A remarkable mixture of germanium with phosphorus and arsenic atoms making stable pentagonal hetero-prisms [M@Ge5E5]+, E = P, As and M = Fe, Ru, Os

摘要

A pentagonal hetero-prismatic structural motif was found for singly transition metal doped M@Ge _(5) E _(5) ~(+) clusters, where the transition metal atom is located at the centre of a (5/5) Ge _(5) E _(5) prism in which Ge is mixed with either P or As atoms. Structural characterization indicates that each (5/5) Ge _(5) E _(5) prism is established by joining of two Ge _(3) E _(2) and Ge _(2) E _(3) strings in a prismatic fashion rather than two Ge _(5) and E _(5) strings. Each string results from a remarkable mixture of Ge and E atoms and contains only one E–E connection due to the fact that Ge–E bonds are much stronger than E–E connections. From the donor–acceptor perspective, the Ge _(5) E _(5) tube donates electrons to the M center, which behaves as an acceptor. NBO atomic charge and ELI_D analyses demonstrate such electrostatic interactions of the M dopant with a Ge _(5) E _(5) ~(+) tube which likely induce thermodynamic stability for the resulting M@Ge _(5) E _(5) ~(+) cluster. CMO analysis illustrates that the conventional 18 electron count is recovered in the M@Ge _(5) E _(5) ~(+) cations.