Direct access to [(Mes*P)2As]−, a 1,3-diphosphaarsa-2-allyl anion, isoelectronic with the allyl anion (Mes* = 2,4,6-tBu3C6H2).

The reaction of As(NMe2)3 with Mes*PHLi provides a direct source of the 1,3-diphosphaarsa-2-allyl anion, [(Mes*P)2As]− (isoelectronic with the allyl anion). The equilibrium between the E,E and E,Z isomers of this anion depends on the extent of Li+ ion-pairing. [ABSTRACT FROM AUTHOR]