Redox active organoiron alkynyl centers with a coordination site: an approach toward molecular plugs. Complexation reactions with (THF)W(CO)(5) and (PhCN)(2)MCl2 (M = Pd, Pt)

The synthesis and full characterization of the functionalized complexes 3a- c [(dppe)Cp*Fe(C = C-L)] (L = 4-Py, 3-Py, 2-Py; dppe = 1,2-bis(diphenylphos phino)-ethane; Cp* = pentamethylcyclopentadienyl) are reported. These elect roactive compounds, stable under two redox states, behave as typical pyridy l ligands towards simple metal precursors of tungsten, palladium or platinu m complexes. With (THF)W(CO)(5) bi-metallic iron-tungsten complexes [(dppe) Cp*Fe(C = C-Py)W(CO)(5)] (5a-b) were isolated. After chemical oxidation the ir corresponding [(dppe)Cp*Fe(C = C-Py)W(CO)(5)][PF6] (5a-b(+)) salts were isolated and characterized as well. With the palladium(II) and platinum(II) dichloride (PhCN)(2)MCl2 precursors, neutral, mono- and dicationic trimeta llic complexes of the type {[(dppe)Cp*Fe(C = C-4-Py)](2)MCl2}[PF6](n) (M = Pd: 8a, Pt: 10a; n = 0, 1, 2) were similarly isolated and studied. The mixe d valence states (n = 1; MV) exhibit class-I properties. (C) 1999 Elsevier Science S.A. All rights reserved.