Differentiating the mechanism of self-assembly in supramolecular polymers through computation
Autor: | Will R. Henderson, Ronald K. Castellano, Sundaram Balasubramanian, Divya B. Korlepara |
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Rok vydání: | 2019 |
Předmět: |
Materials science
010402 general chemistry 01 natural sciences Oligomer Catalysis chemistry.chemical_compound symbols.namesake Materials Chemistry Spectroscopy chemistry.chemical_classification Isodesmic reaction 010405 organic chemistry Metals and Alloys General Chemistry Polymer 0104 chemical sciences Surfaces Coatings and Films Electronic Optical and Magnetic Materials Gibbs free energy Supramolecular polymers Monomer chemistry Chemical physics Ceramics and Composites symbols Self-assembly |
Zdroj: | Chemical communications (Cambridge, England). 55(26) |
ISSN: | 1364-548X |
Popis: | The mechanism by which monomers in solution, beyond a certain concentration or below a certain temperature, self-assemble to form one dimensional supramolecular polymers determines much of the bulk properties of the polymer. The two distinct pathways of assembly, namely isodesmic and cooperative, can be experimentally identified using spectroscopy and in simulations via a determination of the dependence of the association constant on the oligomer size. Employing large scale free energy calculations, we have been able to show the independence of the free energy change of oligomerization on size in the self-assembly of a [2.2]paracyclophane-tetracarboxamide ([2.2]pCpTA) derivative ([2.2]pCpTA-hex), which is experimentally shown to follow the isodesmic pathway. In contrast, simulations show the free energy change in the case of benzene-1,3,5-tricarboxamide (BTA) to depend on the oligomer size which is a signature of its cooperative nature of self-assembly. These observations are rationalized through the development of a macrodipole moment in BTA oligomers and lack thereof in the [2.2]pCpTA system. |
Databáze: | OpenAIRE |
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