离子过程。     

溴化银晶体光谱敏化光电流的研究和染料增感性能的判据

本文以AgBr晶体和菁染料为对象,对AgBr晶体的光电流进行了研究。实验发现,AgBr晶体经其本征吸收波长的光辐照后,可产生新的诱导吸收带。用诱导吸收带波长范围内的光辐照AgBr晶体,在非本征吸收区可测量到自敏化光电流。若染料吸附在AgBr晶体片上,则其敏化光电流将叠加在自敏化光电流上。增感染料对AgBr晶体的阳极和阴极光电导均有不同程度的敏化作用。本文在实验研究的基础上,提出了对染料增(减)感性能的判据S_D,比现有的一些判据更具有综合性。利用S_D—λ曲线可以较直观地对染料的增(减)感性能做出预测。本文利用S_D判据对一些实用增感染料及其组合作了分析。     

菁染料和份菁染料的合成及其溶液的光稳定性研究

利用UV-Vis吸收光谱仪和光化学反应器,研究了菁染料和份菁染料的光降解动力学.研究结果表明,染料在乙腈溶液中的光褪色反应遵循假一级或零级动力学衰减.与相应的份菁染料相比,携带正电荷的菁染料具有相对较好的光稳定性.     

菁染料和份菁染料薄膜的光稳定性研究

利用UV-Vis吸收光谱仪和光化学反应器研究了菁染料和份菁染料薄膜的光降解动力学.与相应的份菁染料相比,携带正电荷的菁染料薄膜具有相对较好的光稳定性.运用量子化学中的SCF-MO-PM3方法,全优化计算了这些染料的分子几何构型和电子结构,并解释了染料的光稳定性与其分子结构的关系.     

四甲川苯乙烯萘并噻唑半菁染料的合成

以2-甲基-3-磺酸丙烷-β-萘并噻唑等与肉桂醛及其衍生物为原料,合成了三种新型水溶性苯乙烯半菁染料,并对三种染料的紫外吸收进行了研究.     

HYPOCRELLIN-A SENSITIZED PHOTOOXIDATION OF BILIRUBIN

Hypocrellin A (HA) extracted from Hypocrellia bambusae (b.et Br.) sace, a derivative of 3,10-dihydroxy-4,9-perylenequinone, is a highly effective photosensitizer. Kinetic studies of the HA-sensitized photooxidation of bilirubin IX alpha (BR) in different solvents in the presence of various active oxygen quenchers indicate that in aprotic solvents the photooxidation goes via a Type II (1O2) mechanism, whereas in alkaline protic solvents Type I (electron transfer from an excited state of HA to the ground state of oxygen or the BR substrate). Type II and probably free radical reactions may occur simultaneously.     

菁染料和份菁染料溶液的光降解机理的研究

利用UV-Vis吸收光谱仪和光化学反应器,研究了菁染料和份菁染料溶液的光降解动力学,认为染料在乙腈溶液中的光褪色反应服从假一级或零级动力学.利用GC/MS光谱仪检测了染料的光降解产物.与相应的份菁染料相比,携带正电荷的菁染料具有相对较好的光稳定性.研究结果表明,菁染料光降解反应的中间体可能是染料的半氧化态Dye⁺,并利用纳秒级闪光光解技术研究了Dye⁺的瞬态吸收光谱.     

SENSITIZED PHOTOOXIDATION OF WOOL BY FLUORESCENT WHITENING AGENTS. A DIRECT SPECTRAL STUDY

Abstract—A fluorescence spectral study has been made of the photochemical behaviour of two types of fluorescent whitening agents, a naphthotriazolylstilbene and a bistriazinylaminostilbene, in single fibres of wool. The photodecomposition of each molecule of the naphthotriazolylstilbene is accompanied initially by the photooxidation of up to 7 residues of trp in the fibre. Amino acid analyses show that his and met residues are also photooxidized. Inhibition of the photooxidation of these amino acids by sodium azide suggests that singlet oxygen is involved in the reaction.     

新型吡喃鎓方酸菁染料溶剂效应、聚集行为研究

本文研究了五个吡喃鎓方酸菁染料的溶剂效应,发现最大吸收峰波数υ与函数f(n,ε)存在较好的线性关系,而Bayliss函数项(n²-1)/(2n²+1)决定了吸收光谱的位移变化Δυ,同时还分析了氢键相互作用对理论函数模型的误差.根据染料的聚集动力学证实了染料在正丙醇/水(4:21,体积比)体系中确有二聚体的产生,并发现了两组不同的聚集特性.此外,使用APCIMS质谱技术证实Dye3二氯甲烷浓溶液中也产生了二聚体.     

SENSITIZED PHOTOOXIDATION OF ISOEUGENOL TO VANILLIN

Abstract— The photochemical conversion of isoeugenol to vanillin can proceed via the ¹O₂ (¹Δ_g) state of oxygen and can be effected over a wide range of base and dye concentrations. A typical situation involving methylene blue (0.3 mM), isoeugenol (24 mM) and a base concentration of 0.1 N will give yields of approximately 35% of the theoretical amount.     

