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https://elib.belstu.by/handle/123456789/20915
Title: | Free base and protonated form fluorescence of the mixed 5,10,15,20-arylporphyrins |
Authors: | Kruk, M. M. Vershilovskaya, I. V. Ngo, T. Scheblykin, I. G. Dehaen, W. Maes, W. |
Keywords: | порфирины свободные основания протонированные формы молекулярная конформация флуоресценция |
Issue Date: | 2016 |
Publisher: | BSTU |
Citation: | Free base and protonated form fluorescence of the mixed 5,10,15,20-arylporphyrins / M. M. Kruk [et al.] // Proceedings of BSTU. No. 4. – Minsk : BSTU, 2016. – P. 12-15 |
Abstract: | Fluorescence spectra for a series of mixed phenyl-mesityl 5,10,15,20-tetraarylporphyrins – with Mes4, Mes3Ph, Mes2Ph2- trans, Mes2Ph2- cis, MesPh 3 and Ph4 type architecture (Mes – mesityl, Ph – phenyl) – in their free base, mono- and diprotonated form are reported. Substitution of a single mesophenyl group with a sterically more demanding mesityl group is found to be sufficient to provide stabi-lization of the monoprotonated porphyrin species. A decrease in the number of mesityl substituents in the macrocycle leads to a decrease in the fluore scence quantum yield for protonated forms. The pro-gressive replacement of ortho,ortho’-substituted mesityl groups with unhindered phenyls results in the additive pattern of spectral changes for the free base porphyrins, whereas for both protonated species a specific jump at the trans to cis transition is observed, along with a gradual additive pattern before and afterwards. This feature is interpreted as a signature of the transition between the hindered-like and un-hindered-like conformations of the tetrapyrrolic m acrocycles in the protonated forms. These two mo-lecular conformations provide a different interaction of the two one-electron (a1u,eg) and (a2u,eg) configurations, which leads to changes of their contributions into electronic transitions. |
URI: | https://elib.belstu.by/handle/123456789/20915 |
Appears in Collections: | 2016, № 4 |
Files in This Item:
File | Description | Size | Format | |
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Kruk.Free base.pdf | 650.5 kB | Adobe PDF | View/Open |
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