Eintrag in der Universitätsbibliographie der TU Chemnitz
Volltext zugänglich unter
URN: urn:nbn:de:bsz:ch1-qucosa2-347878
Schnaubelt, Linda
Lang, Heinrich ; Mehring, Michael (Gutachter)
Redox-coupled Spin Transition in Co(2+/3+) Complexes with Triarylamine-substituted Polypyridyl-based Ligands
Kurzfassung in englisch
The present PhD thesis describes the synthesis and characterisation of Co(2+/3+) complexes with triarylamine-substituted polypyridyl-based ligands. A light- or temperature-induced intramolecular electron transfer between the Co and the triarylamine moieties was found in the tri-cationic complexes, which was examined with electrochemical measurements, DFT calculations, optical and dynamic 1H NMR spectroscopy. This process is coupled to a high-spin <--> low-spin transition on the metal. The emphasis of this PhD thesis was the adjustment of a redox equilibrium between the paramagnetic ([Co2+(L+)(L)]3+) and diamagnetic ([Co3+(L)2]3+) formulation (L = triarylaminedecoratedligands) via the electron transfer. The position of this equilibrium is influenced
by the complexes' structure and environment. Constitutional changes in the
ligand topology were performed to modify the electronic properties of the triarylamine substituents and to vary the distance between the redox centres, namely the Co ion and the triarylamine nitrogen atom. If they are located within their van-der-Waals radii, photochemical excitation of the diamagnetic ground state leads to the paramagnetic excited state. A temperature-dependent redox equilibrium was found with an increased distance between the redox centres (d = 8 Å), due to the different entropies of the redox isomers.
| Universität: | Technische Universität Chemnitz | |
| Fakultät: | Fakultät für Naturwissenschaften | |
| Dokumentart: | Dissertation | |
| Betreuer: | Lang, Heinrich | |
| SWD-Schlagwörter: | Triarylamine , Ladungstransfer , Elektrochemie , Spektroelektrochemie , Protonen-NMR-Spektroskopie | |
| Freie Schlagwörter (Englisch): | Cobalt , Triarylamine , Spin Transition , Electron Transfer , Electrochemistry , Spectroelectrochemistry , 1 H NMR Spectroscopy | |
| DDC-Sachgruppe: | Chemie | |
| Sprache: | englisch | |
| Tag der mündlichen Prüfung | 23.07.2019 |
