Beiträge zur Chemie des Phosphors, 91 [1]. Li3P7, ein Polyphosphid mit fluktuierenden Bindungen: Synthese aus P2H, und Überführung in P7H3 / Contributions to the Chemistry of Phosphorus, 91 [1] Li3P7, a Polyphosphide with Fluctuating Bonds: Synthesis from P2H4 and Conversion to P7H3

Abstract

Trilithiumheptaphosphide, Li3P7 · 3 solvents (monoglyme, THF) (1), was obtained as the final product in the reaction of diphosphane-4 with n-C4H9Li or LiPH2. 1 was charac­terized by elemental analysis, IR, Raman and NMR spectroscopy as well as by the formation of the derivatives (Me3Si)3P7 and P7MO3 (3). Studying the temperature depend­ence of the 31P NMR spectrum, all P atoms in the cage structure of 1 were found to become equivalent at + 80 °C. Thus trilithiumheptaphosphide is the first known poly­phosphide with fluctuating bonds. Silylation of 1 with Me3SiCl and subsequent solvolysis with MeOH leads to the corresponding hydride, P7H3 (2), which can be remetalated to the lithium salt 1. 2 was also characterized by its IR, Raman and mass spectra.