- 1,2,5-chalcogenadiazole-annulated tripyrazinoporphyrazines: Synthesis, spectral characteristics, and influence of the heavy atom effect on their photophysical properties
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A series of low-symmetry ZnII, MgII, and metal-free porphyrazine derivatives with one 1,2,5-chalcogenadiazole ring (with S, Se or Te) and three pyrazines bearing tert-butylsulfanyls were synthesized. The absorption maxima of ZnII complexes lay at 660, 674, and 707 nm for S, Se, and Te, respectively, indicating increasing contribution of the 1,2,5-chalcogenadiazole rings to the π-electronic system. Photophysical studies revealed that introduction of Se as a chalcogen and ZnII as a central metal causes an increase in the singlet oxygen quantum yield, reaching a value of 0.81, whereas the combination of S and MgII gives only 0.39. This takes place on the account of the fluorescence quantum yields that differ significantly from 0.072 (ZnII+Se) to 0.51 (MgII+S). These results demonstrated the two-dimensional heavy atom effect combining the role of the chalcogen (first dimension) as well as the central metal (second dimension). Attempts to prepare oxygen-containing isologues led to the formation of an unexpected side product.
- Svec, Jan,Zimcik, Petr,Novakova, Lucie,Rakitin, Oleg A.,Amelichev, Stanislav A.,Stuzhin, Pavel A.,Novakova, Veronika
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p. 596 - 604
(2015/01/30)
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- Cross-linking of discotic tetraazaporphyrin dyes in 2 and 3 dimensions by "click" chemistry
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An intrinsic shortcoming of self-organizing materials is their susceptibility to structural changes by mechanical forces and exposure to chemicals and radiation. Cross-linking of the molecules in the desired supramolecular structure is a generally applicable pathway to structurally more stable materials but is difficult to apply to self-organizing materials because the introduction of cross-linkable groups affects their self-organization and the process of cross-linking may alter the supramolecular structure of the preceding phase. Reported here are the synthesis, thermal properties, and cross-linking of octaalkylthio substituted tetraazaporphyrins that contain either eight terminal azide groups or eight terminal acetylene groups. Synthesis of these compounds requires the preparation of the azide and alkyne containing side-chains and their reaction with 1,2-dicyanoethylene-1,2-dithiolate to the corresponding maleodinitrile intermediates. All maleodinitriles are successfully converted to tetraazaporphyrins by the established Mg templated cyclotetramerization in typical yields of 60-70%. Thermal properties of the metal-free and copper(ii) metallated tetraazaporphyrins were studied by thermal gravimetric analysis, polarized optical microscopy, differential scanning calorimetry, and variable temperature powder X-ray diffraction measurements. Azide substituted tetraazaporphyrins with trimethylene and hexamethylene spacers as well as acetylene derivatives with trimethylene spacers unexpectedly display columnar mesophases over ranges of temperature from 30 °C to 110 °C. A thermally activated cross-linking of a hexagonal columnar mesophase by cycloaddition at 65 °C is demonstrated for a 1:::1 mixture of azide and acetylene derivatives. At this temperature the reaction progresses for up to 48 hours but renders the mesophase insoluble and stable to above 200 °C. The structure of the mesophase is surprisingly little affected by the cross-coupling process that reaches a conversion of 60% of all azide and acetylene groups based on IR measurements. Conversion of up to 80% of azide and acetylene groups is reached by copper catalysed cross-linking of a 1:::1 mixture in solution to generate insoluble polymers. A similar degree of conversion is achieved by copper catalysed cross-linking of a 1:::1 mixture as Langmuir film after 3 hours. However, transfer of intact cross-linked Langmuir films onto substrates was not successful.
