Search for: All records

The reactivity of Bi_n⁻clusters (n= 2 to 30) with O₂is found to display even-odd alternations. The open-shell even-sized Bi_n⁻clusters are more reactive than the closed-shell odd-sized clusters, except Bi₁₈⁻, which exhibits no observable reactivity toward O₂. We have investigated the structure and bonding of Bi₁₈⁻to understand its remarkable resistance to oxidation. We find that the most stable structure of Bi₁₈⁻consists of two Bi₈cages linked by a Bi₂dimer, where each atom is bonded to three neighboring atoms. Chemical bonding analyses reveal that each Bi uses its three 6pelectrons to form three covalent bonds with its neighbors, resulting in a Bi₁₈⁻cluster without any dangling bonds. We find that the robust Bi₁₈framework along with the totally delocalized unpaired electron is responsible for the surprising inertness of Bi₁₈⁻toward O₂. The Bi₁₈framework is similar to that in Hittorf’s phosphorus, suggesting the possibility to create bismuth nanoclusters with interesting structures and properties.