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

Abstract

Reaction of at ethered triamine ligand with Bi-(NMe 2 ) 3 gives aBitriamide,for which aBi I electronic structure is shown to be most appropriate.T he T-shaped geometry at bismuth provides the first structural model for edge inversion in bismuthines and the only example of aplanar geometry for pnictogen triamides.A nalogous phosphorus compounds exhibit ad istorted pyramidal geometry because of different BiÀNa nd PÀNb ond polarities.A lthough considerable Bi I character is indicated for the title Bi triamide,i te xhibits reactivity similar to Bi III electrophiles,a nd expresses either avacant or afilled porbital at Bi, as evidenced by coordination of either pyridine N-oxideo rW (CO) 5 .T he product of the former shows evidence of coordination-induced oxidation state change at bismuth. Scheme 1. Synthesis of low-oxidation-state p-block complexes by either external reductants or redox-active ligands.

Periodicity in Structure, Bonding, and Reactivity for P-Block Complexes of a Geometry-Constraining Triamide Ligand

“…All three p-orbitals are engaged in EÀN s bonding in the bent case. [8] The LUMO in the bent geometry is EÀN s*i nn ature and appears trans to the central EÀNb ond as expected for the + +III oxidation state of pnictogen amides. Consequently,i nt he planarg eometry,a vacant p-orbital remains availablep erpendicular to the molecular plane at the central element and it is the LUMO in each case.…”

“…[8] Lithiation of the triamide ligand N 3 H 3 ,f ollowed by reaction with one molar equivalent of AsCl 3 gave compound 2 which was isolated as ac rystalline solid in 55 %y ield. [8] Lithiation of the triamide ligand N 3 H 3 ,f ollowed by reaction with one molar equivalent of AsCl 3 gave compound 2 which was isolated as ac rystalline solid in 55 %y ield.…”

“…[3] Radosevichh as done pioneeringw ork in evolvingn ew geometry constrained main-group compounds includings ystems featuring constrained P III triamidest hat exhibit catalytic activity (C). [8] Applications of tridentate-ligand-bound planarB i I compoundsi nc atalysis have now startedt oa ppear in work by Cornella, [9] following the comprehensive investigations by Breunig, Raţ, Nikonov,a nd Dostàlo fm onoanionic pnictogen N-C-N chelates. [5] Moving beyond phosphorus, tethered triamidel igands have been used by Dutton and Martin to achievea na pproximately T-shaped planargeometry at boron (F) [6] and by Greb to achieveseverely distorted tetrahedral arrangements at silicon that demonstrate noveld imerizationm odes (G).…”

Reversible C=C Bond Activation by an Intramolecularly Coordinated Antimony(I) Compound

“…reported on a very interesting bismuth T‐shaped triamide with a planar ground state. This compound exhibited a redox‐confused bismuth(I/III) situation and may thus serve as Bi I ‐donor for a W(CO) 5 fragment, but also as a Bi III source . Recently, Cornella et al.…”

“…This compound exhibited ar edox-confused bismuth(I/III) situation andm ay thus serve as Bi I -donor foraW(CO) 5 fragment, but also as aB i III source. [12] Recently,C ornella et al showedt hat the N,C,N-chelated bismuth(I) compound (Figure1A) wasa ble to serve as a catalystf or the transfer hydrogenation of azo compounds and suggested that the catalytic cycle involves the Bi I ÀBi III redox couple. [13] We have used similarh eavy pnictogen(I) compounds as ligands for transition metals [14] including those in which the antimony atom bridges two Pd atoms [15] ( Figure 1B).…”