- Synthesis f Mixed Oligomeric Heteroarylenes containing Thiophene and Selenophene Rings; their U.V.Spectra and Oxidation Potentials
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Mixed oligomers containing thiophene and selenophene rings have been synthesized; their u.v. spectra and oxidation potentials determined and discussed in terms of coplanarity of the rings and the +I-effect of the methyl substituent.
- Shabana, R.,Galai, A.,Mark, Harry B.,Zimmer, Hans,Gronowitz, Salo,Hoernfeldt, A. B.
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- Evidence of a Photoinduced Electron-Transfer Mechanism in the Fluorescence Self-quenching of 2,5-Substituted Selenophenes Prepared through in Situ Reduction of Elemental Selenium in Superbasic Media
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A series of new 2,5-disubstituted selenophene derivatives are described from elemental selenium and 1,3-diynes in superbasic media. The activation of elemental selenium in a KOH/DMSO system allows cyclization with conjugated diynes at room temperature. The cyclization reaction is extended to a broad range of functional groups, for which photophysics were experimentally and theoretically investigated. The selenophene derivatives present absorption maxima in the UV-A region and fluorescence emission in the violet-to-blue region. Fluorescence decay profiles were obtained showing a monoexponential decay with fast fluorescence lifetimes (~0.118 ns), as predicted by the Strickler-Berg relations. In general, in both investigations, no dependence on the solvent polarity on the absorption and emission maxima location was observed. On the other hand, solvents and substituents are shown to play a role in the fluorescence quantum yield values. In addition, a fluorescence self-quenching behavior could be observed, related to a photoinduced electron-transfer mechanism. Theoretical calculations performed at the MP2/ADC(2)/cc-pVDZ level of theory were performed in order to investigate the photophysical features of this series of selenophene derivatives.
- De Salles, Helena Domingues,Coelho, Felipe Lange,Paix?o, Douglas Bernardo,Barboza, Cristina Aparecida,Da Silveira Rampon, Daniel,Rodembusch, Fabiano Severo,Schneider, Paulo Henrique
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p. 10140 - 10153
(2021/07/31)
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- 2,5-disubstituted selenophen compound and synthesis method thereof
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The invention belongs to the technical field of organic synthesis, and discloses a 2,5-disubstituted selenophen compound and a synthesis method thereof. The synthesis method comprises the following steps: adding an alkynyl-terminated compound, elemental s
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Paragraph 0128-0136
(2020/06/24)
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- Selenophene anti-tumor agents
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Novel selenophene compounds useful as anti-tumor agents are described. Preferred compounds include compounds of formula I: wherein R1 and R2 are independently selected from the group consisting of, H, CHO, CH2OH and CH2NH2; and X and Y are independently selected from the group consisting of Se, S, O, NCH3 and NH. Pharmaceutical compositions and a method for treating patients having tumors utilizing the disclosed selenophene compounds are also described.
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- SYNTHESIS OF MIXED OLIGOMERIC HETEROARYLENES CONTAINING FURAN, THIOPHENE, AND SELENOPHENE RINGS; THEIR UV SPECTRA AND OXIDATION POTENTIALS
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Mixed oligomeric five-membered heteroarylenes 3a-f and 4a-e have been prepared by cross-coupling reaction of the Grignard reagents 2 derived of the appropriately substituted thiophenes 1 with either the 2-bromoheteroarylenes or the 2,5-dibromoheteroarylenes derived of furan, thiophene, and/or selenophene respectively.The UV spectra and oxidation potential of compounds 3a-f and 4a-e are discussed on the basis of co-planarity. Key words; Conducting polymers; oligomeric heteroarylenes; UV spectra; oxidation potentials.
- Zimmer, Hans,Shabana, R.,Galal, A.,Mark, H. B.,Gronowitz, S.,Hoernfeldt, A. -B.
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p. 171 - 176
(2007/10/02)
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