Zinc-Containing Radical Anions via Single Electron Transfer to Donor-Acceptor Adducts.

Abstract

Reactions of [Cp*2 Fe] with the Lewis acid [Zn(C6 F5 )2 ] in the presence of [(PhC(S)S)2 ], 9,10-phenanthrenedione or 4,5-pyrenedione yield the salt [Cp*2 Fe][(PhC(S)S)Zn(C6 F5 )2 ] 1, [Cp*2 Fe][((C14 H8 O2 )Zn(C6 F5 )2 )⋅] 4, and [Cp*2 Fe][((C16 H8 O2 )Zn(C6 F5 )2 )⋅] 5, respectively. The latter two species represent the first examples of isolable zinc-containing radical anions. While [(PhC(S)S)2 ] binds weakly to [Zn(C6 F5 )2 ], the diones afford the isolable adducts [(C14 H8 O2 )Zn(C6 F5 )2 ] 2 and [(C16 H8 O2 )Zn(C6 F5 )2 ] 3. Cyclic voltammetry and computational studies support the view that 4 and 5 are formed via single electron transfer (SET) to the donor-acceptor adducts, 2 and 3, respectively. Subsequent treatment of 4 and 5 with [NC5 H4 NMe2 ] affords [Zn(C6 F5 )2 (NC5 H4 NMe2 )2 ] with liberation of the dione, and regeneration of [Cp*2 Fe].