共查询到20条相似文献,搜索用时 15 毫秒
1.
Yu. A. Gorokh N. A. Aksenova A. B. Solov’eva V. A. Ol’shevskaya A. V. Zaitsev M. A. Lagutina V. N. Luzgina A. F. Mironov V. N. Kalinin 《Russian Journal of Physical Chemistry A, Focus on Chemistry》2011,85(5):871-875
The influence of amphiphilic polymers polyvinylpyrrolidone, poly(ethylene oxide), poly(vinyl alcohol), and pluronic F127 (propylene
oxide-ethylene oxide triblock copolymer) on the catalytic activity of a number of water-soluble metal-free porphyrin photosensitizers
was studied in the reaction of tryptophan photooxidation in aqueous solution. The introduction of the specified polymers was
found to enhance the activity of carbon-substituted tetrafluorophenylporpyrin, photoditazine, and dimegin. It was ascertained
that introduction of polyvinylpyrrolidone had the strongest effect on the increase in the photooxidation process rate; the
change in the activity of porphyrins was 30–70%. The introduction of poly(ethylene oxide), poly(vinyl alcohol), and pluronic
F127 was shown to enhance the rate of the process by 10–40%. It was concluded that this polymer effect was connected with
the dissociation of aggregates, in which form porphyrin molecules were present in aqueous solutions, as indicated by an increase
in fluorescence intensity of porphyrins. The introduction of polymers resulted in a bathochromic shift of the fluorescence
bands for all porphyrins, which accounted for the formation of complexes of porphyrin sensitizers with the polymers. 相似文献
2.
Glagolev N. N. Rogovina S. Z. Soloveva A. B. Aksenova N. A. Kotova S. L. 《Russian Journal of Physical Chemistry A, Focus on Chemistry》2006,80(1):S72-S76
It was demonstrated that the activity of tetrapyrrole photosensitizers (TPSs) of singlet oxygen generation (dimegin, tetrasulfophenylporphyrin, and photoditasine) in the oxidation of tryptophan in the aqueous phase decreases in the presence of polymers containing free amino groups (chitosan and polyallylamine). The decrease of the activity is accompanied by the change of the electronic absorption spectra of the TPSs. Analogues of chitosan with screened amino groups (chitosan sulfate and carboxymethylchitin) or without amino groups (carboxymethylcellulose), as well as hexamethylenediamine, a low-molecular-weight compound, do not affect the activity of the TPSs. The regularities observed can be accounted for by the association of molecules of the tetrapyrroles initiated by the complexation of the TPSs having external salt groupings with free amino groups of the polymers. 相似文献
3.
4.
T. M. Zhientaev N. S. Melik-Nubarov E. A. Litmanovich N. A. Aksenova N. N. Glagolev A. B. Solov’eva 《Polymer Science Series A》2009,51(5):502-511
Solubilization of hydrophilic porphyrins, 2,7,12,18-tetramethyl-3,8-di(1-methoxyethyl)-13,17-di(2-oxycarbonylethyl) porphyrin disodium salt (dimegin) and N-methyl-di-D-glucose amine salt of chlorine e 6 (photoditazine), as well water-insoluble meso-tetraphenylorphyrin in the micelles of Pluronics (triblock copolymers and propylene oxide and ethylene oxide), increases the photocatalytic activity of porphyrins in the course of the oxidation of L-tryptophan in aqueous salt-containing solutions. The maximum photocatalytic activity is attained for the photocatalysts based on the Pluronics P85 and F127 containing 50–70% ethylene oxide units. As a result of solubilization, the activity of tetraphenylporphyrin increases by a factor of 50, while the activities of hydrophilic dimegin and photoditazine increase by factors of 1.5 and 6, respectively. The increased activity of tetraphenylporphyrin is due to the dissolution and dissociation of aggregates in the presence of Pluronics. The increased activity of dimegin, which is known to aggregate in water, is primarily provided by disaggregation. In the case of photoditazine, which does not form aggregates in aqueous solutions and is likely to be localized in the polar micellar “crown,” the effect of a polymer is due to the local concentration of both a substrate and a catalyst in the micellar pseudophase. 相似文献
5.
