η-Benzenebis(trimethylphosphine)iron as a precursor to [Fe(η-C5R5)(PMe3)2](R = H or Me) derivatives: the equilibrium [Fe](PMe3)Et ⇌[Fe](η-C2H4)H + PMe3, where [Fe]= Fe(η-C5Me5)(PMe3)
Abstract
New or improved syntheses of the compounds [Fe(η-C6H6)(PMe3)2], [Fe(η-C5R5)(PMe3)2X](R = H or Me; X = H, Me, Et, or Cl), [[graphic omitted]CH2)(PMe3)2], [Fe(η-C5H4CH2CH2I)(PMe3)2I], [Hg{Fe(η-C5R5)(PMe3)2}2](R = H or Me), and [Fe(η-C5R5)(PMe3)3]BF4(R = H or Me) are described. The thermal equilibrium [Fe(η-C5Me5)(PMe3)(η-C2H4)H]+ PMe3⇌[Fe(η-C5Me5)(PMe3)2Et] has been demonstrated and studied by variable-temperature n.m.r. spectroscopy.