Total scattering reveals the hidden stacking disorder in a 2D covalent organic framework
| Autor: | Maxwell W. Terban, Robert E. Dinnebier, Bettina V. Lotsch, Sebastian Bette, Frederik Haase, A. Putz |
|---|---|
| Rok vydání: | 2020 |
| Předmět: |
Life sciences
biology Crystallographic point group Materials science Scattering Stacking Pair distribution function 02 engineering and technology General Chemistry 010402 general chemistry 021001 nanoscience & nanotechnology 01 natural sciences Symmetry (physics) 0104 chemical sciences law.invention Chemistry Chemical physics law ddc:570 Crystallization 0210 nano-technology Surface states Covalent organic framework |
| Zdroj: | Chemical Science Chemical science, 11 (47), 12593–12878 'Chemical Science ', vol: 11, pages: 12647-12654 (2020) |
| ISSN: | 2041-6520 2041-6539 |
| DOI: | 10.1039/d0sc03048a |
| Popis: | Interactions between extended π-systems are often invoked as the main driving force for stacking and crystallization of 2D organic polymers. In covalent organic frameworks (COFs), the stacking strongly influences properties such as the accessibility of functional sites, pore geometry, and surface states, but the exact nature of the interlayer interactions is mostly elusive. The stacking mode is often identified as eclipsed based on observed high symmetry diffraction patterns. However, as pointed out by various studies, the energetics of eclipsed stacking are not favorable and offset stacking is preferred. This work presents lower and higher apparent symmetry modifications of the imine-linked TTI-COF prepared through high- and low-temperature reactions. Through local structure investigation by pair distribution function analysis and simulations of stacking disorder, we observe random local layer offsets in the low temperature modification. We show that while stacking disorder can be easily overlooked due to the apparent crystallographic symmetry of these materials, total scattering methods can help clarify this information and suggest that defective local structures could be much more prevalent in COFs than previously thought. A detailed analysis of the local structure helps to improve the search for and design of highly porous tailor-made materials. With total scattering methods and stacking fault simulations, we observe previously predicted random local layer offsets in a COF, which are typically disguised by the apparent crystallographic symmetry but strongly influence properties. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|