Live long and phosphor: extending absorptive cross-sections and excited-state lifetimes through benzannulation
| dc.contributor.author | Lozada, Issiah | |
| dc.contributor.examiningcommittee | Schreckenbach, H. Georg (Chemistry) | en_US |
| dc.contributor.examiningcommittee | Davis, Rebecca (Chemistry) | en_US |
| dc.contributor.examiningcommittee | Lin, Francis (Physics) | en_US |
| dc.contributor.supervisor | Herbert, David E. | |
| dc.date.accessioned | 2022-12-20T18:00:15Z | |
| dc.date.available | 2022-12-20T18:00:15Z | |
| dc.date.copyright | 2022-12-18 | |
| dc.date.issued | 2022-12-18 | |
| dc.date.submitted | 2022-12-19T04:10:55Z | en_US |
| dc.degree.discipline | Chemistry | en_US |
| dc.degree.level | Doctor of Philosophy (Ph.D.) | en_US |
| dc.description.abstract | There are several strategies in modifying the electronic structure of molecules. Functional group modification is perhaps the most used approach. In this thesis, I explore a different approach through the expansion of ligand π-systems by fusing benzene rings (benzannulation). Benzannulation introduces physicochemical and photophysical changes in molecules without significant changes in the parent framework. In this work, I use computational analysis to investigate the impact of benzo-fused pyridines, quinoline and phenanthridine. Phenanthridine introduces a lower-lying unoccupied molecular orbital (LUMO) compared with quinoline, red-shifting the absorption spectra of complexes. Combining phenanthridines with π-donor ligands enabled the isolation of iron complexes with panchromatic absorption. In addition, benzannulation enables more efficient mixing between the excited singlet and triplet states facilitating the direct Tn←S0 transition. Interestingly, the luminescent properties of the complexes supported by phenanthridine exhibit blue-shifted emission compared with the quinoline-supported analogues. The enhanced rigidity provided by phenanthridine contributes to the observed higher energy shift. Building on these findings, a series of new phenanthridine-containing ligands and their boron, zinc and platinum complexes were then pursued. Some of these complexes exhibit long-live emissive excited states originating from triplet states. In addition, new phenanthridine precursors bearing water-soluble and surface-anchoring groups were introduced. Finally, the antineoplastic activity of Pt(II) complexes supported by N^N^O ligands was explored, leading to the discovery of complexes with enhanced cytotoxicity compared with cisplatin both in dark and upon exposure to light. | en_US |
| dc.description.note | February 2023 | en_US |
| dc.identifier.uri | http://hdl.handle.net/1993/37017 | |
| dc.language.iso | eng | en_US |
| dc.rights | open access | en_US |
| dc.subject | Benzannulation | en_US |
| dc.subject | Ligand design | en_US |
| dc.subject | Coordination Complexes | en_US |
| dc.subject | Inorganic | en_US |
| dc.subject | Photophysics | en_US |
| dc.title | Live long and phosphor: extending absorptive cross-sections and excited-state lifetimes through benzannulation | en_US |
| dc.type | doctoral thesis | en_US |
| local.subject.manitoba | no | en_US |