The preparation and characterization of iron(II) complexes containing the tripodal tetraphosphine ligand tris[2-(dimethylphosphino)ethyl]phosphine, P(CH2CH2PMe2)(3) (PP3, 1), are reported. The complex FeCl2(PP3) (2) was formed by the reaction of PP3 with anhydrous iron(II) chloride. The complexes FeHCl(PP3) (3) and FeH2(PP3) (4) were formed by the reaction of 2 with Lithium aluminum hydride. Likewise, the complexes FeMeCl(PP3) (5) and FeMe2(PP3) (6) were formed by the reaction of 2 with methyllithium or dimethylmagnesium. Reaction of 2 with CO afforded a mixture of isomeric carbonyl chloride complexes [Fe(CO)Cl(PP3)](+) (7 and 8). Reaction of 2 with PPh3 afforded. [Fe(PPh3)Cl(PP3)](+) (9). The air-sensitive complexes 2-9 were characterized by multinuclear NMR spectroscopy, and 9 was characterized by X-ray crystallography. Crystals of 9 (BPh4 salt), C54H65BClFeP5, M971.09, arts monoclinic, space group P2(1)/c, a = 13.246(3) Angstrom, b = 30.314(2) Angstrom, c = 14.338(2) Angstrom, beta = 100.92(2)degrees, Z = 4; R = 0.058.