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31.
Photovoltaic and spectral properties of tetraphenyloporphyrin and metallotetraphenyloporphyrin dyes 总被引:1,自引:0,他引:1
Spectroscopical properties and photocurrent (or photovoltage) of tetraphenyloporphyrins and metallotetraphenyloporphyrins in nematic liquid crystal have been studied. Photoelectric response has been measured in an electrochemical cell made of the semitransparent semiconducting and golden electrodes with porphyrin dyes embedded in liquid crystal. Fluorescence, time-resolved luminescence in microsecond time scale and photoacoustic spectra have also been measured. The competition between radiative, non-radiative processes and charge transfer is discussed. It has been shown that effectivity of porphyrins for photocurrent generation depends on the presence/absence of central metal in the macrocycle of porphyrin skeleton and the kind of metal. The schematic model of the contributions of the dye molecule and semiconducting electrode in the electron transfer process is shown. 相似文献
32.
Three acyclic polythioethers containing 2-thienyl units at both ends were synthesized and the effect of substituent on the extraction of copper(II) was studied. The methyl groups in the terminal thiophene ring have imparted an appreciable degree of increase in the percent extraction of copper(II), while the introduction of chlorine atoms into the 2-thienyl unit resulted in the reverse effect. Among the counter dye anions examined, tetrabromophenolphthalein ethylester was the best one for copper(II) extraction. The composition of extracted species was evaluated to be 122 (Cu(II)/polythioether/dye anion). Quantitative extraction of copper(I) was attained as complexes with various triphenylmethane dyes, i.e., bromocresol green, bromothymol blue, bromo-phenol blue and pyrogallol red. Copper(I) in organic phase was completely back-extracted with 2 mole/l sulfuric acid containing 10% hydrogen peroxide. 相似文献
33.
We report on the exciton dynamics in the J-aggregating dye 5,5, 6,6-tetrachloro-1,1-diethyl-3,3-di(4-sulfobutyl)-benzimidazolocarbocyanine which is known readily to form J-aggregates, even at room temperature and at a low concentration. We performed a series of time-correlated singlephoton-counting experiments at different emission wavelengths and at different temperatures in the range between 1.5 and 125 K. Additionally, the temperature dependence of the relative fluorescence quantum yield was determined. 相似文献
34.
35.
含吲哚核端基多甲川菁染料的合成及性能 总被引:6,自引:0,他引:6
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: 相似文献
36.
研究了4个偶氮染料在酸性介质中的电还原性质。偶氮基在酸性介质中的还原均为不可逆四电子一步全还原。邻、对位上有吸电子基(如—CO_2Bu-n)的偶氮基较间位有吸电子基时更易被还原。分子中同时含有偶氮基和硝基时,偶氮基先被还原。 相似文献
37.
P. Ramachandra T. Siva Rama Krishna Gautam R. Desiraju 《Journal of Chemical Sciences》1989,101(4):327-334
The compound 3-hydroxy-6-(4′-nitro)phenylazopyridine (1) was observed to incorporate several organic solvents of crystallisation, forming stable clathrates. These clathrates decompose
upon heating and the host material is chemically transformed. Single crystal X-ray diffraction studies on the ethanol clathrate
lead to a reasonable model for the host structure. But the guest molecules are severely disordered. Alternatively, the compound
forms twinned crystals. The chemically closely related compound2 does not form clathrates. 相似文献
38.
39.
M. Yakup Arca Meltem Ylmaz Emine Yaln Gülay Bayramo
lu 《Journal of membrane science》2004,240(1-2):167-178
Poly(hydroxyethyl methacrylate), pHEMA, and a composite pHEMA/chitosan networks were synthesized in the membrane form via UV initiated photo-polymerisation in the presence of an initiator ,′-azoisobutyronitrile. Reactive Yellow 2 (RY-2) was covalently immobilised as a dye–ligand onto both membranes. The polarity and surface energy of the investigated membranes were determined by contact angle measurement. The incorporation of chitosan in the pHEMA networks produced more hydrophilic surface, as indicated by contact angle analysis. The binding characteristics of lysozyme, γ-globulins, human serum albumin (HSA) and bovine serum albumin (BSA) to pHEMA-RY-2 and pHEMA/chitosan-RY-2 affinity membranes have been investigated from aqueous solution and their dye–ligand free forms were used as control systems. When chitosan was incorporated in the pHEMA network as a cationic polymer led to higher adsorption capacity for the lysozyme. Selective adsorption behaviour was also observed in the case of pHEMA/chitosan-RY-2 membrane for the lysozyme. The non-specific adsorptions of the lysozyme on the pHEMA and pHEMA/chitosan membranes were about 1.9 and 7.2 mg/ml, respectively. These were negligible for all others investigated proteins. The lysozyme adsorption data was analysed using the first-order and the second-order models. The first-order equation in both affinity membrane systems is the most appropriate equation to predict the adsorption capacities of the adsorbents. The adsorption isotherms well fitted the combined Langmuir–Freundlich model. A theoretical analysis has been conducted to estimate the thermodynamic contributions (changes in enthalpy, entropy and Gibbs free energy) for the adsorption of lysozyme to both dye–ligand immobilised membranes. The adsorption capacities of both dye–ligand immobilised membranes increased with increasing the temperature while decreased with increasing the NaCl concentration. Both affinity membranes are stable when subjected to sanitization with sodium hydroxide after repeated separation–elution cycles. 相似文献
40.
合成了E,E-1,4-二[2′,2″-(苯并(口恶)唑基乙烯基)]苯及衍生物共14种,测定了它们的熔点、红外光谱、核磁共振氢谱、紫外吸收光谱和荧光发射光谱、荧光量子产率及激光性能。 相似文献