C2-bridged titanocene-ferrocenyl complexes:: Synthesis, reaction chemistry, and electrochemical behavior

LiC=CFc (2; Fc = (eta(5)-C5H4)(eta(5)-C5H5)Fe) reacts with [Ti]Cl-2 (1a) ([Ti] = (eta(5)-C5H4SiMe3)(2)-Ti) in a 2:1 molar ratio to produce the C-2-bridged titanocene-ferrocenyl complex [Ti](C=CFc)(2) (3). While treatment of heterotrinuclear 3 with Ni(CO)(4) (4) affords the heterotetranuclear tweezer complex {[Ti](C=CFc)(2)}Ni(CO) (5), reaction of 3 with NiCl2 (6) yields Fc-C=CC=C-Fc (7) along with [Ti]Cl-2 (1a) and Ni-0 in a redox reaction. 7 can also be synthesized in the chemical oxidation of 3 with 2 equiv of AgPF6. The electrochemical behavior of compounds 3 and 5 is discussed. The X-ray structure analysis of complex 3 is reported.