Hydrogen Polyphosphides P3H2(3-) and P3H3(2-): synthesis and crystal structure of K3(P3H2).2.3NH3, Rb3(P3H2).NH3, [Rb(18-crown-6)]2(P3H3).7.5NH3, and [Cs(18-crown-6)]2(P3H3).7NH3.

The incongruous solvation of polyphosphides and phosphanes or the direct reduction of white phosphorus in liquid ammonia leads to the hydrogen polyphosphides catena-dihydrogen triphosphide, P(3)H(2)(3-), and catena-trihydrogen triphosphide, P(3)H(3)(2-), in the crystalline compounds K(3)(P(3)H(2)).2.3NH(3) (1), Rb(3)(P(3)H(2)).NH(3) (2), [Rb(18-crown-6)](2)(P(3)H(3)).7.5NH(3) (3), and [Cs(18-crown-6)](2)(P(3)H(3)).7NH(3) (4).

Dimers of heptapnictide anions: As14 4- and P14 4- in the crystal structures of [Rb(18-crown-6)]4As14.6NH3 and [Li(NH3)4]4P14.NH3.

Compounds [Rb(18-crown-6)]4As14.6NH3 (1) and [Li(NH3)4]4P14.NH3 (2) were prepared by the reaction of Rb4As6 with SbPh3 and 18-crown-6 and by the reduction of white phosphorus with elemental lithium in liquid ammonia, respectively. Both were characterized by low-temperature single-crystal X-ray structure analysis. They were found to contain the Ci symmetrical Pn14(4-) anion (Pn = P, As), which consists of two nortricyclane-like Pn7-cages connected by a single bond. Molecular complexes of [Rb(18-crown-6)(NH3)]2[Rb(18-crown-6)]2As14 are formed in 1, which are connected to fanfold sheets via N-H...O bonds. The anion is isolated in 2, and N-H...N bonds result in the formation of {[Li(NH3)4](mu-NH3)2[Li(NH3)4]}2+ cationic complexes.