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Molecular modelling - Structure and Properties of carbene-based catalyst
Kulovaná, Eva ; Zmrzlý, Martin (oponent) ; Richtera, Lukáš (vedoucí práce)
Molecular modelling enables to predict behaviour of the new compounds and helps to interpret experimental data. The objective of our study was the prediction of selected properties of polymerization catalysts based on carbenes, the prediction of their structures and spectral characteristics. To confirm the behaviour of carbenes and their precursors based on chlorides selected characteristics of a molecule were studied. The visualization of selected molecular orbitals and electrostatic potential-mapped electron density surface was made. Subsequently, bond distances and bond angles of selected imidazole and imidazoline compounds and from them prepared “free” carbenes were obtained by using computer programs. Data of structural similar compounds, which have been already characterized, were obtained from CCDC (Cambridge Crystallographic Data Centre) and were compared with our calculated data. Infrared (IR) and Raman spectra of the imidazole salt and the infrared spectrum of the appropriate carbene were measured. The spectra measured were compared with predicted spectra.
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Molecular modelling - Structure and Properties of carbene-based catalyst
Kulovaná, Eva ; Hermanová, Soňa (oponent) ; Richtera, Lukáš (vedoucí práce)
By using molecular modelling it is possible to predict the behaviour of new compounds and to help interpreting of the experimental data. The objective of the thesis was the prediction of selected properties of polymerization catalysts based on carbenes, the prediction of their structures and spectral characteristics and the study of the mechanism of the ring-opening polymerization of lactide. To confirm the behaviour of carbenes and their precursors based on chlorides selected characteristics of a molecule were studied. The calculation of selected molecular orbitals and electrostatic potential maps was made. Subsequently, bond distances and bond angles of selected imidazole and imidazoline compounds, “free” carbenes and their possible hydrolysis products were obtained by using computer programs. Data of structural similar compounds, which have already been characterized, were obtained from CCDC (Cambridge Crystallographic Data Centre) and were compared with the calculated data. Infrared and Raman spectra of the imidazole salt and the infrared spectrum of the appropriate carbene were measured. The measured spectra were compared with the predicted ones. For the better spectra interpretation the spectra of possible hydrolysis products were calculated. Subsequently, the mechanism of the ring-opening polymerization of lactide was investigated. Based on calculated energies of stationary points the novel mechanism of polymerization was suggested.
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Convergence of the embedding scheme
Hofierka, Jaroslav ; Klimeš, Jiří (vedoucí práce) ; Čížek, Martin (oponent)
Výpočet presných adsorpčných energií molekúl na povrchoch je neľahká úloha, pretože metódy s dostatočnou presnosťou sú príliš výpočtovo náročné na to, aby sa mohli aplikovať na tieto systémy. Teórie vnorenia predstavujú prirodzené riešenie tohto problému: zameranie výpočtov na malú oblasť a zahrnutie efektov prostredia. V tejto diplomovej práci sa skúma metóda vnorenia a odozva mnoho- elektrónových systémov na adsorbovanú nečistotu. Na tento účel sa používajú dva prístupy: tesná väzba a ab initio. V tesnej väzbe študujeme formalizmus Greenových funkcií a získavame explicitné výrazy pre Greenove funkcie rôznych jedno- a dvojrozmerných modelov. Pomocou tohto formalizmu študujeme kvalitatívne lokálnu hustotu stavov a adsorpčné energie. V druhej časti tejto práce sú použité moderné metódy ab initio na štúdium konvergencie schémy subtraktívneho vnorenia pre adsorpčné energie malých systémov s uzavretou valenčnou vrstvou na dvojrozmernom graféne a hexagonálnom nitride boritom. Účinnosť a použiteľnosť schémy je posudzovaná pre neón a fluorovodík ako adsorbáty. Zistili sme, že skúmaná metóda vnorenia funguje lepšie pre neón v porovnaní s fluorovodíkom, čo možno vysvetliť použitou párovou disperznou korekciou.
