Synthesis of New Bidentate Phosphine Ligands Containing Saturated Phosphorus Heterocycles.

The synthesis of two ethylene-bridged bidentate phosphines is described. 1,2-Bis(1-phospholano)ethane ((C4H8)PCH2CH2P(C4H8)) was synthesized by the stepwise addition of 2,2-dioxo-1,3,2-dioxathiepane to H2PCH2CH2PH2. 1,2-Bis(1-phosphorinano)ethane ((C5H10)PCH2CH2P(C5H10)) was synthesized by the novel photochemical addition of 1,4-pentadiene to H2PCH2CH2PH2. These bis(phosphines) form two-to-one complexes of the form Fe(PP)2Cl2 when added to iron(II) chloride.