Encapsulation of Hydrogen Molecules in C50 Fullerene: An ab Initio Study of Structural, Energetic, and Electronic Properties of H2@C50 and 2H2@C50 Complexes

摘要

Various DFT functionals, including those containing long-range interactions and dispersion, together with HF and MP2 theoretical methods, were used to identify the number of H_(2) molecules that can be encapsulated inside a C_(50) cage. It is demonstrated that the 2H_(2)@C_(50) complex is thermodynamically unstable based on its positive complexation energy. Some discrepancies, however, were found with respect to the stability of the H_(2)@C_(50) complex. Indeed, SVWN5, PBEPBE, MP2, B2PLYP, and B2PLYPD calculations confirmed that the H_(2)@C_(50) complex is thermodynamically stable, while HF, BP86, B3LYP, BHandHLYP, LC–wPBE, CAM–B3LYP, and wB97XD showed that this complex is thermodynamically unstable. Nevertheless, examination of strain and dispersion energies further supported the fact that one H_(2) molecule can indeed be encapsulated inside the C_(50) cage. Other factors, such as the host–guest interactions and bond dissociation energy, were analyzed and discussed.