The photocatalytic properties of some cyanogen-and thiocyanogen-based inorganic polymers, such as paracyanogens containing different metals (Hg, Ag, Cu), polythiocyanogens of different iodine contents, polycyanogen and poly (cyanogenthiocyanate), have been tested in two systems. Cu-containing paracyanogen and the iodine-poor polythiocyanogens catalyze the photoreduction of methylviologen under visible light, furthermore the Cu-containing paracyanogen catalyzes the photoreduction of water to hydrogen under UV irradiation.
, , , , (Hg, Ag, Cu), , (), . , , , , , , -.相似文献
6.
Vesicles of different morphologies were found to form in aqueous solutions of the surfactant sodium bis(2-ethylhexyl)sulfosuccinate, AOT, and in binary mixtures composed of AOT with poly(ethylene glycol) and poly(sodium 4-styrenesulfonate). Using electrical conductivity and fluorescence probing, two critical vesicle concentrations, cvc and cac, were determined. These critical aggregation concentrations correspond to different kinds of aggregates, which are easily observed by optical microscopy. 相似文献
7.
Theoretical and Experimental Chemistry - 相似文献
8.
The excited-state properties of heterodimers oftetra(4-carboxyphenyl)porphyrin (TPPC) and tetra(N-methylpyridyl) porphyrin (TMPyP) are studied by absorption and emission spectroscopy, EPR and zero-field ODMR. The excited singlet and triplet states of dimers formed by pairing H2TPPC with H2TMPyP or ZnTMPyP are localized on H2TPPC. The dimers formed by pairing H2TPPC with CuTMPyP and H2TMPyP with ZnTPPC or CuTPPC are non-fluorescent due to intramolecular electron transfer. 相似文献
9.
Porphyrin nanotubes represent a new class of nanostructures for which the molecular building blocks can be altered to control their structural and functional properties. Nanotubes containing tin(IV) porphyrins are photocatalytically active and can reduce metal ions from aqueous solution. The metal is deposited selectively onto tube surfaces, producing novel composite nanostructures that have potential applications as nanodevices. Two examples presented here are nanotubes with a continuous gold wire in the core and a gold ball at the end and nanotubes coated with platinum nanoparticles mainly on their outer surfaces. The latter are capable of photocatalytic reduction of water to hydrogen. 相似文献
10.
Study on the interaction of new water-soluble porphyrin with DNA 总被引:1,自引:0,他引:1
Kang J Wu H Lu X Wang Y Zhou L 《Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy》2005,61(9):2041-2047
A porphyrin meso-tetrakis{[4-(1-pyridyl)propoxy]phenyl}porphyrin (TPyPP) and its Ni complex (TPyPP(Ni)) have been synthesized and characterized by 1H NMR, UV-vis spectra. The interaction of two porphyrins with calf thymus-DNA (CT-DNA) has been explored by UV-vis, fluorescence and circular dichroic spectroscopy and viscosity measurements. The results suggest that these porphyrins can bind to DNA by the same binding mode. TPyPP outside binds by self-stack with DNA both at low drug load r (=[porphyrin]/[DNA]) and high drug load. Though TPyPP(Ni) has center metal nickel, binding mode with DNA has little difference compared with TPyPP, dominating out-binding mode with different direction along DNA. The binding constants of the TPyPP and TPyPP(Ni) to DNA were 4.65 x 10(5) M(-1) and 3.2 x 10(5) M(-1), respectively. A colored precipitate was found after time in two porphyrin's viscosity measurement. The reasonable interpretation is the porphyrins with alkyl connected N-position of pyridine can strongly interact with the anionic phosphates of DNA and lead to hydrophobic complex. 相似文献
11.
