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卷 480, 编号 1 (2018)
- 年: 2018
- 文章: 8
- URL: https://journals.rcsi.science/0012-5008/issue/view/9293
Chemistry
Porphyrin Derivatives of Macrocyclic Tetraindoles: Synthesis and Chemical Transformations
摘要
Polyphenols chemically bonded to a molecular platform based on macrocyclic tetraindole porphyrin derivatives were synthesized for the first time. The tetraindole was prepared by two-step tetramerization of 3-(4′-bromophenyl)-4,6-dimetoxyindole. Polyphenols of this type were obtained by the Suzuki–Miyaura reaction between bromo-containing cyclic tetraindole and monoboryl-substituted porphyrin. The subsequent transformations of this molecular construction gave rise to epoxidized polyphenol on a tetraindole support, which served for the development of a new negative resist for electron-beam nanolithography. The resist can form patterns with a 12 nm resolution.
77-80
New Salt Spiropyran of Indoline Series with Fluorine Substituent
摘要
Synthesis, study of structure and photochromic properties of new salt spiropyran of indoline series containing a fluorine substituent in the 6′-position of the 2H-chromene moiety have been described in the work. The structure of the compound has been confirmed by 1H NMR spectroscopy and X-ray diffraction analysis. Comparison of the structure of the compound with the previously studied analogue containing a methyl group instead of a fluorine atom in the 6′-position of the [2H]-chromene moiety has been made. This compound has been found to be photochromic, long-wavelength absorption maximum of its open form shows a bathochromic shift, and lifetime is increased three times as compared with the methyl analogue.
81-84
The Homogeneity Range of Crystalline Tris(8-hydroxyquinoline)gallium
摘要
An experimental procedure has been developed for constructing pi–T diagrams (partial vapor pressure of the ligand-forming component–temperature) for luminescent metal complexes with symmetric organic ligands. The partial 8-hydroxyquinoline vapor pressure–temperature diagram has been constructed for tris(8-hydroxyquinoline)gallium electrophosphor (Gaq3) in the temperature range 300–617 K at 8-hydroxyquinoline vapor pressures 10–3–104 Pa, where the homogeneity ranges of different Gaq3 polymorphs have been determined. Structure-sensitive properties of crystalline materials can be tailored by changing synthesis conditions within the homogeneity range of a phase.
85-88
An Alternative Approach to the Synthesis of Poly(naphthoylenebenzimidazole)s
摘要
An alternative approach to the synthesis of poly(naphthoylenebenzimidazole)s in supercritical carbon dioxide has been accomplished without use of hazardous chemical solvents, which resulted in preparation of high-purity polymers by a more efficient contemporary method. A series of poly(naphthoylenebenzimidazole) s has been obtained at 90°C and 15 MPa for 8 h with the use of a mixture of benzoic acid and benzimidazole as a catalyst. Certain properties of the synthesized polymers have been studied.
89-92
Homolytic Decomposition of Sulfonyl Chlorides
摘要
The products, kinetic parameters, and activation entropy of thermal decomposition of sulfonyl chloride groups in chlorosulfonated polyethylene (CSPE) have been studied for the first time, and it has been demonstrated that the decomposition mechanism involves simultaneous cleavage of two bonds (carbon–sulfur and sulfur–chlorine) to give an SO2 molecule and two free radicals, which can be useful in the process of polymer structuring. The radical mechanism has been confirmed by the formation of 2,3-diphenyl-2,3- dimethylbutane on heating CSPE in isopropylbenzene. The simultaneous cleavage of two bonds is supported by the low activation energy and pre-exponential factor in the Arrhenius equation, as well as by negative activation entropy values.
93-95
Photochemical Synthesis of Anisotropic Silver Nanoparticles in Aqueous Solutions in the Presence of Sodium Citrate
摘要
The rapid one-step photochemical synthesis of anisotropic silver nanoparticles (ANPs) is reported. Silver ANPs were prepared from silver nitrate by a citrate route in aqueous solutions at room temperature under exposure to unfiltered light of a DRK 120 high-pressure mercury lamp. The silver ANPs form through one-electron reduction of the silver cation in its chelate complex with the production of sodium citrate photolysis. In the course of synthesis, small charged silver clusters and nanoparticles are formed first, which are then stabilized by citrate ions. Key factors that influence the synthesis of silver ANPs and their further transformation have been determined.
96-98
Concentration Space of Homogeneous Garnet in the System Ga2O3–(Y, Bi)3(Fe, Ga)5O12–Fe2O3
摘要
The concentration space of homogeneous garnet in the system Ga2O3–(Y, Bi)3(Fe, Ga)5O12–Fe2O3 was determined by X-ray powder diffraction analysis. The obtained results expand the knowledge of the possible variations of cation ratios Y : Bi : Fe : Ga in garnet, which can be used for searching for and creating new stable magneto-optical materials.
99-102
Chemical Technology
Solid-Phase Synthesis in the Technology of Functional Materials Based on Titanium(IV)
摘要
A study was made of structural, morphological, and chemical transformations in solid-phase systems based on sulfate, oxide, and hydroxide compounds of titanium(IV) under the intense mechanical activation of solid particles. This enabled one to substantiate the phase formation mechanism initiated by the intense homogenization of the reaction mixture, which is accompanied by a decrease in the particle size, deformation of the particle structure, and the formation of a new active surface. The obtained results formed the physicochemical basis for developing an innovative nonwaste technology for producing a new grade of titanium dioxide in the rutile modification from titanium sulfate salt under a program performed by the Roscosmos State Corporation for Space Activities.
103-105