title: Stability of B12 (CN)12 (2-) : Implications for Lithium and Magnesium Ion Batteries.
abstract: Multiply charged negative ions are seldom stable in the gas phase. Electrostatic repulsion leads either to autodetachment of electrons or fragmentation of the parent ion. With a binding energy of the second electron at 0.9 eV, B12 H12 (2-) is a classic example of a stable dianion. It is shown here that ligand substitution can lead to unusually stable multiply charged anions. For example, dodecacyanododecaborate, B12 (CN)12 (2-) , created by substituting H by CN is found to be highly stable with the second electron bound by 5.3 eV, which is six times larger than that in the B12 H12 (2-) . Equally important is the observation that CB11 (CN)12 (2-) , which contains one electron more than needed to satisfy the Wade-Mingos rule, is also stable with its second electron bound by 1.1 eV, while CB11 H12 (2-) is unstable. The ability to stabilize multiply charged anions in the gas phase by ligand manipulation opens a new door for multiply charged species with potential applications as halogen-free electrolytes in ion batteries.
authors.affiliation: Department of Physics, School of Science, Beijing Jiaotong University, China.|Physics Department, Virginia Commonwealth University, USA.
authors.forename: Hongmin
authors.initials: H
authors.lastname: Zhao
authors.affiliation: Physics Department, Virginia Commonwealth University, USA. jzhou2@vcu.edu.
authors.forename: Jian
authors.initials: J
authors.lastname: Zhou
authors.affiliation: Physics Department, Virginia Commonwealth University, USA. pjena@vcu.edu.
authors.forename: Puru
authors.initials: P
authors.lastname: Jena
keywords: cluster compounds; cyanoborate cluster; electronic structure; ion battery; ligand effects