Dabrowski JM Pereira MM Arnaut LG Monteiro CJ Peixoto AF Karocki A Urbańska K Stochel G 《Photochemistry and photobiology》2007,83(4):897-903
A water-soluble halogenated porphyrin, namely 5,10,15,20-tetrakis(2-chloro-3-sulfophenyl)porphyrin (TCPPSO(3)H), was prepared and evaluated as sensitizer for photodynamic therapy (PDT). Photophysical properties of TCPPSO(3)H, such as high photostability, long triplet lifetime and high singlet oxygen quantum yield suggest high effectiveness of this class of halogenated porphyrins in PDT. TCPPSO(3)H is non-toxic in the dark and causes a significant photodynamic effect examined against MCF7 (human breast carcinoma), SKMEL 188 (human melanoma) and S91(mouse melanoma) cell lines upon red light irradiation (cutoff < 600 nm) at low light doses. Time-dependent cellular uptake of TCPPSO(3)H reached plateau at 120 min and was the highest for S91, 20% lower for MCF7 and 70% lower for SKMEL 188. Our results show that this halogenated water-soluble porphyrin is an efficient photosensitizer and reveal the potential of this class of compounds as PDT agents. 相似文献
12.
Teiji Tsuruta 《Macromolecular Symposia》1987,12(1):323-331
The present paper is concerned with studies for elucidation of the relationship between the structure of HA copolymers and their adsorption property toward lymphocyte subpopulations, B cell and T cell. HA is a polyamine graft copolymer of poly(hydroxyethyl methacrylate) as the backbone. In the earlier part of this paper, discussion will be made on our synthetic approach to HA copolymers having polyamine graft chains of controlled length and number, while, in the later part, the outline of our recent studies of biomedical behavior of HA copolymers in terms of selective adsorption of B cell against T cell will be presented. A possible mechanism for the cell separation will also be discussed. 相似文献
13.
Kai Wang Zhi Zhang Qianni Guo Xiaoping Bao Zaoying Li 《Frontiers of Chemistry in China》2008,3(4):406-412
A water-soluble porphyrin dimer (Por Dimer) containing eight positive charges, bridged by 4,4′-dicarboxy-2,2′-bipyridine,
has been synthesized. With Meso-tetrakis(N-methyl-pyridium-4-yl)porphyrin (H2TMPyP) as the reference compound, the water-soluble porphyrin dimer was investigated for its interaction with DNA by absorption,
fluorescence, and circular dichroism (CD) spectroscopy. The apparent affinity binding constant (K
app = 1.2 × 106) of Por Dimer binding to CT DNA was measured by a competition method with ethidium bromide (EB) (that of H2TMPyP was 6.9 × 106). The cleavage ability of Por Dimer to pBR322 plasmid DNA was studied by gel electrophoresis. The results suggest that the
binding modes of Por Dimer were complex and involve both intercalation and outside binding.
__________
Translated from Acta Chimica Sinica, 2007, 65(22): 2597–2603 相似文献
14.
Novel water-soluble polymeric photosensitizers (SPO) based on starch and containing porphyrin chromophores were synthesized and studied. The polymers were soluble in water and in dimethyl sulfoxide. Photophysical studies and solubilization of molecular probes proved the formation of hydrophobic, rigid microdomains in an aqueous solution of SPO; they were created due to the clustering of porphyrin chromophores attached to the polymer chain. SPO polymers absorbed light from the UV-visible spectral region. The polymers could sensitize photochemical reactions mediated by electron transfer, energy transfer or both, from the singlet-excited state of porphyrin chromophores to the molecules of organic compounds solubilized in the hydrophobic microdomains or residing in the water phase. 相似文献
15.
Krisztina Rácz Maria Burger István Lagzi Zsuzsanna Ungvarai-Nagy 《Reaction Kinetics and Catalysis Letters》2008,95(1):135-142
The water-soluble iron(III) complex of meso-tetra(4-sulfonatophenyl)porphine is oxidized by bromate in nearly neutral aqueous
solutions in an overall six-electron three-step consecutive reaction. Kinetics and mechanism of the reaction are described. 相似文献
16.
Koji Abe Hidehiko Sakamoto Yoshihiro Itoh Saburo Senoh 《Journal of polymer science. Part A, Polymer chemistry》1986,24(12):3433-3446
The efficiencies of polyelectrolytes, i.e., polycations and polyanions, and several kinds of water-soluble polymers as fusogens on soybean phospholipid liposome (SL) and egg yolk phospholipid liposome (EL) were investigated by the fluorescence quenching method. There were optimal concentrations for the induction of fusion in every system. Polycations induced fusion of liposomes at very low concentration in comparison with other polymers. Poly(carboxylic acid)s induced fusion at relatively high concentration. A strong acidic polyanion with high molecular weight also induced fusion of liposomes. The induction efficiency of poly(ethylene glycol) on fusion was higher than other nonionic polymers. The efficiency of fusion of EL was lower than that of SL in all systems because of the higher stability of EL membrane. It was found that electrostatic interactions, hydrogen bonding and/or hydrophobic interaction between these water-soluble polymers and liposomal membranes played an important role on aggregation and fusion of liposomes. 相似文献
17.
