Bis(bismuth)toluene Inverted-Sandwich Complex Supported by Aminetris(phenoxide) Ligands

The reaction of bismuth amides or alkoxides with phenolic ligand precursors yields Bi complexes of aminetris(phenoxide)s, one of which was characterized by X-ray crystallography, revealing monomeric Bi units of the tetradentate NO₃ ligand further associated via a symmetrical toluene bridge into a bis(bismuth)toluene inverted-sandwich complex. Synthesis of the analogous Sb complex suggests a markedly different geometric and electronic environment at the metal center, as evidenced by the solid-state molecular structure. Density functional theory calculations of the sandwich bismuth arene complex indicate the presence of a weak σ*−2π interaction.