Preparation of Cationic [(R 2 N)P 5 Cl] + ‐Cage Compounds from [(R 2 N)PCl] + and P 4

The reaction of several amino‐substituted mono‐ and dichlorophosphanes (R 2 N) n PCl 3– n ( n = 2, R = i ‐Pr; n = 1, R = i ‐Pr, Cy) with GaCl 3 to form phosphenium cations [( i ‐Pr 2 N) 2 P] + ( 13 + ) and [(R 2 N)PCl] + ( 14a, b + ) has been investigated. The isolation and fully characterization of the first amino‐ and chloro‐substituted phosphenium cation 14b [GaCl 4 ] was accomplished. The insertion of these phosphenium ions into P–P bonds of dissolved P 4 was examined. Amino‐ and chloro‐substituted phosphenium cations 14a, b + readily form the corresponding P 5 + ‐cages 15a, b + . No reaction was observed for the less electrophilic diamino‐substituted phosphenium cation 13 + . The molecular structures of [ 14b ][GaCl 4 ] and [ 15b ][Ga 2 Cl 7 ] are presented and, furthermore, the intriguing NMR spectra of the P 5 + ‐cations 15a, b + are discussed.