IMAGING SCIENCE AND PHOTOCHEMISTRY

INTRAMOLECULAR CHARGE TRANSFER COMPOUND ——A STUDY ON THE SPECTRA AND THE PHOTOPHY-SICAL BEHAVIOR OF CHALCONE DERIVATIVES

WANG PENG-FEI, WU SHI-KANG

1993, 11(4): 289-294. DOI: 10.7517/j.issn.1674-0475.1993.04.289

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In this work, several chalcone derivatives which contained strong electron donor moiety and different groups with various electron withdrawing ability were synthesized.The spectra and photophysical properties of these compounds were also studied.Results showed that the luminescence behavior depended on not only the molecular structures, but also the polarity of media used and the enviroment temperature.Results obtained were discussed briefly.

STUDY ON THE PHOTOSENSITIZATION OF CARENE BY AROMATIC CYANIDE Ⅱ.THE PRODUCT DISTRIBUTION OF PHOTOSENSITIZED OXYGENATION OF CARENE AND ITS MECHANISM PROCESS

XIE JIE, WANG JIA-YU, WANG Duo-YUAN, HE HUI-ZHU

1993, 11(4): 295-301. DOI: 10.7517/j.issn.1674-0475.1993.04.295

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This paper reported that the product distribution of photosensitized oxygenation of carene by aromatic cyanide are related to solvent and sensitizers.The experimental results indicated that the products formed with rose bengal as sensitizer are typical " ene " type products and non- " ene " type product increase more than 30%, except " ene " type products in the presence of DCA as sensitizer.The investigation result shows that DCA sensitized photooxygation of carene include both electron and energy transfer process.

STUDY ON THE STRUCTURE (CONFORMATION) AND PROPERTIES OF COLLAGEN/GELATIN Ⅲ.THE CHARACTERIZATION OF 4 DIFFERENT CONFORMATIONS SEPARATED FROM COLLAGEN

JIN GUI-XIAN, PENG BI-XIAN

1993, 11(4): 302-306. DOI: 10.7517/j.issn.1674-0475.1993.04.302

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Chemical reagent of high purity α₁,α₂,β₁₁,β₁₂ and γ were collected and used as the standards.Their migration distances (d) in SDS-PAGE have been determined.Using the linear relationship between the logarithum of molecular weight log M_n and d, the 6 different fractions (a, b, c, d, e and f)have been separated from collagen, desalted, lyophilied and identified as α_1a,α_1b,β₁₁,β₁₂,α₂ and (α₁ +β₁₁) respectively.

THE MECHANISTIC STUDY OF HIGH CONSTRAST CAUSED BY INHIBITORS

CHEN SI-HAI, JI SU-XUE, REN XIN-MIN

1993, 11(4): 307-317. DOI: 10.7517/j.issn.1674-0475.1993.04.307

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The adsorption behavior of a series of inhibitors on silver and silver bromide were investigated by using UV spectrophotometry and electrochemical techniques.In association with the sensitometric results obtained on using developers containing different inhibitors, it is concluded that high contrast caused by inhibitors can be achieved when the inhibitor moderately adsorbs on the latent image, coupled with a weak adsorption on silver bromide.The mechanism of high contrast and the adsorption properties of inhibitors on silver were also discussed.

STUDY OF THE PHOTO-INDUCED ELECTRON TRANSFER AND PHOTOREACTION PROCESS OF BENZYL ALCOHOL ON THE SURFACE OF TiO₂ COLLOID

WANG HAI, CHEN DE-WEN, ZHANG TONG, Xu GUANG-ZHI

1993, 11(4): 318-324. DOI: 10.7517/j.issn.1674-0475.1993.04.318

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Spin trapping-ESR method was used to study the photo induced electron transfer process of benzyl alcohol on the surface of super fine particles of TiO₂.The results show that at different pH value, there are distinguishing differences about photochemical behaviors of benzyl alcohol on the colloid surface.At very low pH, signals of singlet oxygen were detected clearly.When pH value was about 3.0, super oxide anion dominated.When pH values were raised to 4-6,large amount of benzeloxyl radical was generated, especially when pH=6.When pH was about 7, besides benzeloxyl radical, some hydroxylethyl radical and benzyl radical occured.The photochemical mechanisms of photo-induced electron transfer process under different acidic conditions were discussed.

