Isolation and Characterization of a Bismuth(II) Radical.

Angewandte Chemie (International ed. in English)

PubMedID: 26215838

Schwamm RJ, Harmer JR, Lein M, Fitchett CM, Granville S, Coles MP. Isolation and Characterization of a Bismuth(II) Radical. Angew Chem Int Ed Engl. 2015;.
More than 80 years after Paneth's report of dimethyl bismuth, the first monomeric Bi(II) radical that is stable in the solid state has been isolated and characterized. Reduction of the diamidobismuth(III) chloride Bi(NON(Ar) )Cl (NON(Ar) =[O(SiMe2 NAr)2 ](2-) ; Ar=2,6-iPr2 C6 H3 ) with magnesium affords the Bi(II) radical (. ) Bi(NON(Ar) ). X-ray crystallographic measurements are consistent with a two-coordinate bismuth in the +2 oxidation state with no short intermolecular contacts, and solid-state SQUID magnetic measurements indicate a paramagnetic compound with a single unpaired electron. EPR and density functional calculations show a metal-centered radical with >90?% spin density in a p-type orbital on bismuth.