At the molecular mechanic level, the capability of a set of 24 molecular cage-like structures, the spherophanes, to store hydrogen molecules has been studied. Two main factors have been found to govern their storage c...At the molecular mechanic level, the capability of a set of 24 molecular cage-like structures, the spherophanes, to store hydrogen molecules has been studied. Two main factors have been found to govern their storage capacity： the volume of their cavity and the potential energy barriers at the different openings at the surface of the cage. Calculations have shown that 13H2 molecules could be stored inside the thiaspherophane, Th4S, whose mean radius is 10A and the resulting complex （H2）I3@Th4S is found to be stable. The results show that it would be very difficult to store more than 2H2 inside the smallest spherophane, Sp4, whose mean radius is 7.7A. The mean intermolecular distance Hz-Hz and the mean bond length H-H have been found to decrease when the number of imprisoned hydrogen molecules increases. It has also been found that the encapsulated H2 molecules form clusters of different symmetries on which the formation energy depends strongly. Even with 13H2 molecules inside Th4S, the weight percentage is still small, 2.57%. The largest obtained wt% is 3.22% in the case of Th5S（CH3）10.展开更多
文摘At the molecular mechanic level, the capability of a set of 24 molecular cage-like structures, the spherophanes, to store hydrogen molecules has been studied. Two main factors have been found to govern their storage capacity： the volume of their cavity and the potential energy barriers at the different openings at the surface of the cage. Calculations have shown that 13H2 molecules could be stored inside the thiaspherophane, Th4S, whose mean radius is 10A and the resulting complex （H2）I3@Th4S is found to be stable. The results show that it would be very difficult to store more than 2H2 inside the smallest spherophane, Sp4, whose mean radius is 7.7A. The mean intermolecular distance Hz-Hz and the mean bond length H-H have been found to decrease when the number of imprisoned hydrogen molecules increases. It has also been found that the encapsulated H2 molecules form clusters of different symmetries on which the formation energy depends strongly. Even with 13H2 molecules inside Th4S, the weight percentage is still small, 2.57%. The largest obtained wt% is 3.22% in the case of Th5S（CH3）10.
