A Stable Anionic Dithiolene Radical

Abstract

Sulfurization of anionic N-heterocyclic dicarbene, [: C{[N(2,6-Pr i 2 C 6 H 3 )] 2 CHCLi}] n ( 2 ), with elemental sulfur (in a 1:2 ratio) in Et 2 O at low temperature gives 3 by inserting two sulfur atoms into the Li–C (i.e., C2 and C4) bonds in polymeric 2 . Further reaction of 3 with 2 equiv of elemental sulfur in THF affords 4 • via unexpected C–H bond activation, which represents the first anionic dithiolene radical to be structurally characterized in the solid state. Alternatively, 4 • may also be synthesized directly by reaction of 1 with sulfur (in a 1:4 ratio) in THF. Reaction of 4 • with GeCl 2 ·dioxane gives an anionic germanium(IV)–bis(dithiolene) complex ( 5 ). The nature of the bonding in 4 • and 5 was probed by experimental and theoretical methods.