THE FULL ANALYSIS OF DIFFERENT CONFORMATIONS (α, β, γ) IN PHOTOGELATINS

CHEN LI-JUAN, WANG TONG, PENG BI-XIAN

1993, 11(4): 325-334. DOI: 10.7517/j.issn.1674-0475.1993.04.325

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A careful survey and investigation of the literature references indicate that up to now SDS-PAGE method can be used to characterize the < α, α₁, α₂, β conformations γ and >γ conformations failed to be realized by this method, it is really a serious fault in full analysis of different conformations of photogelatin and in judgement of the gelatin quality based on conformation components.In general how to handle the contradiction between the crosslinkage degree (hence the pore magnitude) and the physicomechanical property of polyacrylamide gel plate is acknowledged to be the key problem in realizing the full conformation analysis.In present study a series of factors such as the relative concentration of acrylamide and the N,N-methylene-bis acrylamide and the cross-linkage gradient formation were investigated as a function of the migration distance of all conformations.An emphasis was made to observe whether the γ and > γcomponents can enter the polyacrylamide gel plate together with the other conformation components.The experimental data demonstrated that the entire conformation components ranging from < α, α₁, α₂, β, γ and > γ, without exception, can be separated and characterized with satisfactory resolution by the SDS-PAGE method improved and developed in present study.This improvement and development are of important significance for gelatin routine analysis and controlling the process parameters so as to optimize the correctly relative content of different conformations for a specialized type of gelatin products.

A STUDY OF THE REDUCING POWER CHANGE OF PHOTOGELATINS IN DEPENDENCE ON THEIR EXTRACTION DEPTH

CHEN LI-JUAN, PENG BI-XIAN

1993, 11(4): 335-341. DOI: 10.7517/j.issn.1674-0475.1993.04.335

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A series of photogelatin samples extracted for different times was collected, The reducing power (RP) was determined by potential titration method, the Methionine, Metsox and Metson contents were evaluated with L-8500 amino acid analyzer, the molecular weight distribution of the different conformation components contained in different extracts (No.1-5) was found with SDS-PAGE method.It was shown that a maximum was found on the curve of RP versus extraction depth and a parallel relationship was demonstrated between RP and the α₁, α₁ + α₂ or α₁/α₂.This parallel relationship can be elucidated by the following 2 main points: (1) α₁ chain contains higher content of Met than that of α₂ chain, which can be clearly seen from their primary structure of amino acid sequence; (2) among the extracted gelatings (No.1-5)only the gelatin of the 2nd extract ranks the 1st containing the highest content of α₁ conformation component.The discovery and the elucidation of the parallel relationship between RP and extraction depth are of significance in the classification and specification of photogelatins and in making full and reasonable use of different gelatin-extracts in various specified circumstances.

A STUDY OF THE CHANGE OF CONFORMATION COMPONENTS OF PHOTOGELATIN IN DEPENDENCE UPON THE EXTRACTION PROCEDURES

CHEN LI-JUAN, PENG BI-XIAN

1993, 11(4): 342-348. DOI: 10.7517/j.issn.1674-0475.1993.04.342

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In present study an attempt was made to correlate the change (content) of different conformation components in photo-gelatin and the extraction sequences used in gelatin manufacture with the aid of the improved SDS-PAGE method.The quantitaive determination of the conformation showed that the peptide chain with molecular weight less than that of α can be separated into 5 smell fraction (5 peaks) characterized as α_p1-5.The MW of α_p5 is approximately more than 30000 which appeared in the 1st and 2nd extractions but disappeared in the 3rd and 4th ones.The MW of α_p increases steadily with the increase of extraction times.The change of the β conformation components with the increase of the extraction times has been found to be of no serious extent (except the 5.th final extraction).The ratio of α₁ to α₂(α₁/α₂) increases only a bit with the increase of extraction times, basically, with flucturation 1±0.1.This ratio value is quite different from that contained in collagen.The change of β conformation is similar to a contrary to β, the content of γ conformation with the increase of extraction times has shown to be a grossy proportional correlation.Present study also quantitatively characterized the component with MW more than that of γ, their MW has been found to be ranked within 0.4-0,8 million.

