Stable Cubic Phosphorus‐Containing Radicals

Stable, deep‐blue neutral radicals [(Me3SiN)P(μ3‐NtBu)3{μ3‐Li(thf)}3X] (X=Br, I) with distorted cubic structures are obtained by the oxidation of [{Li3[P(NtBu)3(NSiMe3)]}2] with halogens in THF (see picture). The cubes comprise the radical dianion [P(NtBu)3(NSiMe3)].2−, two Li+ ions, and a molecule of LiX. Solvation in very dilute THF solution releases (thf)3LiX and generates the cyclic radical monoanion [(Me3SiN)(tBuN)P(μ‐NtBu)2Li(thf)2].−.