含N-烷基吲哚环方酸菁染料的合成及性能

本文合成了七个N-烷基取代吲哚环的方酸菁染料,通过红外光谱、核磁共振氢谱、质谱与元素分析确认其结构。测定它们的电子吸收光谱、熔点、溶解度和光褪色。结果表明共轭链上引入方酸桥环提高了光稳定性,N-烷基对染料的λmax的影响很小,但较大地改进了溶解度与熔点,带有支链的烷基有更好的溶解性能。     

菁染料与溴化银相互作用性质的研究

本文用计时电位法及电位滴定研究了十六种不同染料与溴化银之间的相互作用,进一步证明了具有离域π-电子的菁染料才能与卤化银形成络合物的论点。从得到的平衡常数K表明,固体表面上的卤化银-染料与溶液中银离子-染料具有相同键性质,都是银离子与染料离域π-电子作用的结果。     

PHOTOOXIDATION OF HORSE AND SPERM-WHALE MYOGLOBIN SENSITIZED BY THE HEME GROUP

Abstract —The irradiation of horse and sperm-whale Fe 3 * or Fe 2* myoglobins with visible light showed that axial ligands that render the heme diamagnetic (e.g. O₂, CO or CN^-) endow the hemoproteins with a marked photosensitivity. In contrast, high-spin myoglobins are unaffected by visible light. These findings appear to be of general validity for all hemo-proteins and are in agreement with the involvment of the triplet state of the heme as the reactive intermediate. In all cases, the overall photoprocess occurs within a very narrow spatial range, leading to specific modification of these photooxidizable side chains adjacent to the chromophore. Therefore, this technique can be used to probe the environment of the prosthetic group in hemoproteins. In particular, our data suggest that, in horse myoglobin, histidines-93 and -64 represent the heme-linked and the distal imidazole groups, respectively; moreover, the thioether function of methionine-131 must be nearer the heme in horse than in sperm-whale myoglobin. The selectivity of the photoreaction can be further enhanced by a suitable choice of the sixth ligand, and/or by controlling the pH of the irradiated solution. For example, for both proteins, irradiation of the cyanide derivative results in specific photooxidation of the proximal histidine, whereas irradiation of horse CO-ferromyoglobin at pH values below 6 causes specific photooxidation of methionine-131. Consequently, this photooxidative procedure can also be utilized to monitor conformational changes upon binding of the heme with different ligands, as well as to achieve the selective modification of amino acid residues, which are usually buried inside the protein molecule.     

SENSITIZED PHOTOOXIDATION OF PINENES BY 9,10-DICYANOANTHRACENE

Abstract —The products of 9,10-dicyanoanthracene sensitized photooxidation of α- and β-pinene were separated and identified. The mechanism of this reaction was investigated by fluorescence spectroscopy, solvent dependence and determination of oxidation potentials of olefins. The formation of an exciplex between excited dicyanoanthracene and pinenes was observed in non-polar solvents. On the bases of these observations, an electron transfer mechanism is proposed for the initial step of this reaction.     

含吲哚核端基多甲川菁染料的合成及性能

我们曾合成了具有桥环的硫三碳菁及多甲川苯乙烯菁,并测定了光学性能。本文报道吲哚环为端基的桥链三碳菁和四甲川苯乙烯菁的合成及在有机溶剂中电子吸收光谱及溶解性能的测定。所用仪器同前,7种多甲川菁染料的合成反应如下:     

菁染料在荧光探针及光动力疗法中的应用

菁染料的研究及应用已有100多年的历史,近年来,它们在生物方面的应用研究已取得一定的成果.本文就近几年菁染料及其衍生物在生物医疗方面的研究及进展情况加以综述,特别阐述了这类染料用作荧光探针在生物大分子标识以及作为光敏剂在光动力疗法(PDT)中用于恶性肿瘤的诊断与治疗这两方面的研究进展.     

菁染料的溶剂效应

本文研究了不同系列的16种菁染料在极性不同的溶剂中的吸收光谱。发现染料分子吸收峰(M带)的溶剂化“红移”不仅与溶剂的折射率n有关,而且与溶剂的介电常数ε有关。其v=(λ_max)^-1(cm^-1)与溶剂的上述两种性质的函数f(n,ε)=n²-1/2n²+1 + α(ε-1/ε+2)成良好的线性关系。式中α为比例系数,其值一般小于1,符号取决于染料本身的溶剂化显色性。在混合双液体系中,有些染料可形成二聚体,其双分子吸收带(D带)的溶剂化“蓝移”——△v(cm^-1)亦与上述函数f(n,ε)成良好的线性关系。实验结果表明,染料二聚体与溶剂发生作用时,相当于一个新的光学单元。     

KINETIC FACTORS GOVERNING SENSITIZED PHOTOOXIDATION OF EXCITABLE CELL MEMBRANES

Abstract— The kinetic factors which determine the rate at which Na⁺ channels in nerve membranes become photochemically modified were studied on giant axons from lobsters using the double sucrose gap voltage clamp technique. Axons were bathed in artificial sea water containing sensitizing dyes and illuminated from a Xe are source with light in the visible region while being repetitively step depolarized. Successive values of peak Na⁺ current and time-to-peak were monitored and rate constants for their change served as the assay for magnitude of modification. Action spectra for four sensitizers in the fluorescein series exhibited red shifts of roughly 17nm demonstrating that sensitizing species are not simply free in solution. Eosin Y diffuses to its sensitization sites with a half time of 70s indicating the existence of a major diffusion barrier which may mean that dye must penetrate to the interior of the membrane to be effective. Eosin Y is removed from sensitization sites by rinse with the same half time but shows two fractions: a faster fraction comprising 80% of sensitizing effectiveness and a slower fraction comprising 20%. The concentration dependence for Eosin Y is linear below 10 μ M and shows a progressive saturation at higher values, where the relationship is difficult to determine because of shielding. Different sensitizers vary in their ability to sensitize block of channels vs disruption of inactivation, demonstrating separate processes for the two modifications. It is suggested that both modifications proceed from single photon absorption events by individual sensitizer molecules bound or located close to the modification sites on the channels.