Isolation and Characterization of a Bismuth(II) Radical

摘要

More than 80years 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(NONAr)Cl (NONAr=[O(SiMe2NAr)(2)](2-); Ar=2,6-iPr(2)C(6)H(3)) with magnesium affords the Bi-II radical Bi-.(NONAr). 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.