Isolation and Characterization of a Bismuth(II) Radical

Abstract 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(SiMe 2 NAr) 2 ] 2− ; Ar=2,6‐ i Pr 2 C 6 H 3 ) 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.