Collect. Czech. Chem. Commun. 1997, 62, 309-317

A Specific π-Ligand Transfer Reaction via Triple-Decker Sandwich Complex Intermediates

Dieter Böhm, Frank Heinemann, Dongqi Hu, Susanne Kummer and Ulrich Zenneck

Anorganisch-Chemisches Institut der Universität Erlangen-Nurnberg, 91058 Erlangen, Germany


Photochemically generated cationic cyclopentadienyl iron fragments [FeCp]+ allow a specific stacking reaction of [(t-Bu3C3P2)Fe(t-Bu2C2P3)]. This results in the transient formation of an unstable cationic Fe-Fe triple-decker sandwich complex which decomposes by deliberating the neutral sandwich complex [CpFe(t-Bu2C2P3)], and is stacked again by a second [FeCp]+-unit, yielding the moderately stable cationic triple-decker sandwich complex [CpFe(t-Bu2C2P3)FeCp]+ with a central mi-eta5:eta5-triphospholyl ligand. Air exposure or storage of solutions at room temperature leads to a destacking and the neutral triphosphaferrocene derivative [CpFe(t-Bu2C2P3)] is formed again almost quantitatively in respect to the pentaphospha-ferrocene educt.

Keywords: Iron compounds; Triple-Decker sandwich complexes; Triphospholyl complexes.