Dimeric polybismuth heteroanion of [Rh@Bi₁₀(RhCO)₅]^2- constructed using Bi₁₀-bowl and square pyramidal Rh@(Rh-CO)₅

Redox reaction of the monovalent Rh-2(CO)(4)Cl(2 )and Bi-n(n-) (n = 2, 3) from K5Bi4 in ethylenediamine (en) solution produced the decabismuthide-hexarhodium dianion [Rh@Bi-10(RhCO)(5)](2-) (1a) wherein a novel Bi10-bowl was constructed from oxidized 2Bi(3)/2Bi(2) open triangles/dimers, which was stabilized by strong bonding to a reduced Rh@(RhCO)(5) square pyramid. Two 1a dianons are held together by weak interactions (van der Waals forces and spatial resistance) to form a dimer [Rh@Bi-10(RhCO)(5)](2)(4-) (1). The structure and bonding of the novel polybismuthide heteroanion 1 are discussed.