Interaction of gas molecules with cyclo[N]carbon: Size dependence and atomic doping modulation

The unique electronic properties of cyclo[N]carbon have attracted considerable attention due to their potential applications in gas storage and sensing technologies. This work employed density functional theory (DFT) and DLPNO-CCSD(T) to investigate the molecular adsorption characteristics of cyclo[N]carbon (N = 12, 14, and 16) with various gas molecules. It is interesting that the adsorption strength of cyclo[N]carbon for gases increases as the size of cyclo[N]carbon increases, with polar molecules demonstrating stronger interactions than nonpolar ones. Local energy decomposition analysis at the high-end DLPNO-CCSD(T) level of theory reveals that London dispersion forces significantly contribute to adsorption stability. By incorporating the Mg2 dimer in two-layer C16, a stable Mg22+@(C16)22- complex is formed, and the encapsulation of divalent cations considerably enhances the gas molecule adsorption performance. This study provides valuable insights into the adsorption properties of cyclo[N]carbon, which could be crucial for advancements in next-generation molecular devices.