A Redox-Confused Bismuth(I/III) Triamide with a T-Shaped Planar Ground State

Reaction of a tethered triamine ligand with Bi(NMe₂ )₃ gives a Bi triamide, for which a Bi^I electronic structure is shown to be most appropriate. The T-shaped geometry at bismuth provides the first structural model for edge inversion in bismuthines and the only example of a planar geometry for pnictogen triamides. Analogous phosphorus compounds exhibit a distorted pyramidal geometry because of different Bi-N and P-N bond polarities. Although considerable Bi^I character is indicated for the title Bi triamide, it exhibits reactivity similar to Bi^III electrophiles, and expresses either a vacant or a filled p orbital at Bi, as evidenced by coordination of either pyridine N-oxide or W(CO)₅ . The product of the former shows evidence of coordination-induced oxidation state change at bismuth.