IRON COMPLEXES CONTAINING THE TRIPODAL TETRAPHOSPHINE LIGAND P(CH2CH2PME2)(3)

The preparation and characterization of iron(II) complexes containing the tripodal tetraphosphine ligand tris[2-(dimethylphosphino)ethyl]pho sphine, P(CH2CH2PMe2)(3) (PP3, 1), are reported. The complex FeCl2(PP3 ) (2) was formed by the reaction of PP3 with anhydrous iron(II) chlori de. The complexes FeHCl(PP3) (3) and FeH2(PP3) (4) were formed by the reaction of 2 with Lithium aluminum hydride. Likewise, the complexes F eMeCl(PP3) (5) and FeMe2(PP3) (6) were formed by the reaction of 2 wit h 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). T he air-sensitive complexes 2-9 were characterized by multinuclear NMR spectroscopy, and 9 was characterized by X-ray crystallography. Crysta ls of 9 (BPh4 salt), C54H65BClFeP5, M971.09, arts monoclinic, space gr oup P2(1)/c, a = 13.246(3) Angstrom, b = 30.314(2) Angstrom, c = 14.33 8(2) Angstrom, beta = 100.92(2)degrees, Z = 4; R = 0.058.