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Authors: Wang, Di
Title: Reversible Stimuli Responsive Radicals and Their EPR Spectroscopic Characterization
Online publication date: 4-Feb-2019
Language: english
Abstract: My thesis is about the synthesis of organic radicals with external stimuli-responsive properties, characterization and analysis of spin and magnetic properties with the measurements of electron paramagnetic resonance (EPR) and simulations of density functional calculations (DFT). In this work I discuss different external stimuli factors to interact with the spin systems: e.g. temperature, reduction and or oxidation, and photo stimulation. Different characterizations, especially EPR spectroscopy, were used to detect the transitions or switch of the whole radical systems. Several interesting changes of spin properties were found during the processes, like hyperfine splitting of spin species and the spin coupling interactions between radicals. Some vital transitions of spin species can have bright potentials in the future applications. The introduction of organic radical systems with stimuli responsive properties, their possible applications and the motivations of this thesis are outlined in chapter 1. Then this is followed by a brief description of EPR spectroscopy in 2nd chapter. In chapter 3, I summarized the solvent and temperature effects on flexibly bridged bis(nitronyl nitroxides). Chapter 4 deals with the oxidation of donors like phenothiazine and phenoxazine which are combined with a conjugated nitronyl nitroxide radical unit, which I synthesized. In addition, EPR spectroscopy is successfully used to investigate the mechanism of the whole photo induced reaction by trapping and analysis of the radical intermediate species existing during the whole processes, which is described in chapter 5. In the last chapter, I studied the oxidation and reduction of a spiro bridged bishexabenzocoronene. It turned out that this new molecule cannot be described just by connection of HBCs but new non degenerate HOMOs and LUMOs are formed.
DDC: 540 Chemie
540 Chemistry and allied sciences
Institution: Johannes Gutenberg-Universität Mainz
Department: FB 09 Chemie, Pharmazie u. Geowissensch.
Place: Mainz
URN: urn:nbn:de:hebis:77-diss-1000025947
Version: Original work
Publication type: Dissertation
License: in Copyright
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Extent: VII, 164 Seiten
Appears in collections:JGU-Publikationen

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