Computational Prediction of Stacking Mode in Conductive Two-Dimensional Metal-Organic Frameworks: An Exploration of Chemical and Electrical Property Changes

Abstract

Conductive two-dimensional metal-organic frameworks(2DMOFs) have attracted interest as they induce strong charge delocalizationand improve charge carrier mobility and concentration. However, characterizingtheir stacking mode depends on expensive and time-consuming experimentalmeasurements. Here, we construct a potential energy surface (PES)map database for 36 2D MOFs using density functional theory (DFT)for the experimentally synthesized and non-synthesized 2D MOFs topredict their stacking mode. The DFT PES results successfully predictthe experimentally synthesized stacking mode with an accuracy of 92.9%and explain the coexistence mechanism of dual stacking modes in asingle compound. Furthermore, we analyze the chemical (i.e., host-guestinteraction) and electrical (i.e., electronic structure) propertychanges affected by stacking mode. The DFT results show that the host-guestinteraction can be enhanced by the transition from AA to AB stacking,taking H2S gas as a case study. The electronic band structurecalculation confirms that as AB stacking displacement increases, thein-plane charge transport pathway is reduced while the out-of-planecharge transport pathway is maintained or even increased. These resultsindicate that there is a trade-off between chemical and electricalproperties in accordance with the stacking mode.