National Repository of Grey Literature 16 records found  1 - 10next  jump to record: Search took 0.01 seconds. 
Preparation of diketopyrrolopyrrole-based (DPP) polymers for organic electronics
Solanský, Lukáš ; Veselý, Dominik (referee) ; Cigánek, Martin (advisor)
The modern world is burdened by dependence on electricity and problems with its production. A very advantageous way to gain electricity is through photovoltaics. However, the production of silicon solar cells is demanding and expensive with a high impact on the environment. For this reason, there is an effort to switch to solar cells based on organic semiconductors. These include, for example, polymers based on diketopyrrolopyrrole (DPP). The theoretical part of this thesis deals with organic electronics, conductive polymers and DPP-based polymers, their properties and applications. It further describes the most common synthetic approaches to DPP-based polymers. The experimental part of this final work describes the preparation of intermediates necessary for the synthesis of the resulting DPP-based polymers using Stille reaction. The thiophene derivative of DPP was N,N'­alkylated and subsequently brominated. Furthermore, organotin intermediates were prepared, which together with the dibrominated DPP derivative participate in the polymerization.
Study of effect of side chains of organic semiconductors for bioelectronic applications
Ivanová, Lucia ; Cigánek, Martin (referee) ; Krajčovič, Jozef (advisor)
Organic bioelectronics is a relatively young but perspective science discipline that introduces the applicability of organic electronic materials in bioelectronic devices. The promising outlook for using these applications ranges from improving the quality of the disabled people's life to the development of artificial intelligence. The theoretical part describes the essential properties of semiconducting polymers for the utilization in bioelectronics and, moreover, it presents a way of improving these properties by the proper implementation of the side chains. It deals with the possibility of optimizing the biomimetic properties of conjugated polymers by using bio-inspired molecules as peripheral chains, specifically nucleic bases. The nucleobase groups introduced onto the polymer chain thus provide the synthetic molecules with the ability of self-assembly and recognition of each other. The second part of the thesis focuses on the modification of the adenine molecule, with the preparation of the key intermediate for Stille coupling. Subsequent cross-coupling reaction results in the extension of the adenine’s -conjugated system with the thiophene molecule.
Preparation and study of the reactivity of a new series of N, N'-substituted diketopyrrolopyrrole (DPP) for organic photonics
Cigánek, Martin ; Vyňuchal, Jan (referee) ; Krajčovič, Jozef (advisor)
Currently, the major trend is the development of materials that could be used for transformation of solar energy into electrical energy. Organic photovoltaics studies this area of interest and especially in recent years increasingly tries to put functional materials of organic origin into practice. These materials belong to a group of "high performance pigments" due to their exceptional and relatively stable properties. One of the most important molecules are the diketopyrrolopyrroles (DPP) derivatives. The theoretical part of this bachelor work describes the organic electronics and photonics, DPP derivatives, various synthetic routes of DPP, properties of particular DPP derivatives and the dependence of their properties on the used substituents. There are described separation and analytical methods most commonly used in organic synthesis too. The experimental part describes the preparation of the backbone DPP containing thiophene units. The following are the modifications of DPP backbones with N,N‘-alkylation and N,N‘-arylation.
