Fluorescence Dynamics of Monocyclodextrin– and Bis(thiol‐cyclodextrin)–Coumarin C153 Complexes |
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| Authors: | Marianna Gregova Trencanova Dr Eduard Jane Dr Vojtech Szocs Sona Halaszova Dr Monika Jerigova Ludovit Haizer Prof Dusan Velic |
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| Institution: | 1. Department of Physical and Theoretical Chemistry, Comenius University, Mlynska dolina, Bratislava (Slovakia);2. International Laser Center, Ilkovicova 3, Bratislava (Slovakia);3. Institue of Chemistry, Comenius University, Mlynska dolina, Bratislava (Slovakia) |
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| Abstract: | The solvation and confinement of coumarin C153 within supramolecular host/guest complexes based on β‐cyclodextrin (β‐CD) and 6‐deoxy‐6‐thio‐β‐cyclodextrin (β‐CD‐SH) in water are studied by fluorescence spectroscopy. For β‐CD/C153, the 1:1 complex is proposed, and for β‐CD‐SH/C153 both the 1:1 and 2:1 complexes are believed to be formed. The 2:1 β‐CD‐SH/C153 complex has an association constant of 4.2×105 M ?1 and a C153 population of 82 %, which are interestingly high values, indicating that the proposed β‐CD‐SH dimers structure are connected by covalent disulfide bonds; this is supported by mass spectrometry. Solvation related to fast hydrogen‐bond rearrangement as a part of fluorescence relaxation is determined by the ultrafast components of time‐resolved spectroscopy to be 3 and 7 ps for the 1:1 β‐CD/C153 and 2:1 β‐CD‐SH/C153 complexes, respectively. |
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| Keywords: | coumarin C153 cyclodextrins fluorescence supramolecular chemistry thiols |
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