Beiträge zur Chemie des Phosphors, 96 [1] Darstellung und 31P-Kernresonanzspektrum von isotopen-substituiertem Trilithium-heptaphosphid, 6Li3P7 / Contributions to the Chemistry of Phosphorus, 96 [1] Preparation and 31P NMR Spectrum of Isotopicly Substituted Trilithiumheptaphosphide, 6Li3P7

Abstract

Abstract The P7-skeleton of trilithiumheptaphosphide, Li3P7 (1), was proved to possess the earlier reported tricyclic structure [2] by complete analysis of the 31P NMR spectrum of 6Li3P7 observed at - 60 °C. The 6Li isotopic substitution was carried out to avoid the line broadening caused by the large quadrupole moment of the 7Li isotope. The unambiguous elucidation of the Li3P7 structure confirmed that the exchange process which causes all P atoms to become equivalent above room temperature is analogous to that in bullvalene. A comparison of the chemical shifts with those of (Me3Si)3P7 leads to the result that the P7-skeleton in Li3P7 is noticeably compressed along its threefold axis, thus indicating a predominant ionic character.