Isostructural σ-hydrocarbyl phospholide complexes of uranium, neptunium, and plutonium.

σ-Hydrocarbyl complexes of the form [M(η5-PC4Me4)2(μ-η1:η6-CH2Ph)2K(η6-arene)] (M = La, Ce, Pr, U, Np, Pu; arene = benzene or toluene) were synthesised in one-pot reactions from [MI3(THF)4], or [U(BH4)3(toluene)] (M = U). All complexes were examined by multinuclear (1H, 13C{1H}, 31P{1H}) NMR and UV-vis-NIR spectroscopy, as well as single-crystal X-ray diffraction from which molecular metal-phosphorus bonds for Np and Pu, and a σ-hydrocarbyl metal-carbon bond for Pu, have been structurally authenticated.