Modification of Organic High Performance Pigments for Applications in Organic Electronics
Cigánek, Martin ; Imramovský, Aleš (referee) ; Vyňuchal, Jan (referee) ; Krajčovič, Jozef (advisor)
Dizertační práce pojednává o studiu, syntéze a chemické derivatizaci molekul spadajících do skupiny organických vysoce výkonných pigmentů a jejich potenciálním uplatnění v oblastech organické elektroniky. Teoretická část práce je zaměřena na nejnovější trendy v dané oblasti, a to jak z aplikačního potenciálu konkrétních derivátů, tak z pohledu syntetických možností a jejich strukturálních derivatizací. V experimentální části je pak podrobně popsána příprava pestré škály intermediátů a výsledných produktů, zahrnujících deriváty diketopyrrolopyrrolů (DPP), benzodifuranonu (BDF), epindolidionu (EP), naphthyridinedionu (NTD) a polymeru na bázi thiofenu (PT). Celkově bylo nasyntetizováno 103 molekul, přičemž 49 tvořily výsledné produkty, z nichž 27 bylo zcela nových, dosud nepublikovaných. Hlavním motivem derivatizace molekul pigmentů je zde inkorporace derivátů adamantanu do finálních struktur. V další části práce jsou blíže diskutovány jednotlivé chemické modifikace vedoucí k výsledným produktům. Na sérii N,N'-; N,O'- a O,O'-substituovaných derivátů DPP je popsána komplexní studie vlivu charakteru alkylových řetězců a také pozice jejich navázání v molekule DPP, a to nejen na selektivitu reakce, ale rovněž na optické i termické vlastnosti syntetizovaných produktů.
The synthesis and study of new derivatives of diketopyrrolopyrroles for organic electronics
Cigánek, Martin ; Maier, Lukáš (referee) ; Krajčovič, Jozef (advisor)
This diploma thesis describes organic pigments of diketopyrrolopyrroles (DDPs) possessing properties applicable in attractive and perspective areas of organic electronics and photonics. The modification of the DPP skeleton was performed by nucleophilic substitution by various alkyl chains and 5 series of DPP derivatives were prepared. The regioselectivity of N-alkylation and also the photophysical properties of the prepared derivatives were studied. A key product of this work is the N,N'-ethyladamantyl derivative of DPP, which exhibited ambipolar characteristic with excellent electron mobility of 0.2 cm2 V–1 s–1. Further, the -conjugation of the above-mentioned DPP derivative was extended by 1 and 2 thiophene units at positions 3,6 and the effect of this modification on optical properties of the resulting derivatives was investigated. A new modified N,N'-unsubstituted DPP derivative was also prepared. The last point of this thesis was the study of the incorporation of formyl functional groups into the skeleton of key N,N'-ethyladamantyl DPP derivative.
Nature-inspired macro cyclic systems for bioorganic applications
Prekopová, Terézia ; Cigánek, Martin (referee) ; Krajčovič, Jozef (advisor)
The bachelor thesis deals with nature-inspired macrocyclic compounds and their possible use in organic bioelectronics. The theoretical part of this bachelor thesis introduces semiconductor materials in organic bioelectronics and provides a general overview of selected classes of macrocyclic compounds currently occurring. It includes their history, properties, reactivity and use in various industries. An important point of this part are cyclodextrins, which are characterized by their high biocompatibility and affinity for a wide range of guests depending on the structure of the cyclodextrin. They are capable of molecular recognition to form inclusion complexes with guest particles. The work also deals with chemical modifications of cyclodextrins in order to improve selected physicochemical properties and practical applications of cyclodextrins. The experimental part consists of the synthesis, purification and characterization of key macrocyclic -cyclodextrin derivatives selectively modified at position 6 of one glucopyranose unit for the synthesis and study of advanced supramolecular structures for potential applications in organic bioelectronics.
New derivatives of diketopyrrolo[2,3-f]indole (DPIs) for organic electronics
Šípek, Jiří ; Richtár, Jan (referee) ; Cigánek, Martin (advisor)
This bachelor's thesis deals with semiconducting materials based on diketopyrroloindoles, their preparation and possible applications. In the theoretical part of the thesis, a current overview of the issues of organic electronics and photonics is presented, and technologies using the potential of organic molecules to behave as semiconductors capable of transmitting electrical energy are presented. A brief history highlights important milestones for organic conductive molecules and polymers, including important categories of high performance organic pigments and dyes such as diketopyrroloindoles (DPI). In other parts of the work, the synthetic approaches known so far in the preparation of DPI themselves are summarized, with a focus on their thiophene analogues and related derivatives. In the experimental part, the preparation of the basic molecule of the DPI skeleton is described. Finally, three derivatives differing in the character of the aliphatic side chain from a series of branched, linear and bulky substituents prepared by means of N,N'alkylation reactions are presented.
