The halogen redistribution reaction in the binary [nBu2SnCl] 2O/[nBu2SnBr] 2O system is examined by 119Sn-and 13C-NMR spectroscopy. Binary mixtures of [nBu2SnCl] 2O and [nBu2SnBr] 2O reach equilibrium rapidly at room temperature. The reactant dimers are found to be in equilibrium with all five possible mixed distannoxane dimers in the equimolar mixture. These mixed distannoxane dimers differ in the ratio of Cl and Br as well as the ...