Bismuth(III) Complex of the [S4]•– Radical Anion: Dimer Formation via Pancake Bonds

Reaction of bismuth(II) compounds with sulfur gives mixtures of [Bi(NON R )] 2 (μ 2 -S n ) (NON R = [O(SiMe 2 NR) 2 ] 2– ). Examples for n = 1 and 3 have been crystallographically verified for R = 2,6- i Pr 2 C 6 H 3 (Dipp) and R = t Bu, and the pentasulfide ( n = 5) for R = Dipp. The corresponding product from reaction with the new Bi(II) radical Bi(NON Ar‡ ) • (Ar ‡ = C 6 H 2 (CHPh 2 ) 2 - t Bu-2,6,4) exists as the dimer [Bi(NON Ar‡ )(S 4 )] 2, with π*(SOMO)−π*(SOMO) interactions linking the sulfur chains through trans -antarafacial pancake bonds.