Atomic hydrogen transmission through five-membered carbon ring by the mechanism of non-adiabatic tunneling

A novel usage of the non-adiabatic effects is proposed. In this proposal, atomic hydrogen penetrates through a five-membered carbon ring with the help of the non-adiabatic tunneling phenomenon. The cyclopentadienyl radical (C5H5) and pentaboron-substituted corannulenyl radical (C15H10B5) are used to illustrate the mechanism. To demonstrate the proposal, first principles calculations are performed for the non-adiabatic dynamics on potential energy surfaces determined by multi-reference configuration interaction method. The results show that the non-adiabatic transitions between the ground and excited states essentially control the hydrogen atom transmission through the five-membered ring of a pentaboron-substituted corannulenyl radical. It is found that the transmission occurs more than once out of four incidences when an appropriate initial wave packet is chosen. The phenomenon can be interpreted in terms of the Zhu-Nakamura semiclassical theory of non-adiabatic transitions.