The reactivities of aminoarsines toward diarsines

The reactions of Me₂AsNR₂ with Et₂AsAsEt₂, and of Et₂AsNR₂ with Me₂AsAsMe₂ (R = Me or Et), were investigated over the temperature range 24–75°C by using ¹H and ¹³C NMR spectroscopy. The NMR data indicate the initial formation of the unsymmetrical diarsine, Me₂AsAsEt₂, and the respective dialkylamino-dialkylarsine, Et₂AsNR₂ or Me₂AsNR₂. The Me₂AsAsEt₂ then undergoes symmetrization to yield Me₂AsAsMe₂ and Et₂AsAsEt₂. Additional competitive reactions involving AsAs-AsNandAsN-AsN systems also occur in the reaction mixture. In each case, the percentage distribution of products and reactants in the studied systems at equilibrium is independent of temperature within experimental measurement. The reaction rates are dependent upon the nature of R and the alkyl group in the diarsine. In addition, equilibrium constants for several competitive reactions have been determined.