University of Central Florida
Ghazvini Zadeh, Ebrahim.
Investigating New Guaiazulenes and Diketopyrropyrroles for Photonic Applications.
Degree: 2015, University of Central Florida
?-Conjugated systems have been the focus of study in recent years in order to understand their charge transport and optical properties for use in organic electronic devices, fluorescence bioimaging, sensors, and 3D optical data storage (ODS), among others. As a result, several molecular building blocks have been designed, allowing new frontiers to be realized. While various successful building blocks have been fine-tuned at both the electronic and molecular structure level to provide advanced photophysical and optoelectronic characteristics, the azulene framework has been under-appreciated despite its unique electronic and optical properties. Among several attributes, azulenes are vibrant blue naturally occurring hydrocarbons that exhibit large dipolar character, coupled with stimuli-responsive behavior in acidic environments. Additionally, the non-toxic nature and the accompanying eco-friendly feature of some azulenes, namely guaiazulene, may set the stage to further explore a more "green" route towards photonic and conductive materials. The first part of this dissertation focuses on exploiting guaiazulene as a natural building block for the synthesis of chromophores with varying stimuli-responsiveness. Results described in Chapter 1 show that extending the conjugation of guaiazulene through its seven-membered ring methyl group with aromatic substituents dramatically impacts the optical properties of the guaiazulenium carbocation. Study of these ?–stabilized tropilium ions enabled establishing photophysical structure-property trends for guaiazulene-terminated ?-conjugated analogs under acidic conditions, including absorption, emission, quantum yield, and optical band gap patterns. These results were exploited in the design of a photosensitive polymeric system with potential application in the field of three dimensional (3D) optical data storage (ODS). Chapter 2 describes the use of guaiazulene reactive sites (C-3 and C-4 methyl group) to generate a series of cyclopenta[ef]heptalenes that exhibit strong stimuli-responsive behavior. The approach presents a versatile route that allows for various substrates to be incorporated into the resulting cyclopenta[ef]heptalenes, especially after optimization that led to devising a one-pot reaction toward such tricyclic systems. Examining the UV-vis absorption profiles in neutral and acidic media showed that the extension of conjugation at C(4) of the cyclopenta[ef]heptalene skeleton results in longer absorption maxima and smaller optical energy gaps. Additionally, it was concluded that these systems act as sensitizers of a UV-activated (< 300 nm) photoacid generator (PAG), via intermolecular photoinduced electron transfer (PeT), upon which the PAG undergoes photodecomposition resulting in the generation of acid. In a related study, the guaiazulene methyl group at C-4 was employed to study the linear and nonlinear optical properties of 4-styrylguaiazulenes, having the same ?–donor with varying ?-spacer. It was realized that the conjugation length correlates with the extent of…
Advisors/Committee Members: Belfield, Kevin.
Subjects/Keywords: Optical data storage; guaiazulene; azulene; bioimaging; renewable resources; photoacid generator; stimuli responsiveness; cyclopenta[ef]heptalenes; two photon absorption; stimulated emission depletion; fluorescence microscopy; Chemistry; <; p>; Dissertations, Academic – Sciences; Sciences – Dissertations, Academic<; /p>
to Zotero / EndNote / Reference
APA (6th Edition):
Ghazvini Zadeh, E. (2015). Investigating New Guaiazulenes and Diketopyrropyrroles for Photonic Applications. (Doctoral Dissertation). University of Central Florida. Retrieved from https://stars.library.ucf.edu/etd/1485
Chicago Manual of Style (16th Edition):
Ghazvini Zadeh, Ebrahim. “Investigating New Guaiazulenes and Diketopyrropyrroles for Photonic Applications.” 2015. Doctoral Dissertation, University of Central Florida. Accessed July 21, 2019.
MLA Handbook (7th Edition):
Ghazvini Zadeh, Ebrahim. “Investigating New Guaiazulenes and Diketopyrropyrroles for Photonic Applications.” 2015. Web. 21 Jul 2019.
Ghazvini Zadeh E. Investigating New Guaiazulenes and Diketopyrropyrroles for Photonic Applications. [Internet] [Doctoral dissertation]. University of Central Florida; 2015. [cited 2019 Jul 21].
Available from: https://stars.library.ucf.edu/etd/1485.
Council of Science Editors:
Ghazvini Zadeh E. Investigating New Guaiazulenes and Diketopyrropyrroles for Photonic Applications. [Doctoral Dissertation]. University of Central Florida; 2015. Available from: https://stars.library.ucf.edu/etd/1485