Photogenerated Triplet States in Supramolecular Porphyrin Ladder Assemblies: An EPR Study
Introducing bridging ligands such as DABCO to solutions of linear zinc porphyrin oligomers has previously been shown to lead to the formation of ladder-type assemblies in which the single porphyrin units in each strand adopt a predominantly co-planar conformation. Here, we employ transient Electron...
| Main Authors: | , , , , |
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| Format: | Journal article |
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Royal Society of Chemistry
2016
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| _version_ | 1826276114862964736 |
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| author | Richert, S Peeks, M Tait, C Anderson, H Timmel, C |
| author_facet | Richert, S Peeks, M Tait, C Anderson, H Timmel, C |
| author_sort | Richert, S |
| collection | OXFORD |
| description | Introducing bridging ligands such as DABCO to solutions of linear zinc porphyrin oligomers has previously been shown to lead to the formation of ladder-type assemblies in which the single porphyrin units in each strand adopt a predominantly co-planar conformation. Here, we employ transient Electron Paramagnetic Resonance (EPR) to study photogenerated triplet states of these complexes in frozen solution with a particular focus on the extent of spin delocalisation. We make use of two different techniques: (i) the zero-field splitting parameters D and E are determined using transient continuous wave (cw) EPR spectroscopy and (ii) the hyperfine coupling constants which directly reveal the extent of spin delocalisation are quantified by orientation-selective proton Electron Nuclear DOuble Resonance (ENDOR) spectroscopy. It is found that ladder formation does not encourage triplet state delocalisation either across the bridging ligand DABCO or along the individual porphyrin units despite their co-planar conformation, a structure previously shown to allow increased electronic delocalisation. |
| first_indexed | 2024-03-06T23:09:07Z |
| format | Journal article |
| id | oxford-uuid:64dd177f-389a-473a-ae84-278acc67f05a |
| institution | University of Oxford |
| last_indexed | 2024-03-06T23:09:07Z |
| publishDate | 2016 |
| publisher | Royal Society of Chemistry |
| record_format | dspace |
| spelling | oxford-uuid:64dd177f-389a-473a-ae84-278acc67f05a2022-03-26T18:21:40ZPhotogenerated Triplet States in Supramolecular Porphyrin Ladder Assemblies: An EPR StudyJournal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:64dd177f-389a-473a-ae84-278acc67f05aSymplectic Elements at OxfordRoyal Society of Chemistry2016Richert, SPeeks, MTait, CAnderson, HTimmel, CIntroducing bridging ligands such as DABCO to solutions of linear zinc porphyrin oligomers has previously been shown to lead to the formation of ladder-type assemblies in which the single porphyrin units in each strand adopt a predominantly co-planar conformation. Here, we employ transient Electron Paramagnetic Resonance (EPR) to study photogenerated triplet states of these complexes in frozen solution with a particular focus on the extent of spin delocalisation. We make use of two different techniques: (i) the zero-field splitting parameters D and E are determined using transient continuous wave (cw) EPR spectroscopy and (ii) the hyperfine coupling constants which directly reveal the extent of spin delocalisation are quantified by orientation-selective proton Electron Nuclear DOuble Resonance (ENDOR) spectroscopy. It is found that ladder formation does not encourage triplet state delocalisation either across the bridging ligand DABCO or along the individual porphyrin units despite their co-planar conformation, a structure previously shown to allow increased electronic delocalisation. |
| spellingShingle | Richert, S Peeks, M Tait, C Anderson, H Timmel, C Photogenerated Triplet States in Supramolecular Porphyrin Ladder Assemblies: An EPR Study |
| title | Photogenerated Triplet States in Supramolecular Porphyrin Ladder Assemblies: An EPR Study |
| title_full | Photogenerated Triplet States in Supramolecular Porphyrin Ladder Assemblies: An EPR Study |
| title_fullStr | Photogenerated Triplet States in Supramolecular Porphyrin Ladder Assemblies: An EPR Study |
| title_full_unstemmed | Photogenerated Triplet States in Supramolecular Porphyrin Ladder Assemblies: An EPR Study |
| title_short | Photogenerated Triplet States in Supramolecular Porphyrin Ladder Assemblies: An EPR Study |
| title_sort | photogenerated triplet states in supramolecular porphyrin ladder assemblies an epr study |
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