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

Redox reaction of the monovalent Rh 2 (CO) 4 Cl 2 and Bi n n − ( n = 2, 3) from K 5 Bi 4 in ethylenediamine ( en ) solution produced the decabismuthide-hexarhodium dianion [Rh@Bi 10 (RhCO) 5 ] 2− ( 1a ) wherein a novel Bi 10 -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. The largest polybismuth heteroanion[Rh@Bi 10 (Rh-CO) 5 ] 2 4− , yielded by the redox reaction of K 5 Bi 4 and Rh 2 (CO) 4 Cl 2 in en solution of 2,2,2-cryptand. wherein the reduced oligomeric Rh@(Rh-CO) 5 unit is covalently and datively bonded to the Bi 10 -bowl.