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Použitelnost výpočetních metod kvantové chemie pro studium interakcí v biologických systémech
PLAČKOVÁ, Lydie
Teoretická část diplomové práce popisuje ab initio metody v kvantové chemii a semiempirické metody, kterými lze překonat hlavní nevýhody týkající se ab initio metod (náklady, rychlost). Experimentální část byla zaměřena na srovnání výsledků vysoce přesné CCSD(T) metody se současně požívanými semiempirickými metodami (AM1, PM3, PM6 a PM7). Data byla porovnávána převážně na malých modelových systémy s ionty, které tvoří podstatnou část mnoha biologických systémů. Kromě toho byla studována použitelnost semiempirických metod pro popis intra- a intermolekulárních vodíkových vazeb a van der Waalsových interakcí.
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Molecular modelling - Structure and Properties of carbene-based catalyst
Kulovaná, Eva ; Hermanová, Soňa (oponent) ; Richtera, Lukáš (vedoucí práce)
By using molecular modelling it is possible to predict the behaviour of new compounds and to help interpreting of the experimental data. The objective of the thesis was the prediction of selected properties of polymerization catalysts based on carbenes, the prediction of their structures and spectral characteristics and the study of the mechanism of the ring-opening polymerization of lactide. To confirm the behaviour of carbenes and their precursors based on chlorides selected characteristics of a molecule were studied. The calculation of selected molecular orbitals and electrostatic potential maps was made. Subsequently, bond distances and bond angles of selected imidazole and imidazoline compounds, “free” carbenes and their possible hydrolysis products were obtained by using computer programs. Data of structural similar compounds, which have already been characterized, were obtained from CCDC (Cambridge Crystallographic Data Centre) and were compared with the calculated data. Infrared and Raman spectra of the imidazole salt and the infrared spectrum of the appropriate carbene were measured. The measured spectra were compared with the predicted ones. For the better spectra interpretation the spectra of possible hydrolysis products were calculated. Subsequently, the mechanism of the ring-opening polymerization of lactide was investigated. Based on calculated energies of stationary points the novel mechanism of polymerization was suggested.
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Molekulové modelování - struktura a vlastnosti lanthanidocenů
Šik, Václav ; Zmrzlý, Martin (oponent) ; Richtera, Lukáš (vedoucí práce)
Molekulové modelování umožňuje předpovídat chování nových látek a napomáhá při jinak obtížné interpretaci experimentálních dat. Byla provedena vizualizace vybraných molekulových orbitalů a map elektrostatických potenciálů a elektronových hustot. Následně pomocí počítačových programů byly získány teoretické vazebné délky a úhly. Z těchto dat můžeme vyvodit predikci struktur a následné vyvození chování molekul a jejich využití při syntéze polymerů. Díky katalýze lanthanodicenových komplexů mohou vznikat biodegradovatelné látky, které by mohly mít uplatnění v biomedicíně. Data strukturně podobných, již charakterizovaných sloučenin, byla získána z CCDC (Cambridge Crystallographic Data Centre) a následně konfrontována s námi vypočítanými daty.
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Molecular modelling - Structure and Properties of carbene-based catalyst
Kulovaná, Eva ; Zmrzlý, Martin (oponent) ; Richtera, Lukáš (vedoucí práce)
Molecular modelling enables to predict behaviour of the new compounds and helps to interpret experimental data. The objective of our study was the prediction of selected properties of polymerization catalysts based on carbenes, the prediction of their structures and spectral characteristics. To confirm the behaviour of carbenes and their precursors based on chlorides selected characteristics of a molecule were studied. The visualization of selected molecular orbitals and electrostatic potential-mapped electron density surface was made. Subsequently, bond distances and bond angles of selected imidazole and imidazoline compounds and from them prepared “free” carbenes were obtained by using computer programs. Data of structural similar compounds, which have been already characterized, were obtained from CCDC (Cambridge Crystallographic Data Centre) and were compared with our calculated data. Infrared (IR) and Raman spectra of the imidazole salt and the infrared spectrum of the appropriate carbene were measured. The spectra measured were compared with predicted spectra.
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