Novel Alkali Metal Phosphanide Aggregates

摘要

Lithium phosphanides of the type LiPR_2 (R=H, alkyl, aryl, triorganosilyl) are key reagents in organophosphorus synthesis. They are capable of aggregation (Cluster formation) and like the homologous amides often have two-dimensional, ladderlike structures A. Nevertheless polymeric chains B and helical strands C have also been observed. These structural differences and the degree of oligomerization x (x>2) are based primarily on the spatial requirements of the substituents and the tatio of the numberof lithium to donor solvent centers. This is , for example, confirmed very well by systematic investigations of the LiP (SiMe_3)_2/donor solvent system.