Halogenodisilanes: Precursors for new disilane derivatives

Starting from hexachloro- or hexabromodisilane a wide variety of 1,2-disubs tituted tetrachlorodisilanes (RSiCl2-SiCl2R) [R = Cp*(2a), 4-iPrC(6)H(4)(Si Me3)N (2b), 2,6-iPr(2)C(6)H(3)(SiMe3)N (2c), (Me3Si)(2)CH (2d) (Me3Si)(3)C (2e), (Me3Si)(3)Si (2f)], tetrabromodisilanes (RSiBr2SiBr2R) [R = Cp* (3a), 4-iPrC(6)H(4)(SiMe3)N (3b), (Me3Si)(3)Si (3f)] and the monosubstituted pen tahalogenodisilanes Cp*SiX2SiX3 [X = Cl (4), Br (5)] were prepared. The tet rachlorodisilanes 2a-e are converted to various functionalized disilanes. A mmonolysis of 2a-e leads to the tetraaminodisilanes [RSi(NH2)(2)Si(NH2)(2)R ] 6a-e. A reduction of 2d with LiAlH2 resulted in the formation of the disi lane RSiH2SiH2R [R = (Me3Si)(2)CH] 7 and the metathesis with Me3SnF yielded the tetrafluorodisilane RSiF2- SiF2R [R = (Me3Si)(2)CH] 8. Treatment of 6d with reagents containing H acidic protons (HX) [X = Br, I and OH] leads un der elimination of NH3 to the tetrabromo- R2SiBr2SiBr2R (3d) tetraiodo- RSi I2SiL2R (C9) and the tetrahydroxodisilane RSi(OH)(2)Si(OH)(2)R (10) [R = (M e3Si)(2)CH]. Single-crystal X-ray structural analysis of 2d, 6a, 6d, and 9 are reported.