Synthesis of Exceptionally Stable Iron and Ruthenium eta1-tetrahedro-Tetraphosphorus Complexes. Evidence for a Strong Temperature Dependence of M-P4 £k Back Donation

At variance with white phosphorus, the most reactive allotrope of the element, which is popular for its instability and ignites spontaneously in the air, the new ƒØ1-tetrahedro-tetraphosphorus complexes [Cp*M(PR3)2(ƒØ1-P4)]Y (M = Fe, Ru; Y = Cl, PF6, BPh4, BAr¡¦4) exhibit a surprising and unprecedented thermal stability and an astonishing reluctance to react with oxygen and other oxidants