Utilisation of the double bond in the synthesis of new types of molecular photoswitches applicable in biological systems
Bartošová, Aneta ; Ivanová, Lucia (referee) ; Cigánek, Martin (advisor)
This bachelor thesis deals with the synthesis and characterization of new advanced organic molecules with the utilization of the structure motive of the double bond for purposes of application as molecular photoswitches. The theoretical part of the thesis introduces the types of molecules, their characterization and the comparison of fundamental isomers. In the next, section, the mechanisms of isomerization are presented, synthesis via cross-coupling reaction, comparison of advantages and disadvantages of methods and possible application of these molecules in medicine, biological systems and in material chemistry. In the experimental part of the thesis, the multistep synthesis of two final derivatives with an imine bond is described, which can possibly secure the application of these original materials like molecular photoswitches.
Bio-inspired organic molecules for photodynamic therapy
Švarcová, Nikola ; Cigánek, Martin (referee) ; Krajčovič, Jozef (advisor)
Photodynamic therapy is a treatment method using the clinical application of photosensitisers for alternative treatment of oncological and inflammatory diseases. Using photosensitisers, substances with absorption properties, is a crucial element for the effective therapy process. Flavins can serve as photosensitisers in photodynamic therapy thanks to their conjugated system. The proposed bachelor thesis is focused on preparing of a novel, riboflavin-inspired flavin derivative. The structural isomers of riboflavin, alloxazines, provide simple synthetic modification for material properties enhancement. The theoretical part deals with the principle and mechanism of photodynamic therapy, modern trends in medical applications, limitations, benefits and essential elements for the effective therapy process. Consequently, the possibility of flavin derivatives potential use as infrared-absorbing photosensitisers is considered. The experimental part aims to prepare the intermediates and final precursors, 1,3-dialkylated uracil and acenaphthene-based 1,2-diketone. Verified synthetic paths described in the thesis provided high yields of the prepared intermediates and final precursors. Thus, the approaches will be utilized in the following synthetic studies to prepare the acenaphthene flavins series.
Synthesis of polymer precursors based on isosorbide
Šichnárek, Vojtěch ; Cigánek, Martin (referee) ; Figalla, Silvestr (advisor)
The theoretical part of the thesis deals with the description of reduced hexitols, methods of isosorbide production and its application purpose in polymer materials. It includes a description of the glucose dehydration process, the influence of reaction conditions and the catalysis of the isosorbide production, the polymerization of isosorbide monomers and their properties. The experimental part of the work is focused on the optimization of isosorbide’s laboratory synthesis‘ reaction conditions, the description of its chemical modification to polymerizable isosorbide derivatives and the physical-chemical characterization of the produced molecules. The synthesis of isosorbide is monitored by LC-MS, the product is subjected to various refining methods and a detailed structural characterization. GC was chosen for the monitoring of the preparation of isosorbide dimethacrylate and structural verification of the diester was confirmed by FT-IR, MS and NMR. The physical-chemical characterization of the prepared isosorbide dimethacrylate consists of the description of its rheological properties in mixture with a commercial methacrylated oil and the study of the reactivity of the monomers by DSC. The mixture of methacrylated oil and isosorbide dimethacrylate was used to prepare polymer thermosets which were analyzed by thermo-mechanical methods such as DMA, bending and TGA. The highest isosorbide conversion achieved value of 81.9 % after 5 hours, and it reached 94,1 % for isosorbide dimethacrylate after 8 hours. According to the results, isosorbide dimethacrylate possesses the abilty to reduce the shear viscosity of polymerizable precursors and to increase the glass transition temperature and crosslinking densities of polymer thermoset.

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