NEUTRAL AND CATIONIC IRON CARBONYL-COMPLEXES SUBSTITUTED WITH THE WATER-SOLUBLE PHOSPHINES [PH(2)P(CH2)(N)PME(3)](+) (N=2, 3, 6 AND 10)

Two Series of iron carbonyl complexes of the types Fe(CO)(4)L and [CpFe(CO)(2)L](+) (L=water-soluble phosphines [Ph(2)P(CH2)(n)PMe(3)](+), n=2, 3, 6 and 10, henceforth denoted as II-, III-, VI- and X-phophos respectively), containing neutral iron(0) and monocationic iron(II) centres respectively, have been prepared and characterized by mass spectroscopy, IR and multinuclear NMR techniques. In addition to the complexes Fe(CO)(4)L, disubstituted derivatives of the type trans-Fe(CO)(3)L(2) have also been obtained as byproducts. For the complex trans-[Fe(CO)(3)(II-phophos)(2)](PF6)(2), the II-phophos P-31{H-1} resonances, formally an XAA'X' spin system, exhibit virtual coupling, to our knowledge the first such example in a bis-tertiary phosphine complex in which X and X' are P-31 nuclei.