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Byla provedena literární rešerše v oblasti fotoredox katalýzy organickými substancemi, ze které vyplynulo šest skupin organických sloučenin nejčastěji využívaných ve fotoredox katalýze viditelným světlem. Byly shrnuty jejich základní fotofyzikální a elektrochemické vlastnosti a jejich využití v konkrétních fotoredox reakcích. V experimentální části byla provedena optimalizace přípravy již známého katalyzátoru. Dále byly provedeny strukturní modifikace tohoto katalyzátoru, které vedly k sedmnácti dalším sloučeninám s akceptorní části na bázi pyrazin-2,3-dikarbonitrilu, pyrazin-3,5-dikarbonitrilu, pyridin-2,6-dikarbonitrilu, pyridin-4-karbonitrilu a pyridin-3,5-dikarbonitrilu. Donorními částmi těchto sloučenin byl thiofen, 2-methoxythiofen a jeho kombinace s trojnou vazbou, 2-methylthiothiofen, methoxy nebo thiomethyl skupina. Všechny připravené sloučeniny byly plně spektrálně charakterizovány, jejich fundamentální vlastnosti byly dále studovány pomocí rentgenostrukturní analýzy, elektrochemických měření, absorpční a emisní spektroskopie, které byly podpořeny teoretickými DFT kalkulacemi. Vztahy mezi strukturou a katalytickými vlastnostmi byly dále studovány ve třech fotoredoxních reakcích, které zahrnují zkřížený dehydrogenativní kapling a anulační reakce., A literature search focusing on visible light photoredox catalysis that utilizes organic substances has been accomplished. Overall, six classes of organic substances currently used as photoredox catalysts have been found and their phophysical and electrochemical properties and use in photoredox reactions has been summarized. The experimental part focuses on optimizing synthesis of the known photocatalyst. Subsequently, structural modifications of the original catalyst have been carried out leading to seventeen catalysts with acceptor part based on pyrazine-2,3-dicarbonitrile, pyrazine-3,5-dicarbonitrile, pyridine-2,6-dicarbonitrile, pyridine-4-carbonitrilu and pyridine-3,5-dicarbonitrile. Various peripheral donors such as thiophene, 2-methoxythiophene (in a combination with acetylene linker), 2-methylthiothiophene, methoxy or thiomethyl moiety were employed. All synthesized catalysts were fully spectrally characterized and their fundamental properties were further investigated by X-ray analysis, electrochemistry, electronic absorption and emission spectra. The experimental results were supported by theoretical DFT calculations. Structure vs. catalytic activity relationship have been elucidated in three photoredox reactions including cross-dehydrogenative coupling and annulation reactions., Fakulta chemicko-technologická, Dokončená práce s úspěšnou obhajobou

Our group started a research program in acetylene chemistry in 1987; since then, an intense research effort led to a fascinating journey into acetylenic scaffolding, aimed at exploring conjugative and optoelectronic properties of acetylenic chromophores. This journey included the generation of a unique molecular construction kit for acetylenic scaffolding, consisting of (E)-1,2-diethynylethenes [DEEs, (E)-hex-3-ene-1,5-diynes], tetraethynylethenes (TEEs, 3,4-diethynylhex-3-ene-1,5-diynes), chiral 1,3-diethynylallenes (DEAs, hepta-3,4-diene-1,6-diynes), 1,4-di and 1,1,4,4-tetraethynylbutatrienes, chiral trialkynylmethanes, and 1,1,2,2-tetraethynylethanes. These building modules were subsequently applied to the synthesis of carbon-rich architectures extending into one, two, and three dimensions. They include multinanometer-long monodisperse oligomers as models for infinite acetylenic polymers, molecular switches, perethynylated dehydroannulenes, expanded radialenes, and radiaannulenes, and an octamethoxy-substituted expanded cubane with a central C56 core. Donor-substituted cyanoethynylethenes (CEEs) and 1,1,4,4-tetracyanobuta-1,3-dienes (TCBDs) were introduced as new push-pull chromophores featuring intense intramolecular charge-transfer (CT) interactions. Dendritic multivalent CT chromophores were constructed using atom-economic, "click"-like reactions, and these systems were shown to behave as "molecular batteries", featuring exceptional electron uptake and storage capacity. The research finally led to the development of an unprecedented cascade reaction for the preparation of dendritic and oligomeric donor-acceptor (D-A) molecules. New [AB]-type oligomers become accessible in domino reactions involving repetitive sequences of [2+2] cycloadditions of tetracyanoethylene (TCNE) and tetrathiafulvalene (TTF) to polyynes, followed by retro-electrocyclizations

We disclose a supramolecular material that combines semiconducting and dipolar functionalities. The material consists of a discotic semiconducting carbonyl-bridged triarylamine core, which is surrounded by three dipolar amide groups. In thin films, the material self-organizes in a hexagonal columnar fashion through Jr-stacking of the molecular core and hydrogen bonding between the amide groups. Alignment by an electrical field in a simple metal/semiconductor/metal geometry induces a polar order in the interface layers near the metal contacts that can be reversibly switched, while the bulk material remains nonpolarized. On suitably chosen electrodes, the presence of an interfacial polarization field leads to a modulation of the barrier for charge injection into the semiconductor. Consequently, a reversible switching is possible between a high-resistance, injection-limited off-state and a low-resistance, space-charge-limited on-state. The resulting memory diode shows switchable rectification with on/off ratios of up to two orders of magnitude. This demonstrated multifunctionality of a single material is a promising concept toward possible application in lowcost, large-area, nonvolatile organic memories., Funding Agencies|NWO Nano program; Bavarian State Ministry of Science, Research, and the Arts for the Collaborative Research Network Solar Technologies go Hybrid; Deutsche Forschungsgemeinschaft (DFG) [SFB 953]; Vetenskapsradet [2015-03813]

Kyselina barbiturová a její deriváty mohou vystupovat jako dobré elektron-akceptorní jednotky v push-pull chromoforech. V této práci byly popsány metody příprav barbiturové kyseliny včetně jejího následného zakomponování do push-pull systémů. Dále bylo pojednáno o využití chromoforů s akceptorní barbiturovou jednotkou jako sloučenin s vnitřním přenosem náboje a nelineárně optickými vlastnostmi. Bylo syntetizováno dvanáct chromoforů s N,N´ dibutylbarbiturovou akceptorní jednotkou a ty byly dále zkoumány pomocí rentgenostrukturní analýzy, elektrochemie, UV-VIS absorpční spektroskopie a výpočetními metodami., Barbituric acid and its derivatives may act as good electron-acceptor units in push-pull chromophores. In this work, the methods of barbituric acid preparation and its subsequent incorporation into the push-pull systems have been described. Utilization of chromophores with barbituric acceptor unit as compounds with intramolecular charge-transfer and nonlinear optical properties has also been discussed. Twelve chromophores with N,N´ dibuthylbarbituric acceptor unit were synthesized and further investigated by X ray analysis, electrochemistry, UV-VIS absorption spectroscopy and computational methods., Ústav organické chemie a technologie, Konfigurační stabilita produktů při ozařování? Mechanismus izomerizace dvojné vazby s použitím jodu. Proč byly zvoleny butylderiváty, byly zkoušeny například hexylderiváty? Student uspokojivě zodpověděl položené dotazy., Dokončená práce s úspěšnou obhajobou