Dimeric polybismuth heteroanion of [Rh@Bi 10 (RhCO) 5 ] 2- constructed using Bi 10 -bowl and square pyramidal Rh@(Rh-CO) 5 .

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