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Göteborgs universitets publikationer

Far-infrared conformer-specific signatures of small aromatic molecules of biological importance

Författare och institution:
Vasyl Yatsyna (Institutionen för fysik (GU))
ISBN:
978-91-639-1823-0
Antal sidor:
75
Publikationstyp:
Licentiatavhandling
Förlag:
University of Gothenburg
Förlagsort:
Göteborg
Publiceringsår:
2016
Språk:
engelska
Datum för examination:
2016-09-29
Tidpunkt för examination:
13:15
Lokal:
PJ Salen, Örigo Norra, Fysikgården 2B, Göteborgs universitet
Opponent:
Donatas Zigmantas
Sammanfattning (abstract):
Our understanding of many biological processes requires knowledge about biomolecular structure and weak intra- and intermolecular interactions (e.g. hydrogen bonding). Both molecular structure and weak interactions can be directly studied by far-infrared (or THz) spectroscopy, which probes low-frequency molecular vibrations. In this thesis I present the results of experimental and theoretical investigations of far-infrared vibrations in small aromatic molecules of biological relevance. To enable a direct comparison with theory, far-infrared spectroscopy was performed in the gas phase with a conformer-selective IR-UV ion-dip technique. The far-infrared spectra of molecules containing a peptide (-CO-NH-) link revealed that the low-frequency Amide IV-VI vibrations are highly sensitive to the structure of the peptide moiety, the molecular backbone, and the neighboring intra- and intermolecular hydrogen bonds. The study of far-infrared spectra of phenol derivatives identified vibrations that allow direct probing of strength of hydrogen-bonding interaction, and a size of a ring closed by the hydrogen bond. Furthermore, benchmarking theory against the experimental data identified advantages and disadvantages of conventional frequency calculations for the far-infrared region performed with ab initio and density functional theory. For example, the conventional approaches were not able to reproduce strongly anharmonic vibrations such as amino-inversion in aminophenol. Instead, a double-minimum potential model was used for this vibration, and successfully described the experimental spectra of aminophenol. The results presented in this thesis can assist the interpretation of far-infrared spectra of more complex biomolecules, pushing forward low-frequency vibrational spectroscopy for efficient structural analysis and the studies of weak interactions.
Ämne (baseras på Högskoleverkets indelning av forskningsämnen):
NATURVETENSKAP ->
Fysik ->
Atom- och molekylfysik och optik ->
Molekylfysik
NATURVETENSKAP ->
Fysik ->
Atom- och molekylfysik och optik ->
Kemisk fysik
Postens nummer:
240652
Posten skapad:
2016-08-23 13:27
Posten ändrad:
2016-08-23 13:38

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