Influence of cyclodextrin size on fluorescence quenching in conjugated polyrotaxanes by methyl viologen in aqueous solution
Poly(4,4′-diphenylenevinylene) rotaxanes and [2]rotaxanes with α-, β-, γ-cyclodextrin macrocycles were synthesised and their sensitivities to fluorescence quenching by methyl viologen in aqueous solution were determined, relative to uninsulated analogues. Stern-Volmer analysis revealed that the fluo...
| Main Authors: | , , , , , |
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| Format: | Journal article |
| Language: | English |
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2009
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| _version_ | 1797070281664102400 |
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| author | Oddy, F Brovelli, S Stone, M Klotz, E Cacialli, F Anderson, H |
| author_facet | Oddy, F Brovelli, S Stone, M Klotz, E Cacialli, F Anderson, H |
| author_sort | Oddy, F |
| collection | OXFORD |
| description | Poly(4,4′-diphenylenevinylene) rotaxanes and [2]rotaxanes with α-, β-, γ-cyclodextrin macrocycles were synthesised and their sensitivities to fluorescence quenching by methyl viologen in aqueous solution were determined, relative to uninsulated analogues. Stern-Volmer analysis revealed that the fluorescence quenching response of polyrotaxanes is strongly dependent on the diameter of the cyclodextrins. Polyrotaxanes, composed of the smaller diameter α- or β-cyclodextrins, are the least easily quenched, with Stern-Volmer constants about two orders of magnitude smaller than from the wider γ-cyclodextrin polyrotaxane and the uninsulated polymer. Time-resolved photoluminescence results demonstrate the crucial role of interchain aggregation on the sensitivity to fluorescence quenchers. The materials with the highest Stern-Volmer constants exhibit the most biexponential photoluminescence decay, which is indicative of aggregation, and the emission spectra of solutions containing methyl viologen resemble the early-time emission spectra (0-3 ns after excitation) of the unquenched samples. The results show that the threaded α-cyclodextrin is effective in preventing aggregation, and in hindering fluorescence quenching, even when only a small fraction of the conjugated polymer is encapsulated. This conclusion is relevant to the application of these materials in optoelectonic devices, such as light-emitting diodes, where it is essential to prevent luminescence quenching without hindering charge transport. © 2009 The Royal Society of Chemistry. |
| first_indexed | 2024-03-06T22:36:34Z |
| format | Journal article |
| id | oxford-uuid:5a19a402-f458-48cc-8186-bce693ba0d62 |
| institution | University of Oxford |
| language | English |
| last_indexed | 2024-03-06T22:36:34Z |
| publishDate | 2009 |
| record_format | dspace |
| spelling | oxford-uuid:5a19a402-f458-48cc-8186-bce693ba0d622022-03-26T17:13:45ZInfluence of cyclodextrin size on fluorescence quenching in conjugated polyrotaxanes by methyl viologen in aqueous solutionJournal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:5a19a402-f458-48cc-8186-bce693ba0d62EnglishSymplectic Elements at Oxford2009Oddy, FBrovelli, SStone, MKlotz, ECacialli, FAnderson, HPoly(4,4′-diphenylenevinylene) rotaxanes and [2]rotaxanes with α-, β-, γ-cyclodextrin macrocycles were synthesised and their sensitivities to fluorescence quenching by methyl viologen in aqueous solution were determined, relative to uninsulated analogues. Stern-Volmer analysis revealed that the fluorescence quenching response of polyrotaxanes is strongly dependent on the diameter of the cyclodextrins. Polyrotaxanes, composed of the smaller diameter α- or β-cyclodextrins, are the least easily quenched, with Stern-Volmer constants about two orders of magnitude smaller than from the wider γ-cyclodextrin polyrotaxane and the uninsulated polymer. Time-resolved photoluminescence results demonstrate the crucial role of interchain aggregation on the sensitivity to fluorescence quenchers. The materials with the highest Stern-Volmer constants exhibit the most biexponential photoluminescence decay, which is indicative of aggregation, and the emission spectra of solutions containing methyl viologen resemble the early-time emission spectra (0-3 ns after excitation) of the unquenched samples. The results show that the threaded α-cyclodextrin is effective in preventing aggregation, and in hindering fluorescence quenching, even when only a small fraction of the conjugated polymer is encapsulated. This conclusion is relevant to the application of these materials in optoelectonic devices, such as light-emitting diodes, where it is essential to prevent luminescence quenching without hindering charge transport. © 2009 The Royal Society of Chemistry. |
| spellingShingle | Oddy, F Brovelli, S Stone, M Klotz, E Cacialli, F Anderson, H Influence of cyclodextrin size on fluorescence quenching in conjugated polyrotaxanes by methyl viologen in aqueous solution |
| title | Influence of cyclodextrin size on fluorescence quenching in conjugated polyrotaxanes by methyl viologen in aqueous solution |
| title_full | Influence of cyclodextrin size on fluorescence quenching in conjugated polyrotaxanes by methyl viologen in aqueous solution |
| title_fullStr | Influence of cyclodextrin size on fluorescence quenching in conjugated polyrotaxanes by methyl viologen in aqueous solution |
| title_full_unstemmed | Influence of cyclodextrin size on fluorescence quenching in conjugated polyrotaxanes by methyl viologen in aqueous solution |
| title_short | Influence of cyclodextrin size on fluorescence quenching in conjugated polyrotaxanes by methyl viologen in aqueous solution |
| title_sort | influence of cyclodextrin size on fluorescence quenching in conjugated polyrotaxanes by methyl viologen in aqueous solution |
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