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Redox Properties of Conjugated Phosphole Derivatives – Electrochemical Study
Koláčná, Lucie ; Polák, P. ; Tobrman, T. ; Ludvík, Jiří
The study describes pentasubstituted phospholes with a π-conjugated arms in positions 2 and 5 of the phosphole ring. According to the expectations, substituents with electron-donating groups led to lower oxidation potentials, the presence of electron-withdrawing groups shifts the reduction potential to less negative values. Because all studied phospholes have multiple substituents of both types, their resulting potentials represent the sum of their influences. Moreover, since many of the studied compounds have two redox centers (phosphole moiety itself and the pi-conjugated arm), their locations were determined and intramolecular interactions were followed, because substituents which can be conjugated with the π-system of phosphole are able to extend the delocalized π-system resulting in stabilization of primary redox intermediates. Chemical modification of phospholes using various combinations of substituents can set the desired electrochemical properties of studied molecules.
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Synthesis and properties of supramolecular polymers
Vitvarová, Tereza ; Vohlídal, Jiří (advisor) ; Jindřich, Jindřich (referee) ; Royal, Guy (referee)
New π-conjugated building blocks (unimers) for metallo-supramolecular polymers (MSPs), whose comprise: (i) substituted phosphole ring surrounded by two thiophene rings as the central block, (ii) 2,2':6',2''-terpyridine-4'-yl (tpy) end-groups as ion-selectors, and (iii) different linkers inserted between the central block and tpy end-groups, are described. Chemical and physical properties of those unimers were studied with attention on correlation between properties and structure of unimers. For example the unimer without linkers shows the UV/vis absorption maximum red shifted about 60 to 100 nm compared to bis(tpy)terthiophenes, which proves that replacing of the thiophene with phosphole unit significantly enhances the delocalization of electrons within the unimer molecule and significant area of absorption spectra can be covered. Introduction of linkers (ethynediyl, ethynediyl-thiophene-2,5-diyl, ethynediyl-1,4-phenylene) has a minor effect on the bandgap energy. All prepared unimers underwent self-assembling process with various metal ions (Co2+ , Cu2+ , Fe2+ , Ni2+ and Zn2+ ) resulting into metallo-supramolecular polymers. Three stages of the assembly of unimers into related MSPs were observed and characterized by absorption, fluorescence spectroscopy and size exclusion chromatography: 1)...
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Synthesis and properties of supramolecular polymers
Vitvarová, Tereza
New π-conjugated building blocks (unimers) for metallo-supramolecular polymers (MSPs), whose comprise: (i) substituted phosphole ring surrounded by two thiophene rings as the central block, (ii) 2,2':6',2''-terpyridine-4'-yl (tpy) end-groups as ion-selectors, and (iii) different linkers inserted between the central block and tpy end-groups, are described. Chemical and physical properties of those unimers were studied with attention on correlation between properties and structure of unimers. For example the unimer without linkers shows the UV/vis absorption maximum red shifted about 60 to 100 nm compared to bis(tpy)terthiophenes, which proves that replacing of the thiophene with phosphole unit significantly enhances the delocalization of electrons within the unimer molecule and significant area of absorption spectra can be covered. Introduction of linkers (ethynediyl, ethynediyl-thiophene-2,5-diyl, ethynediyl-1,4-phenylene) has a minor effect on the bandgap energy. All prepared unimers underwent self-assembling process with various metal ions (Co2+ , Cu2+ , Fe2+ , Ni2+ and Zn2+ ) resulting into metallo-supramolecular polymers. Three stages of the assembly of unimers into related MSPs were observed and characterized by absorption, fluorescence spectroscopy and size exclusion chromatography: 1)...
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Synthesis and properties of supramolecular polymers
Vitvarová, Tereza
New π-conjugated building blocks (unimers) for metallo-supramolecular polymers (MSPs), whose comprise: (i) substituted phosphole ring surrounded by two thiophene rings as the central block, (ii) 2,2':6',2''-terpyridine-4'-yl (tpy) end-groups as ion-selectors, and (iii) different linkers inserted between the central block and tpy end-groups, are described. Chemical and physical properties of those unimers were studied with attention on correlation between properties and structure of unimers. For example the unimer without linkers shows the UV/vis absorption maximum red shifted about 60 to 100 nm compared to bis(tpy)terthiophenes, which proves that replacing of the thiophene with phosphole unit significantly enhances the delocalization of electrons within the unimer molecule and significant area of absorption spectra can be covered. Introduction of linkers (ethynediyl, ethynediyl-thiophene-2,5-diyl, ethynediyl-1,4-phenylene) has a minor effect on the bandgap energy. All prepared unimers underwent self-assembling process with various metal ions (Co2+ , Cu2+ , Fe2+ , Ni2+ and Zn2+ ) resulting into metallo-supramolecular polymers. Three stages of the assembly of unimers into related MSPs were observed and characterized by absorption, fluorescence spectroscopy and size exclusion chromatography: 1)...
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Synthesis and properties of supramolecular polymers
Vitvarová, Tereza ; Vohlídal, Jiří (advisor) ; Jindřich, Jindřich (referee) ; Royal, Guy (referee)
New π-conjugated building blocks (unimers) for metallo-supramolecular polymers (MSPs), whose comprise: (i) substituted phosphole ring surrounded by two thiophene rings as the central block, (ii) 2,2':6',2''-terpyridine-4'-yl (tpy) end-groups as ion-selectors, and (iii) different linkers inserted between the central block and tpy end-groups, are described. Chemical and physical properties of those unimers were studied with attention on correlation between properties and structure of unimers. For example the unimer without linkers shows the UV/vis absorption maximum red shifted about 60 to 100 nm compared to bis(tpy)terthiophenes, which proves that replacing of the thiophene with phosphole unit significantly enhances the delocalization of electrons within the unimer molecule and significant area of absorption spectra can be covered. Introduction of linkers (ethynediyl, ethynediyl-thiophene-2,5-diyl, ethynediyl-1,4-phenylene) has a minor effect on the bandgap energy. All prepared unimers underwent self-assembling process with various metal ions (Co2+ , Cu2+ , Fe2+ , Ni2+ and Zn2+ ) resulting into metallo-supramolecular polymers. Three stages of the assembly of unimers into related MSPs were observed and characterized by absorption, fluorescence spectroscopy and size exclusion chromatography: 1)...
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