20.500.12556/DKUM-81562 Vibracijski in rotacijski prehodi enostavnih molekul magistrsko delo Vibrational and rotational transitions of simple molecules V magistrskem delu obravnavamo rotacijske in vibracijske prehode molekul. Molekulsko dinamiko bomo opisali z analitiˇcnimi metodami, zato se bomo omejili na dovolj preproste molekule z dobro definirano simetrijo. Pravilnost izraˇcunov bomo preverili z obiˇcajnimi raˇcunalniˇskimi orodji, ki se v kemiji uporabljajo za prikaz in opis molekulske dinamike. Namen magisterskega dela je bilo preveriti, do kam lahko pridemo z analitiˇcnim pristopom pri obravnavi infrardeˇce spektroskopije manjˇsih molekul z enostavnimi simetrijami. Izkazalo se je, da je to izredno zahteven postopek, kateri zahteva tako znanje kemije kot tudi teorije grup. V tem delu smo predstavili ter uporabili nastavke za izraˇcun najpomembnej ˇsih parametrov, kateri vplivajo na intenzitete v infrardeˇcem spektru, t.j. spinska statistiˇcna uteˇz za dane irreducibilne specije spinske valovne funkcije ter energije rotacij oz. vibracij ˇzeljene molekule. S pomoˇcjo ter dveh parametrov smo pri dani temperaturi zapisali Boltzmannovo enaˇcbo infrardeˇcega spektra ter s prikazali odsek le-tega. Primera vode ter CHF3 sta bila skrbno izbrana zaradi razliˇcnih simetrijskih lastnosti (asimetriˇcni vs. simetriˇcni rotor, 2 protona vs. 3 protoni itd.) ter zaradi relativne enostavnosti izraˇcunov. V zakljuˇcku smo predstavili ˇse dodatne aspekte analitiˇcne analize, katerim bi se lahko posluˇzili t.j. spremembe simetrije molekule ob substituciji tipa atoma, teˇzave z relativistiˇcnim nadaljevanjem ter karakterizacija elektronske valovne funkcije preko LCAO ansazt-a. The purpose of this master’s thesis was to verify to what extent an analytical approach in dealing with infrared spectroscopy of smaller molecules with simple symmetries is possible. This has proven to be an extremely demanding process that requires both knowledge of chemistry and group theory. In this work we presented and used group theoretical and quantum mechanical methods to calculate the most important parameters which determine the intensities in the infrared spectrum, i.e. spin statistical weights for given irreducible representations of spin wave function and the rotational/vibrational energy of the desired molecule. Using these two parameters, we wrote down the Boltzmann equation of the infrared spectrum at a given temperature and showed a section of it. The examples of water and CHF3 are carefully chosen because of the different symmetry properties of both molecules (asymmetric vs. symmetric rotor, 2 protons versus 3 protons, etc.) and because of the relative simplicity of the calculations. In the conclusion cahpter, we presented additional aspects of analytical analysis that could be used, i.e. changes in the symmetry of the molecule upon substitution of the atom type, problems with relativistic continuation, and the characterization of electron wave functions via the LCAO ansazt. Molekulska dinamika vibracije in rotacije molekul molekulska simetrija infrardeˇca spektroskopija resonanˇcne frekvence raˇcunski program Gaussian IR molecular spectroscopy irreducible representation rotations and vibrations of molecules nuclear spin. true true false [M. Orel] Slovenski jezik Angleški jezik Magistrsko delo/naloga 2022-04-15 06:39:12 2022-05-20 12:09:18 2022-08-10 00:36:25 0000-00-00 00:00:00 2022 0 Maribor 0 Maribor 1 spletni vir (1 datoteka PDF (XVIII, 100 f.)) 0000-00-00 NiDoloceno NiDoloceno NiDoloceno 0000-00-00 0000-00-00 0000-00-00 544.15:544.174.2(043.2) 108944899 MAG_Orel_Matic_2022.pdf MAG_Orel_Matic_2022.pdf 1 1BA7FDC0C0F1AC5487FAB549955B2261 3d4337d2b5e107647a550d43b2b3b45f9a741a41d7c67028c00572539e252a0f 2eaea6c4-d819-11ec-9202-00155d000105 20.500.12556/dkum/de08df53-bcfe-4872-87ce-b7e779a9fb3c https://dk.um.si/Dokument.php?lang=slv&id=157961 Fakulteta za kemijo in kemijsko tehnologijo 0 0 0