- Kayal, Himadri,Ahmida, Mohamed M.,Dufour, Scott,Taing, Hi,Eichhorn, S. Holger
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p. 7064 - 7072
(2013/10/22)
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- Synthesis, photophysical and electrochemical properties of a D-σ-A ensemble derived from porphyrazine and tetrathiafulvalene
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Cis/trans 1,2-dicyanoethylenes bearing tetrathiafulvalene units linked by a ethylenedithio spacer were prepared. The eis isomer was converted to eight tetrathiafulvalene unit substituted magnesium porphyrazine upon a metal-templated cyclotetramerization with magnesium propoxide in propanol. The dicyanoethylenes and target compound were characterized by EA, NMR, and MALDI-TOF mass and photophysical and Electrochemical properties were discussed.
- Hou, Ruibin,Qiu, Han,Chen, Tie,Yin, Bingzhu
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experimental part
p. 1799 - 1805
(2009/12/07)
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- TETRAAZAPORPHYRIN-BASED COMPOUNDS AND THEIR USES
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Asymmetrically substituted metal-phthalocyanine compounds are disclosed. These compounds and other phthalocyanine-derivatives are used in bioimaging, bioanalysis, FRET and quenching techniques, photodynamic therapy, DNA analysis for cells, proteins, tissues and other biological entities, and other applications. Near- infrared fluorescence minimizes matrix effects typically seen in other methods of analyzing biochemical entities in cells, proteins, tissues and other biological entities.
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Page/Page column 30
(2008/06/13)
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- Process for the preparation of pure alkaline earth alkoxides
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Production of a metal-free Group II alkaline earth dimethanolate involves alcoholysis of the corresponding diethanolate with an excess of methanol.
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Page/Page column 3; 4
(2008/06/13)
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- Process for the preparation of pure alkaline earth alkoxides
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Production of metal-free, alkoxide-pure alkaline earth alkoxides involves use of an excess of an alcohol to effect alcoholytic alkoxide group exchange in solutions of optionally mixed alkoxides having shorter alkyl chains than the final product, the optionally mixed alkoxides being at least proportionately dissolved during the reaction. Production of metal-free, alkoxide-pure alkaline earth alkoxides of formula (I) involves alcoholysis of a solution of an optionally mixed alkoxide of formula (II) with an excess of an alcohol of formula (III), compound (II) being at least proportionately dissolved during the reaction. M(OR 1>) 2(I) M(OR 2>) x(OR 3>) y(OR 4>) z(II) HOR 1>(III) M : main Group II element; R 1>linear or cyclic 2-20C alkyl in (I) but is different from R 2>- R 4>in (II) in having at least one more carbon atom in the alkyl chain than the longest chain in R 2>- R 4>; R 2>- R 4>1-4C alkyl; and x, y and z : 0-2, with x + y + z = 2.
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Page/Page column 8
(2008/06/13)
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- Process for preparing 1-methylindazole-3-carboxylic acid
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A method of performing a bearer path assurance test across a packet-based IP network is provided. The method includes establishing a bearer path across the IP network and performing a bearer path assurance test during call setup before cutting through the call. The method can also include creating a timestamp at the originating office, sending the timestamp from the originating office to a terminating office, sending the timestamp from the terminating office to the originating office, receiving the timestamp at the originating office, and verifying the continuity of the bearer path. The method can also include evaluating round trip delay and packet loss using one or more timestamps.
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- Macrocyclic porphyrazine-type compounds, metal derivatives thereof and process for their preparation
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The invention relates to new macrocyclic phthalocyanine-like systems. In particular, object of the invention are new macrocyclic porphyrazine-type compounds and metal derivatives thereof, in which heterocycle rings are provided at the periphery of the inner porphyrazine fragment. A further object of the invention is a process for obtaining, as an example, tetra(thiadiazolo)porphyrazine, or tetra(selenediazolo)porphyrazine, by means of cyclotetramerization of the monomers 3,4-dicyano-1,25-thiadizole, or 3,4-dicyano-1,2,5-selenodiazole with metallorganico or inorganic salts, in organic solvents, extraction, if any, of the metal from the complexes thus formed by treatment with strong acids to obtain tetra(thiadiazolo)porphyrazine, or tetra(selenediazolo)porphyrazine, and by treatment, if any, of these compounds with a metallorganic or inorganic salt to obtain the metal derivatives thereof different from those previously extracted.
