荧光素衍生物在TiO_2胶体中的光物理性质研究

测定了以荧光素为光敏剂的电子给体-受体二元化合物荧光素蒽醌甲酯（FL- AQ）及模型化合物荧光素丁酯（FL4）在溶液中和在二氧化钛（TiO_2）胶体中的吸 收光谱、荧光光谱、荧光寿命等。发现荧光素蒽醌甲酯与荧光素丁酯均可通过酚羟 基较好地吸附在TiO_2胶体上。从吸收光谱可得,FL4与TiO_2形成表面络合物的表 观结合常数（K_(app)）大约为3590 mol~(-1)·L,结合率（α）为0.86;FL-AQ与 TiO_2形成表面络合物的K_(app)大约为3060 mol~(-1)·L,α为0.84。同时通过 ESR光谱讨论了光诱导电子注入机制。     

TC16PyP(4)/AnQ混合LB膜结构的研究

我们曾报道了沉积在 Sn O2 导电玻璃基片上的 5 ,1 0 ,1 5 ,2 0 -四 -(4 -十六烷基吡啶基 )卟啉 [TC16 Py P(4 ) ]LB膜的光电性质 [1] .结果表明 ,电解质溶液中含有电子给体和受体时 ,由于超敏化作用 ,样品光电效应明显增强 .在研究其它 LB膜时 ,我们发现将两亲性卟啉分子 A与等物质的量憎水性化合物 B一起拉膜时 ,有可能得到一一对应的混合 LB膜[2 ] .如果 A和 B分别为电子给体和受体 (反之亦然 ) ,A和 B之间应有较强的相互作用 .将这种混合 LB膜沉积在基板上 ,可能表现出新的电子与光学性质 ,从而得到具有多种功能的新材料 .本文…     

PHOTOCHEMISTRY OF HYPOCRELLIN A (Ⅳ)——HYPOCRELLIN A-SENSITIZED PHOTOOXIDATION OF DIPHENYLAMINE

The photooxidation of diphenylamine in acetonitrile and methanol using Hypocrellin A as sensitizerwill be reported in this paper. The products in the two solvents were isolated and identified. The reac-tion mechanisms were investigated. In acetonitrile, diphenylamine was oxidized by singlet oxygen to formN-phenyl-p-benzoquinonimine. In methanol, N-phenyl-p-benzoquinonimine was produced predominantlythrougth a mechanism irrelevant to singlet oxygen. A small amount of diphenylamine reacted with methanoland singlet oxygen to give a novel product: N-phenyl-2-methoxy-p-benzoquinonimine.     

8-甲氧基呋喃并[3′,2′∶6,7]香豆素与烯烃光环合加成反应的研究Ⅰ.

8-甲氧基呋喃并[3′,2′∶6,7]香豆素(8-MOP,1)与长波紫外线配合,对治疗银屑病有很好的疗效,曾引起医药、生物、化学界对其光治疗机理的广泛研究。Song等认为这与1和DNA中的碱基光环合加成反应有关,但反应究竟是经由1的激发三线态还是激发单线态至今尚未确证。本文报道1与环已烯(2)和庚烯-1(3)的光环合加成反应,并鉴定了它们的加成产物,发现加成发生在1的3,4位双键上。通过猝灭实验和动力学测定,表明反应是经由激发     

ESR方法检测竹红菌素的半醌负离子自由基

从顺磁共振波谱检测到通过竹红菌素的光诱导还原和基态竹红菌素跟脂肪胺的电子转移两条途径所得到的自由基信号, 并由电化学还原得到同一自由基, 确认它为半醌负离子自由基。竹红菌素溶液中加入芳香胺观察不到ESR信号。它的3,10位上与醌基相邻近的羟基离解以后, 无论在基态还是在激发态都观察不到ESR信号。此外, 还从吸收光谱观察到半醌负离子自由基吸收以及竹红菌素跟脂肪胺之间的相互作用。     

Intermolecular and intramolecular electron transfer from eosin ester to viologen

The covalently -(CH2)10- linked eosin-butylviologen compound has been synthesized. The photoinduced electron transfer of eosin ester and butylviologen as well as the influence of addition of cyclodextrin or amylose into the solution of linked compound on the system have been studied by the absorption spectra, fluorescence spectra and fluorescence lifetime. The results indicated that the intramolecular electron transfer is much more efficient than the intermolecular one. Due to the formation of inclusion complex, the process of intramolecular electron transfer was changed after adding cydodextrin or amylose.     

吸附在银溶胶表面的2种卟啉化合物的荧光分析

研究了银溶胶对2种卟啉化合物——5,10,15,20-四对羟基苯基卟啉(简称T(4-HP)P)和5-羟基苯基-10,15,20-三苯基卟啉(HPTPP)的荧光猝灭行为,在5.0×10~6mol/L的T(4-HP)P,HPTPP溶液中分别加入1.5×10~(-4)mol/L的银胶后,两者的荧光猝灭效率都达90%以上,通过荧光猝灭曲线求得这2种卟啉与银胶之间表观作用常数分别为3.16×10~4(mol/L)~(-1),2.79×10~4(mol/L)~(-1),文中还讨论了银胶对T(4-HP)P,HPTPP荧光猝灭过程的动力学及2种卟啉分子与银胶之间的作用机理.     

STUDY ON THE NANOSECOND TRANSIENT ABSORPTION SPECTRA OF HYPOCRELLIN A

In this paper, the nanosecond transient absorption spectra and the fluorescence spectraof Hypocrellin A(HA) are examined in solvents of varying polarity. There are three absorp-tion bands in dilute HA solutions: Ⅰa, Ⅱa are defined as the triplet-triplet absorption ofHA, the band Ⅲa is supposed to be the absorption of the solvent--sepatated ion pair (SSIP).In more concentrated solutions, only the absorption of SSIP was observed. The effects ofsolvent polarity on transient absorption spectra and fluorescence spectra of HA and the effectof oxygen on the intensities of the fluorescence of HA are discussed. Then a reasonablemechanism for the photolysis of HA is proposed.     

Photoinduced charge injection from excited triplet hypocrellin B into TiO_2 colloid in ethanol

Photosensitization of TiO2 colloid by hypocrellin B (HB),a natural photodynamic pigment with extremely high photosta-bility,has been studied by surface enhanced Raman spec-troscopy (SERS),laser flash photolysis and electron paramagnetic resonance (EPR) techniques.The photoseiisitization of TiO2 occurred practically from the excited triplet dye and the electron injection rate constant is 1.3×106 s-1.The influences of donor and acceptor on the electron injection were investigated.     

竹红菌素自敏光氧化反应机制的研究

本文对竹红菌素自敏光氧化反应的机制作了较详细的研究,竹红菌素通过自敏光氧化反应生成不稳定的过氧化物,它可以放出¹O₂回到母体化合物,也可以转化为稳定的氧化产物,我们用活泼的单重态氧的接受体捕获到了体系中放出的¹O₂,用吸收光谱的变化证明过氧化物回到了母体化合物。文中还用猝灭实验证实此自敏光氧化反应除涉及¹O₂机制外,还有其它机制起着作用。