Polyhedral Bismuth Polycations Coordinating Gold(I) with Varied Hapticity in a Homoleptic Heavy‐Metal Cluster

Abstract

Shiny black, air‐sensitive crystals of [Au(Bi 8 ) 2 ](AlCl 4 ) 5 were obtained from the reaction of AuCl, BiCl 3 , and bismuth in the ionic liquid [BMIm]Cl · 4AlCl 3 (BMIm = 1‐ n ‐butyl‐3‐methylimidazolium) at 180 °C. [Au(Bi 8 ) 2 ](AlCl 4 ) 5 crystallizes in the monoclinic space group P 2 1 / n . In the heavy‐metal cluster [Au(Bi 8 ) 2 ] 5+ , two square‐antiprismatic Bi 8 2+ polycations coordinate the gold(I) atom in η 2 ‐ and η 4 ‐mode, respectively. Quantum chemical calculations demonstrate that both Bi 8 2+ polycations involve skeletal electrons for the donor bonding, which causes a widening of Bi–Bi distances compared with those in free Bi 8 2+ .