Reaktionen von NaAlH4 mit primären Silylphosphanen und ‐arsanen: Synthese und Kristallstruktur eines cyclischen Natriumphosphanylalanats und eines polycyclischen Natriumarsanylalanats

Reaction of NaAlH4 with Primer Silylphosphines and Silylarsines: Synthesis and Crystal Structure of a Cyclic Sodium Phosphanylalanate and a Polycyclic Sodium Arsanylalanate The reaction of sodium aluminium hydride with H₂PSiMe₃ in the molar ratio 1:4 yields the compound [H₂Al{P(SiMe₃)₂}₂Na(dme)₂] ( 1 ). Central structural motif of this compound in a four‐membered AlP₂Na ring. Surprisingly the phosphorus atoms in the ring wear two exocyclic silylgroups each. From the reaction of NaAlH₄ with the primer silylarsine H₂AsSiiPr₃ in THF the ionic compound 2 can be obtained. In this compound cyclic [(H₂Al)₃(AsSiiPr₃)₃]^3‐ anions coordinate the sodium counter‐ions by the hydride ligands as well as by the arsenic atoms.