Abstract

Organometallic hydrazines of general formula Me, (2)+PF6-; MeO, (3)+ PF6-; Cl, (4)+PF6-) react with equimolar quantities of (E)-4- (2-ferrocenylvinyl)-benzaldehyde, (E)-[(?5-Cp) Fe(?5-C5H4)-CH=CH-C 6H4CHO], to afford stereoselectively, the new homodimetallic hydrazones formulated as (E)-[(?5-Cp) Fe(?6-p-RC6H4)-NHN=CH- C6H4=CH-CH-(?5-C5 H4)Fe(?5-Cp)]+PF6- (R=H, (5)+PF6-; Me, (6)+PF6-; MeO, (7)+PF 6-; Cl, (8)+PF6-). These compounds were fully characterized by elemental analysis and spectroscopic techniques (1H-and 13C-NMR, IR and UV-vis) and, in the case of complex (6)+PF6-, by single crystal X-ray diffraction methods. The rotations of the ferrocenyl unit by 37.2 out of the -NHN-CH-C6H 4=CH-CH- spacer and coordinated phenyl ring planes, may generate an unfavorable structure to allow ?-electron delocalization along the entire hydrazonato backbone between the two metals separated through bonds by more than 1.8 nm, as confirmed by the electrochemical data. © 2002 Elsevier Science B.V. All rights reserved.