Treatment of anhydrous FeX2 (X = Cl, Br, I) with one equivalent of bis(diphenylphosphino)ethane (dppe) in refluxing THF afforded analytically pure white (X = Cl), light green (X = Br), and yellow (X = I) [FeX2(dppe)]n (X = Cl, ; Br, ; I, ). Complexes are excellent synthons from which to prepare a range of cyclopentadienyl derivatives. Specifically, treatment of with alkali metal salts of C5H5 (...