Synthesis and photochromic and fluorescence properties of 3-(1-benzyl-5-methoxy-2-methylindolyl)-4-thienyl-substituted furan(pyrrole)-2,5-diones

New nonsymmetrical dihetarylethenes, 3-(1-benzyl-5-methoxy-2-methyl-1H-indol-3-yl)-4-(3-thienyl)furan-2,5-dione and 1-alkyl- and (1-aryl)-3-(1-benzyl-5-methoxy-2-methyl-1H-indol-3-yl)-4-(3-thienyl)-1H-pyrrole-2,5-dione, exhibiting photochromic properties in solutions were synthesized. Noncyclic isomers of dihetarylethenes show fluorescence with quantum yields up to 0.13.     

Zinc(II) and cadmium(II) <Emphasis Type="Italic">N</Emphasis>,<Emphasis Type="Italic">N</Emphasis>'-Bis(2-<Emphasis Type="Italic">N</Emphasis>-Tosylaminobenzylidene) diaminodipropyliminates: Syntheses,structures, and photoluminescence properties

Chemical and electrochemical syntheses of the zinc(II) and cadmium(II) complexes with the tetradentate Schiff base (H₂L), the condensation product of 2-N-tosylaminobenzaldehyde with diaminodipropylamine, are carried out. The structures, compositions, and properties of the synthesized metal complexes are studied by elemental analyses, IR spectroscopy, ¹H NMR, UV spectroscopy, X-ray absorption spectroscopy, and quantum-chemical calculations. The structure of the cadmium(II) complex is determined by X-ray diffraction analysis (CIF file CCDC no. 1446393). The cadmium(II) and zinc(II) complexes exhibit luminescence in a CH₂Cl₂ solution in the blue spectral range (λ_PL = 425–428 nm) with the photoluminescence quantum yields ? = 0.20 and 0.75, respectively.     

Synthesis,structure, and photoluminescence properties of bis[2-(1,3-benzoxazol-2-yl-κ<Emphasis Type="Italic">N</Emphasis>)-4,5-dichloro-3-(ethoxycarbonyl)phenolato-κ<Emphasis Type="Italic">O</Emphasis>]zinc(II)

The structure of bis[2-(1,3-benzoxazol-2-yl-κN)-4,5-dichloro-3-(ethoxycarbonyl)phenolato-κO]-zinc(II) was determined by IR and ¹H and ¹³C NMR spectroscopy, and its structural characteristics were estimated by quantum chemical calculations. The complex showed photoluminescence properties.     

Synthesis, structures, and photochromic properties of N-aryl-3-indolylfulgides

New 3-indolylfulgides, viz., 3-[1-(1-aryl-5-methoxy-2-methyl-1H-indol-3-yl)ethylidene]-4-(1-methylethylidene)tetrahydro-2,5-furandiones, were synthesized. These compounds were obtained as E-isomers, as demonstrated by X-ray diffraction, electronic spectroscopy, and ¹H NMR spectroscopy. Fulgides exhibit photochromic properties in solution. The cyclic dihydrocarbazole photoisomers of indolylfulgides show fluorescence properties and are characterized by high thermal stability. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 7, pp. 1417–1423, July, 2008.     

Spiropyrans and spirooxazines 9. Photochromism of novel cationic spirooxazines

Novel photochromic spirooxazinoquinolines, their cationic derivatives, and cationic spirooxazine containing pyridinium cation in the aliphatic side chain of the oxazine moiety of the molecule were synthesized. Quaternization of the quinoline fragment leads to a substantial increase in the thermal stability of the merocyanine isomers of cationic spirooxazines and a decrease in the efficiency of photocoloration. Pyridinium cation in the aliphatic side chain of the spirooxazine does not exert a substantial effect on the kinetics of photocoloration and thermal bleaching.     

Structure and photochromic transformations of fulgides of the indole series

Previously undescribed fulgides of the indole series, viz., (1-methyl-3-indolylmethylene)- and (1-methyl-3-indolylethylidene) (isopropylidene)succinic anhydride, were synthesized. A Z conformation for (1-methyl-3-indolylmethylene) (isopropylidene)succinic anhydride and an E configuration for (1-methyl-3-indolylethylidene)-(isopropylidene) succinic anhydride were established by electronic and PMR spectroscopy and x-ray diffraction analysis. The photochromic properties of fulgides were observed and investigated. A scheme of photoinduced and thermal transformations of fulgides that includes a step involving Z E isomerization in the excited state is proposed. An additional photoisomer was recorded by pulse photolysis and fluorescence.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 1, pp. 33–41, January, 1990.     

New model of the hydroxylating enzyme system of liver microsomes: NADH-riboflavine-hemoglobin-O2

The kinetics of aniline hydroxylation to p-aminophenol by the NADH-riboflavine-hemoglobin-O₂ system has been investigated in a phosphate buffer (pH 6.8) at 37°C. At optimal concentrations of the model system components the rates of aniline oxidation are comparable with those of the enzymatic hydroxylation of aniline by rat liver microsomes. Possible paths of aniline hydroxylation in the system NADH-riboflavine-hemoglobin-O₂ are discussed.

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37°C pH 6,8 - .---O₂. . .---O₂.

     

Application of topological indexes to predict immunomodulating activity of new peptides

The application of topological indexes to codify the structures of peptide immunomodulators — analogs of taftsin — and to predict the pharmacological activity of new compounds by the κ-neighbor and neural network methods is described. It is shown that if the conformational state of the model compound is chosen correctly, topological indexes can be used successfully for effective screening in the development of new medicinals with corresponding mechanisms of action. Institute of Bioorganic Chemistry and Petrochemistry, Ukraine National Academy of Sciences, Ukraine, 252660 Kiev-94, 1 Murmanskaya Ulitsa. Translated from Teoreticheskaya i éksperimental’naya Khimiya, Vol. 33, No. 2, 100–104, March–April, 1997.