Oxidation of tetraaryldistibanes: syntheses and crystal structures of diarylantimony oxides and peroxides, (R2Sb)2O, (R2Sb)4O6 and (R2SbO)4(O2)2 (R=Ph, o-Tol, p-Tol)

Tetraaryldistibanes, (R2Sb)2 (R=Ph, o-Tol, p-Tol) are synthesized by the reactions of R2SbNa with BrCH2CH2Br in liquid ammonia. They react with air oxygen to form (R2Sb)2O and (R2Sb)4O6. The reactions of (R2Sb)4O6 with H2O2 give peroxides, (R2SbO)4(O2)2. Single-crystal X-ray structure analyses reveal that the conformations of the (R2Sb)2O molecules are close to syn–syn (R=Ph) or to syn–anti (R=o-Tol, p-Tol). (Ph2SbO)4(O2)2 is an antimony-oxygen cluster with μ4-peroxo ligands.