A Li10 Cage Containing the [C6H11P⋅⋅⋅–C(Ph)⋅⋅⋅–N]2− Ion: Umpolung in the Oligomerization of a Nitrile

Two types of anion are present in the lithium aggregate [{{[C6H11PC(Ph)N]Li2}{[H(PhCN)3(C6H11P)2]Li3}(thf)3}2]⋅2 C6H5CH3⋅2 THF obtained by the addition of C6H11PHLi to benzonitrile (PhCN), followed by deprotonation with nBuLi. In the trianion (right) the charge is located essentially in three distinct regions. The dianion (left) is the first example of this type to be structurally characterized.