“Naked” Phosphanediide Chains and their Fragmentation into Diphosphene Radical Anions

Encapsulation of the Na+ ions of the [Na2(P4R4)] ion triple with a R,R or S,S configuration at the inner phosphorus atoms by cryptands has enabled cation-separated dianions to be obtained in a crystalline form. Fragmentation of the {Na([2.2.2]cryptand)}2(P4R4) into radical anions (P2R2).− occurs in solution (see scheme), as determined by EPR spectroscopy.