| Popis: |
Ligand exchange reactions between ferrocene (FcH) and dibenzodioxin (IIIA), phenoxathiin (IIIB), thianthrene (IIIC) or phenoxazine (IIID) were carried out to give η 6 -heterocycle-η 5 -cyclopentadienyliron cations for comparison with previous preparations of such cations from nucleophilic substitution reactions of the η 6 - o -dichlorobenzene-η 5 -cyclopentadienyliron cation with two nucelophilic groups located in the 1,2-positions of a benzene ring [1]. Using a large excess of FcH, ligand exchanges with these heterocyclic systems also gave rise to the η 6 ,η 6 -heterocycle-di-η 5 -cyclopentadienyliron dications. The trans -orientation for the two CpFe + groups was found for the dications from IIIA and IIID, while both cis - and trans -dications were formed from IIIB and IIIC. A possible explanation for this difference, based on the planar or folded shape for the heterocyclic molecule, was proposed. |
