Reactions of Sn(NMe₂)₂with Primary Aryl Phosphides, ArPH^-:  Synthesis and Structures of the Heteroleptic Cages [{(PhP−PPh)Sn(μ-PPh)}₂(Na·PMDETA)₄and [{Sn(μ₃-Ppy)}₃{Sn(μ₃,μ₁-pyP−Ppy)}₃]

The reaction of Sn(NMe2)(2) with the primary phosphido alkali metal complex PhPHNa (1:2 equiv, respectively) in the presence of the Lewis base donor PMDETA [(Me2NCH2CH2)(2)NMe] gives the heterometallic cage [{(PhP-PPh)Sn(mu-PPh}(2)(Na center dot PMDETA)(4) (1), containing the novel [(PhP-PPh)Sn(mu-PPh)](2)(4-) tetraanion. The analogous reaction using pyPHLi (py = 2-pyridyl) in THF/toluene as the solvent gives the neutral cage [{Sn(mu(3)-Ppy)}(3){Sn(mu(3),u(1)pyP-Ppy)}(3)] (2), having a unique "stacked" propeller arrangement in the solid state.