Syntheses, Structures, Some Reactions, and Electrochemical Oxidation of Ferrocenylethynyl Complexes of Iron, Ruthenium, and Osmium

The syntheses and characterizations of several complexes containing ferrocenylethynyl
and ferrocene-1,1‘-bis(ethynyl) groups attached to M(PP)Cp‘ [M = Fe, Ru, PP = dppe, Cp‘ =
Cp*; M = Ru, Os, PP = (PPh3)2, dppe, Cp‘ = Cp] are described. Reactions with tetracyanoethene have given either tetracyanobuta-1,3-dienyl or η3-allylic derivatives, while addition
of Me+ afforded the corresponding vinylidene derivatives. Some electrochemical measurements are discussed in terms of electronic communication between the redox-active M(PP)Cp‘ groups through the ferrocene nucleus. The molecular structures of 14 of these complexes
have been determined by crystallographic methods.