The reaction of iron(III) (meso-tetrakis(N-methylpyridinium-4-yl)porphyrin (Fe(III)TMPyP) with nitric oxide (NO) was studied by electronic absorption spectroscopy, ESR, and electrochemical and spectroelectrochemical techniques in aqueous solutions with pH from 2.2 to 12.0. Fe(III)TMPyP has been found to undergo a reductive nitrosylation in all pHs, and the product of nitric oxide binding to the porphyrin has been determined as iron(II) porphyrin nitrosyl complex ([Fe(II)(NO)TMPyP]). The rate of the reductive nitrosylation exhibits a tendency to get faster with increase in pH. An intermediate species was observed around neutral pH by spectroelectrochemical technique and was proposed to be the iron(II) nitrosyl complex of the mu-oxo dimeric form of FeTMPyP, which is known to be a predominant in neutral solutions. 相似文献
18.
《Electrochemistry communications》1999,1(7):274-277
An anodic voltammetric wave of NO catalyzed by meso-tetra(N-methyl-4-pyridyl) iron(III) pentachloride ([FeIII(TMPyP)]5+) was found in a phosphate buffer solution (pH 7.4). The current was 10 times larger than the diffusion-controlled current of NO without the iron porphyrin. The current can be used to detect NO in aerobic physiological environments. Spectroelectrochemical measurements suggested the formation of iron-nitrosyl complex, which is responsible for the catalytic oxidation of NO. The intermediate of the catalytic oxidation was detected by spectroelectrochemistry. 相似文献
19.
Yu Wu Hua Liu Jia-Cheng Liu Ren-Zhi Li Neng-Zhi Jin 《Journal of Coordination Chemistry》2019,72(1):69-82
Two new self-assemblies based on zinc porphyrin dyes ZnPx-ZnPA (x?=?1, 2) were synthesized and used for dye-sensitized solar cells. Capping layer dyes consist of zinc porphyrin (ZnP) as core unit and carbazole (P1), phenothiazine (P2) as electron-donating group. The dye ZnPA contains carboxylic group as an anchor porphyrin with upper dyes (denoted as ZnP1 and ZnP2) formed dyads by coordination bonds of Zn-to-ligand self-assembled devices. The assembly modes were also verified by transmission electron microscopy (TEM). The influence of the upper porphyrins on molecular structure as well as photovoltaic performance was investigated via photophysical and electrochemical studies and calculations. With addition of the phenothiazine unit, the ZnP2-ZnPA possesses better light-harvesting capability with a significantly red-shifted Q-band. The photoelectrochemical efficiencies for ZnP2-ZnPA are better than those of ZnP1-ZnPA ascribed to larger Jsc and Voc.
20.
Qiu WG Li ZF Bai GM Meng SN Dai HX He H 《Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy》2007,68(5):1164-1169
The interaction of a cationic water-soluble porphyrin, 5,10,15,20-tetrakis [4-(3-pyridiniumpropoxy)phenyl]porphyrin tetrakisbromide (TPPOC3Py), with anionic surfactant, sodium dodecyl sulfate (SDS), in aqueous solution has been studied by means of UV-vis, (1)H NMR, fluorescence, circular dichroism (CD) spectra and dynamic laser light scattering (DLLS), and it reveals that TPPOC3Py forms porphyrin-surfactant complexes (aggregates), including ordered structures J- and H-aggregates, induced by association with surfactant monomers below the SDS critical micelle concentration (cmc), and forms micellized monomer upon the cmc, respectively. The position of TPPOC3Py in the micelle is determined, which is not in the micelle core instead of intercalated among the SDS chains, most likely with the pyridinium group extending into the polar headgroup region of the micelle. 相似文献