Tez özetleri Astronomi ve Uzay Bilimleri Anabilim Dalı

Conformatıonal Structure of Nocodazole and Analysıs of

Its Experımental Vıbratıonal Spectra
In this thesis study, the stable conformers of nocodazole molecule, which is a neoplastic agent, were investigated by the aid of the theoretical molecular modelling method at room temperature. The molecular mechanics and molecular dynamics calculations have constituted the first step of the conformational study carried out in order to determine the stable conformers. Afterwards, electronic structure calculations were performed at MP2/6-31G(d), B3LYP/6-31G(d), B3LYP/6-311++G(d,p) and B3LYP/cc-pvTZ levels of theory for each of the conformers determined from these preliminary calculations at the low-level theories.
The obtained calculation results have demonstrated that intra-molecular hydrogen bonding interactions significantly restrict the conformational variety of nocodazole and therefore at the free state the molcule has only eight stable conformers at room temperature. According to the same theoretical results, the two of the determined conformers are, by values ranging from 1 to 5 kcal/mol, lower in energy and thus remarkably more stable than the others. The vibrational modes of these two conformers determined to provide the dominant contribution to the recorded experimental vibrational spectra of the molecule, and the associated IR and Raman spectral data were calculated by using the harmonic oscillator approach.
The force field, wavenumbers, IR and Raman intensities calculated in the harmonic oscillator approach at B3LYP/6-31G(d) level of theory were then improved by means of an empirical scaling method, called “SQM FF” in the literature. Besides this, a scaling process (fitting to the experiment) was carried out on the harmonic wavenumbers calculated at B3LYP/6-31G(d), B3LYP/6-311++G(d,p) and B3LYP/cc-pvTZ levels of theory by using the emprical scaling approach referred so as to “the dual scaling factors”. In the light of the obtained improved theoretical vibrational spectral data, a correct assignment of the fundamental bands observed in the room-temperature experimental IR and Raman spectra of the molecule was achieved.

  

YAPICI Berin

Tez Adı : Atomik Vanadyumun 3d³4s4p Konfigürasyonunun Aşırı İnce Yapısının İncelenmesi

Danışman :Prof. Dr. Gönül Başar

Anabilim Dalı : Fizik

Programı : Atom ve Molekül Fiziği

Mezuniyet Yılı : 2013

Tez Savunma Jürisi :Prof. Dr.Gönül Başar

Prof. Dr.Ayşen Özel

Doç. Dr.Elif Akalın

Doç. Dr.Kubilay Balcı

Doç. Dr.Gülay Acar