Journal of the American Chemical Society, Vol.143, No.5, 2212-2216, 2021
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)(Me3SO2C4Si2(L)(2) (2). 2 exhibited a one-electron transfer when treated with 1 equiv of [Ph3C](+)[B(C6F5)(4)](-) to yield [(Me3SiC2)(2)(Me3Si)(2)C4Si2(L)(2)](center dot+)[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)(Me3SO2C4Si2(L)(2)](2+)center dot 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)(2)C4Si2(L)(2)(mu-O-2) (5) and (Me3SiC2)(2)(Me3Si)(2)C4Si2(L)(2)(mu-E) (E = S (6) and Se (7)), respectively.