| Institution: | 1. College of Environmental Science and Engineering, Hunan University, Changsha, 410082 P. R. China
School of Chemistry and Biochemistry and Center for Organic Photonics and Electronics, Georgia Institute of Technology, Atlanta, GA 30332-0400 USA;2. Department of Chemistry and Biochemistry, The University of Arizona, Tucson, Arizona 85721-0008 USA |
| Abstract: | Many efforts are currently devoted to improving the stability and crystallinity of imine-based two-dimensional (2D) covalent organic frameworks (COFs) given their wide range of potential applications. The variation in the relative orientations of the imine bonds has been found to be a critical factor that impacts the stacking of the 2D COF layers, leads to the formation of isomer structures, and influences the crystallinity of the final product. Most investigations to date have focused only on the structural properties, while the role of the imine orientations on the electronic properties has not been studied systematically. Here, we explore this effect by examining how the electronic band structures, electronic couplings, and effective masses evolve when considering four isomeric structures of an imine-linked tetraphenyl-pyrene naphthalene-diimide COF. Our results provide an understanding of the impact of the imine orientations and how they need to be controlled to realize COF inter-layer stackings that can lead to efficient cross-plane electron transport. They can be used to guide the design and synthesis of imine-based COFs for applications where charge transport needs to be optimized. |
