Stable Radical Cation and Dication of a 1,4-Disilabenzene.

The reaction of (LSi:)2 (1; L = PhC(NtBu)2) with 2 equiv of Me3SiC2C2SiMe3 resulted in the formation of (Me3SiC2)2(Me3Si)2C4Si2(L)2 (2). 2 exhibited a one-electron transfer when treated with 1 equiv of [Ph3C]+[B(C6F5)4]- to yield [(Me3SiC2)2(Me3Si)2C4Si2(L)2]·+[B(C6F5)4]- (3) and Ph3CCPh3, respectively. When compound 2 was treated with 2 equiv of AgOSO2CF3 a transfer of two electrons occurred to produce [(Me3SiC2)2(Me3Si)2C4Si2(L)2]2+·2[OSO2CF3]- (4) and elemental silver. The 1,4-disilabenzene 2 is disclosed of an open-shell singlet diradical character, and 3 and 4 are, respectively, the elusive stable radical cation and dication species of the 1,4-disilabenzene (2). Furthermore, 2 reacted with group 16 elements of O, S, and Se by oxidative addition to form (Me3SiC2)2(Me3Si)2C4Si2(L)2(μ-O2) (5) and (Me3SiC2)2(Me3Si)2C4Si2(L)2(μ-E) (E = S (6) and Se (7)), respectively.