Synthesis and Characterization of Monomeric Triarylbismuthine Oxide

The synthesis and isolation of a bismuth-based analogue of the venerable triphenylphosphine oxide (Ph₃PO) has remained a chimera to synthetic chemists for many years, due to its predicted high reactivity and instability. Through the hydrolysis of a cationic fluorotriarylbismuthonium(V) salt, we report here the isolation of unique hydroxytriarylbismuth(V) complexes, which served as precursor for the formation of the elusive monomeric triarylbismuthine oxide Dipp₃Bi=O. Combined spectroscopic, crystallographic and computational studies provided insight into the bonding situation of the first monomeric triorganobismuth oxide complex. The Dipp₃Bi=O and Mes₃BiO⋅LiBAr^F complex exhibits O-atom transfer reactivity, an uncommon reactivity feature for Ar₃Pn=O.