PHOTOINDUCED INTRAMOLECULAR ELECTRON TRANSFER IN TRIAD COMPOUND ZINC PHTHALOCYANINE-VIOLOGEN-FERROCENCE AND ITS PHOTOELECTRIC EFFECT

ZHOU QlNG-FU, LIU JI-XIANG, XU HUI-JUN, XU JIN-MEI, JIA JIAN-GUANG, XIAO XU-RUI

1993, 11(4): 349-355. DOI: 10.7517/j.issn.1674-0475.1993.04.349

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A novel amphiphilic triad compound was synthesized by linking viologen with zinc phthalocyanine and ferrocene by flexible chains.Absorption and fluorescence spectra as well as fluorescence lifetime have been determined.Time resolved transient absorption spectrum and time profile measurements show that photoinduced intramolecular electron transfer in the triad is more efficient than that in dyad, giving a final long-living charge-separated state with longer lifetime beyond 100 μs.A mechanism of two-step charge separation process was suggested.The thin films of the triad compound molecules in monolayer and multilayers were successfully deposited on SnO₂ substrate and photoelectric effect of the LB films were observed.

THE CROWN COMPOUNDS AS MODIFIERS FOR AgX EPITAXIAL GROWTH

LI XIAO-LING, ZHOU BEN-MAO

1993, 11(4): 356-360. DOI: 10.7517/j.issn.1674-0475.1993.04.356

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It was found that 1,7,10,16-tetraoxa-4,13-dithiacyclooctadecan (2S-1 8-C-6)and 1,7,10,16-tetraoxa-4,13-diazacyclooctadecan (2N-18-C-6)can act as modifiers when epitaxial deposition occurs to nonisomorphic silver salt, while 1,4,7,10,13,16-hexaoxacyclo-octadecan (18-C-6)can ont.They have no effect on the epitaxial growth of the isomorphic crystals.The aza-and thiacrown ethers can also etch the host grains, and their etching abilities decrease in the order of 2S-18-C-6, 2N-18-C-6and 18-C-6, they are the same as complexing abilities with Ag⁺.In fact,18-C-6 does not etch the octahedral AgBr emulsion.The modification of epitaxial deposition by the crown ether is related much to the comlexing between the crown ether and Ag⁺ and therefore, the solubilization of the crystal in the crown ether.

THE CROWN COMPOUNDS AS PHYSICAL RIPENERS FOR AgBr CRYSTAL GROWTH

LI XIAO-LING, ZHOU BEN-MAO

1993, 11(4): 361-365. DOI: 10.7517/j.issn.1674-0475.1993.04.361

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It was found that the AgBr grain size increased with the increasing concentration of l,7,10,16-tetraoxa-4,13-dithia-cyclooctadencan (2S-18-C-6) in the emulsion due to the latter’s complexation with Ag⁺, and subsequently the decrease of the supersaturation of the AgBr nucleation, and the photochemistry and dielectric loss of the prepared AgBr emulsion changed with the grain size in a regular pattern.The addition of the crown ether to the deionized bone-gelatin solution made small crystals dissolved, thus, well-distributed emulsion with high contrast could be got.Emulsion ripening was quite concerned with the heteroatoms in the crown ethers,2S -18 - C - 6 could act as a strong physical ripener while l,7,10,16-tetraoxa-4,13-diazacyclooctadecan (2N-18-C-6)and N-toluensulfonyl -7-aza-l,4,10,13-tetrathiacyclohexadecan (NTsTTH) could only act as the solvents of AgBr, and 1,4,7,10,13,16-hexaoxacyclooctadecan (18-C-6) has merely ripening effect on the emulsion.

AGGREGATION OF COPPER-PHTHALOCYANINES WITH DIFFERENT ALKOXY CHAINS IN ORGANIC SOLUTION

SHEN SHU-YIN, LIU KAI, ZHANG XIAN-FU, ZHOU QING-FU, XU HUI-JUN

1993, 11(4): 366-370. DOI: 10.7517/j.issn.1674-0475.1993.04.366

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The synthesis and aggregation of copper phthalocyanine having different alkoxy substi-tutents are described.In toluene-acetone solution, the existence of aggrgation are demonstrated in 1×10^-5mol/L to 1×10^-6mol/L concentration range.The result show that aggregation of CuPc depends on the nature of substitutent group, solvent polarity and central metal.The apparent aggregation constant and apparent aggregation number are determined.

1993, 11(4): 371-371. DOI: 10.7517/j.issn.1674-0475.1993.04.371

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