Vrednovanje teorijskih alata za modeliranje apsorpcijskih i fluorescencijskih spektara

master's thesis

• Title (english): Assessing theoretical tools for modeling absorption and fluorescence spectra
• Author: Tomislav Rožić
• Mentor: Nađa Došlić (mentor)
• Committee member: Tomica Hrenar (predsjednik povjerenstva)
• Committee member: Nađa Došlić (član povjerenstva)
• Committee member: Ivan Kodrin (član povjerenstva)
• Committee member: Vladimir Stilinović (član povjerenstva)
• Committee member: Tajana Begović (član povjerenstva)
• Granter: University of Zagreb; Faculty of Science; (Department of Chemistry); Zagreb
• Defense date and country: 2020-09-30, Croatia
• Scientific / art field, discipline and subdiscipline: NATURAL SCIENCES; Chemistry

Abstract

Uspješnim modeliranjem spektara apsorpcije i/ili fluorescencije dovodimo se u položaj iz
kojeg možemo relativno pouzdano donositi zaključke o tom sustavu – jer poznajemo model
na temelju kojeg je spektar generiran. Nas je zanimala skupina tercijarnih amina kod kojih je
opisana tzv. netradicionalna intrinzična luminiscencija. Cilj je bio razjasniti uzrok
luminiscencije kod dva takva sustava – DABCO-a i ABCO-a usporedbom računanih spektara
s dostupnim eksperimentalnim spektrima visoke rezolucije. Unatoč simetrijskim efektima i
korištenju harmoničke aproksimacije, dobiveno je vrlo dobro slaganje izračunanih
apsorpcijskih i fluorescencijskih spektara DABCO-a s eksperimentom, čime smo povezali
njegovu netradicionalnu luminiscenciju s procesima apsorpcije i fluorescencije te
Rydbergovom prirodom njihovih pobuđenih elektronskih stanja. Nadalje su izračunani i
optički spektri "tradicionalnog" pirazina - prototipske fotokemijske molekule s
delokaliziranim π-elektronskim sustavom. Dobiveni rezultati poslužit će nam za vrednovanje
dostupnih teorijskih alata za modeliranje optičkih spektara molekula netrivijalne složenosti.

Abstract (english)

Successfully modeling absorption and/or fluorescence spectra allows us to make more reliable
conclusions about the system since we know the base model on which the spectrum was
generated. We were interested in a group of tertiary amines in which the phenomenon of nontraditional
luminescence was observed. Our goal was to clarify the cause of the luminescence
in two such molecules – DABCO and ABCO by comparing the computed spectra with
available high-resolution experimental ones. Despite symmetry effects and staying within the
harmonic approximation, we have achieved a good agreement with experiment which allowed
us to link its non-traditional luminescence with absorption and fluorescence to and from
excited states of Rydberg character. Furthermore, we calculated the optical spectra of
“traditional” pyrazine, a prototype photochemical molecule with a delocalized π-electron
system. The obtained results will also serve as a review of the available tools for modeling
optical spectra for molecules of non-trivial complexity.

• Keywords: netradicionalna luminiscencija; apsorpcijski spektar; fluorescencijski spektar
• Keywords (english): nontraditional luminescence; absorption spectrum; fluorescence spectrum
• Language: croatian
• URN:NBN: urn:nbn:hr:217:332602
• Study programme: Title: Graduate university studies in chemistry; specializations in: Research programme; Course: Research programme; Study programme type: university; Study level: graduate; Academic / professional title: magistar/magistra kemije (magistar/magistra kemije)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access; Embargo expiration date: 2021-10-01
• Created on: 2020-10-15 12:48:53