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Page column 4
(2010/01/30)
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- Syntheses of octa(2-heteroaryl) azaphthalocyanines
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Magnesium, copper(II) and nickel(II) complexes of octasubstituted azaphthalocyanines 3-5 have been prepared from di-fur-2-yl, di-thien-2-yl and di-pyrid-2-yl pyrazine-2,3-dicarbonitriles 2. Compounds 2 were prepared in good yields from condensations of diaminomaleonitrile and the diketones 2,2′-furil, 2,2′-thenil and 2,2′-pyridil. AzaPcs 3-5 give green pyridine solutions with Q-bands at 650-670 nm and ε-values of 60 000-190 000. Wiley-VCH Verlag GmbH, 2000.
- Morkved, Eva H.,Ossletten, Hege,Kjosen, Helge,Bjorlo, Olav
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- Preparation of octa(alkoxy) azaphthalocyanines
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5,6-Bis(alkoxy)pyrazine-2,3-dicarbonitriles 3, with methoxy-, ethoxy-and propoxy-substituents, were allowed to react with magnesium alkoxides to form the corresponding magnesium octa(alkoxy)azaphthalocyanines 5a,d,e. Compound 5a was converted into the metal-free azaphthalocyanine 5b, and to the copper complex 5c. The propoxy substituted magnesium azaphthalocyanine 5e was converted to the metal free azaphthalocyanine 5f. Both 5e and 5f are readily soluble in organic solvents. The stable intermediate methyl 2,3-di(methoxy)-6-cyanopyrazine-5-carboximidate 4, was obtained both from a reaction of 5,6-dichloropyrazine-2,3-dicarbonitrile 1, with sodium methoxide in methanol, and in a sodium methoxide catalyzed reaction of 3a with ammonia in methanol. Compound 4 was converted into 5a with magnesium methoxide, and is therefore an intermediate between 3a and 5a.
- Morkved, Eva H.,Ossletten, Hege,Kjosen, Helge
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p. 1117 - 1121
(2007/10/03)
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- Synthesis of benzyl/allyl alkyl ethers from corresponding magnesium alkoxides
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In the presence of iodine, alcohols react with magnesium to produce magnesium alkoxides which are then treated with benzyl chloride or allyl bromide to produce benzyl alkyl ethers or allyl alkyl ethers.
- Lin, Ji-Mao,Li, Hui-Hui,Zhou, Ai-Min
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p. 5159 - 5160
(2007/10/03)
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- Determination of Gas-Phase Ligand Binding Energies to Mg+ by FTMS Techniques
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Relative and absolute gas-phase binding energies of 12 organic molecules to Mg+ have been determined by four different methods involving Fourier transform mass spectrometry (FTMS).Mg+ is generated in the FTMS cell by pulsed laser ionization and reacts with the organic compounds to give MgL+ either by direct condensation or by a fast two-step displacememt reaction.The equilibrium constant (Keq) and the absolute rate constants (kf and kr) are obtained for the ligand exchange reaction: MgL+ + L' MgL'+ + L.The equilibrium constants are converted to free-energy differences and relative binding energies are calculated to give the Do(Mg+-L) scale.Entropy changes are assumed to be small and they are discussed in detail.The absolute gas-phase binding energies Do(Mg+-MeOH) and Do(Mg+-Me2CO) are assigned from equilibrium and photodissociation experiments to be 61 +/- 5 and 67 +/- 5 kcal/mol, respectively.The correlation of results from the different methods give a scale of relative and absolute bond energies to Mg+ for the 12 organic molecules examined.The results for Mg+ are compared with previously reported results on H+, CpNi+, Al+, Mn+, and Cu+.These comparisons show for this limited study on oxygen bases that Mg+ is a softer acid than H+ and Al+, very similar in acidity to Mn+ and Cu+, and a harder acid than CpNi+.
- Operti, Lorenza,Tews, Edward C.,Freiser, Ben S.
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p. 3847 - 3853
(2007/10/02)
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