Supramolecular Copolymers: Structure and Composition Revealed by Theoretical Modeling
| Autor: | Anja R. A. Palmans, Ghislaine Vantomme, Huub M. M. ten Eikelder, E. W. Meijer, Albert J. Markvoort, Miguel García-Iglesias, Anindita Das |
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| Přispěvatelé: | Universidad de Cantabria, Macro-Organic Chemistry, Computational Biology, Macromolecular and Organic Chemistry, Institute for Complex Molecular Systems |
| Rok vydání: | 2017 |
| Předmět: |
Circular dichroism
Stereochemistry Supramolecular chemistry 010402 general chemistry 01 natural sciences Biochemistry Catalysis Article chemistry.chemical_compound Colloid and Surface Chemistry Copolymerization Side chain Copolymer Theoretical models Alkyl chemistry.chemical_classification 010405 organic chemistry Monomers General Chemistry Polymer 0104 chemical sciences Crystallography Monomer chemistry Covalent bond Mixtures Thermodynamics |
| Zdroj: | Journal of the American Chemical Society Journal of the American Chemical Society, 2017, 139(20), 7036-7044 UCrea Repositorio Abierto de la Universidad de Cantabria Universidad de Cantabria (UC) Journal of the American Chemical Society, 139(20), 7036-7044. American Chemical Society |
| ISSN: | 1520-5126 0002-7863 |
| Popis: | Supramolecular copolymers, non-covalent analogues of synthetic copolymers, constitute a new and promising class of polymers. In contrast to their covalent counterparts, the details of their mechanism of formation, as well as the factors determining their composition and length, are still poorly understood. Here, the supramolecular copolymerization between two slightly structurally different benzene-1,3,5-tricarboxamide (BTA) monomers functionalized with either oligodimethylsiloxane (oDMSi) or alkyl side chains is unraveled by combining experimental and theoretical approaches. By applying the “sergeant-and-soldiers” approach using circular dichroism (CD) experiments, we are able to obtain detailed insights into the structure and composition of these supramolecular copolymers. Moreover, we observe an unexpected chiral induction upon mixing two independently CD-silent solutions of the achiral (soldier) and chiral (sergeant) monomers. We find that the subtle differences in the chemical structure of the two monomers impact their homopolymerization mechanism: whereas alkyl-BTAs cooperatively self-assemble, oDMSi-BTAs self-assemble in an isodesmic manner. The effect of these mechanistic differences in the supramolecular copolymerization process is investigated as a function of the composition of the two monomers and explicitly rationalized by mathematical modeling. The results show that, at low fractions of oDMSi-BTA sergeants (25 mol%), the isodesmic assembly of the increasing amounts of sergeant becomes more dominant, and different species start to coexist in the copolymerization process. The analysis of the experimental data with a newly developed theoretical model allows us to quantify the thermodynamic parameters, the distribution of different species, and the compositions and stack lengths of the formed supramolecular copolymers existing at various feed ratios of the two monomers. This work was financially supported by The Netherlands Organization for Scientific Research (NWO-TOP PUNT Grant 10018944) and the Dutch Ministry of Education, Culture and Science (Gravity Program 024.001.035). |
| Databáze: | OpenAIRE |
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