Understanding complex supramolecular landscapes: non-covalent macrocyclization equilibria examined by fluorescence resonance energy transfer
| Autor: | Marina Blanco-Lomas, Elham Fadaei, David Serrano-Molina, David González-Rodríguez, María José Mayoral, Jorge Camacho-García, Eva Magdalena-Estirado |
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| Přispěvatelé: | UAM. Departamento de Química Orgánica, UAM. Instituto de Investigación Avanzada en Ciencias Químicas (IAdChem), Nanostructured Molecular Systems and Materials Group |
| Rok vydání: | 2018 |
| Předmět: |
Excitation energy
Circular dichroism 010405 organic chemistry Chemistry Intermolecular force Supramolecular chemistry Molecular self-assembled system Cooperativity Watson–Crick H-bonding pairs Química General Chemistry Analytical techniques 010402 general chemistry 01 natural sciences Fluorescence Fluorescence spectroscopy 0104 chemical sciences chemistry.chemical_compound Thermodynamic Förster resonance energy transfer Monomer Chemical physics Macrocyclization reaction |
| Zdroj: | Biblos-e Archivo. Repositorio Institucional de la UAM instname Chemical Science |
| ISSN: | 2041-6539 2041-6520 |
| DOI: | 10.1039/c8sc03229g |
| Popis: | Energy transfer between FRET pairs is employed herein to reveal novel intermolecular interactions between self-assembled macrocycles, built via Watson–Crick pairing between complementary dinucleosides, and mononucleoside competitors. As molecular self-assembled systems increase in complexity, due to a large number of participating entities and/or the establishment of multiple competing equilibria, their full understanding becomes likewise more complicated, and the use of diverse analytical techniques that can afford complementary information is required. We demonstrate in this work that resonance excitation energy transfer phenomena, measured by fluorescence spectroscopy in combination with other optical spectroscopies, can be a valuable tool to obtain supplementary thermodynamic data about complex supramolecular landscapes that other methods fail to provide. In particular, noncovalent macrocyclization processes of lipophilic dinucleosides are studied here by setting up a competition between intra- and intermolecular association processes of Watson–Crick H-bonding pairs. Multiwavelength analysis of the monomer emission changes allowed us to determine cyclotetramerization constants and to quantify chelate cooperativity, which was confirmed to be substantially larger for the G-C than for the A-U pair. Furthermore, when bithiophene-BODIPY donor–acceptor energy transfer probes are employed in these competition experiments, fluorescence and circular dichroism spectroscopy measurements in different regions of the visible spectrum additionally reveal intermolecular interactions occurring simultaneously at both sides of the macrocyclization reaction: the cyclic product, acting as a host for the competitor, and the monomer reactant, ultimately leading to macrocycle denaturation. |
| Databáze: | OpenAIRE |
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