Synthesis, structure and redox chemistry of ferrocenylsilylmethylidinetricobaltnonacarbonyl complexes, FcSi(R)2CCo3(CO)9, 1,1'-Fc'2 (R=Me, Et, Ph) and their derivatives

Article abstract of DOI:10.1016/0022-328X(92)85078-B

Reaction between the ferrocenyl silanes FcSiR2H and 1,1'-Fc'2 (R=Me, Et, Ph) and HCCo3(CO)9 gives the corresponding ferrocenylsilylmethylidinetricobaltnonacarbonyl complexes FcSi(R)2CCo3(CO)9 and 1,1'-Fc'2 in good yield.Spectroscopic data include 29Si NMR.The crystal structure of 1,1'-Fc'2 has been determined by an X-ray diffraction study.Thermal and electron-transfer catalysed substitution reactions with Lewis bases were successful except for the cluster 1,1'-Fc'2, where an unusual cleavage of the Fc-Sibond takes place.Electrochemical and ESR studies of the complexes FcSi(R)2CCo3(CO)9 and 1,1'-Fc'2 (R=Me, Ph) showed a one-electron oxidation centred on the ferrocenyl moiety and a one- or two-electron reduction dependent on the number of CCo3 redox centres.The observed electrochemistry is consistent with electrochemically non-interacting redox centres.Chemical oxidation of FcSi(Me)2CCo3(CO)9, 1,1'-Fc'2 and FcSi(Me)2CCo3(CO)8L (L=P(OMe)3, PPh3, PCy3) gave the respective monocations, whereas oxidation of FcSi(Me)2CCo3(CO)72 produced a dication.