Abstract

The homobimetallic hydrazone complex [CpFe(?6-p-CH 3C6H4)NHN=C(C6H4 -p-CH3)(?5-C5H4) FeCp]+PF6 - (2) (Cp = ?5 -C5H5) is stereoselectively formed by reaction of the organometallic hydrazine precursor [CpFe(?6-p-CH 3C6H4-NHNH2)]+ PF6 - with the sterically demanding p-toluoylferrocene CpFe(?5-C5H4 )CO(C6H4-p-CH3) (1) in refluxing ethanol. Compound 2 has been fully characterized by IR, UV-vis, and 1H NMR spectroscopy, cyclic voltammetry and by an X-ray diffraction analysis. The most striking features of the crystal structure are the syn-conformation of the two organometallic units, the long Fe-Cipso bond distances and the slight cyclohexadienyl character at the coordinated C6 ring with a folding angle of 6.1°, and that coordinated C6- and C5-rings of the binucleating ligand are almost coplanar with a dihedral angle of 8.1°. The crystal structure of the p-toluoylferrocene 1 is also presented. © 2005 Académie des sciences. Published by Elsevier SAS. All rights reserved.