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.