D. Osella et al., ELECTROCHEMICAL EVIDENCE OF THE REORIENTATION OF ALKYNES ON TRIMETALLIC CLUSTERS DURING A 2-ELECTRON REDUCTION, Organometallics, 12(8), 1993, pp. 3140-3144
The electrochemical two-electron reduction of isoelectronic and isostr
uctural alkyne clusters of iron and osmium has been investigated by fa
st-scan cyclic voltammetry. Both Fe3(CO)9-(EtC=CEt) and OS3(CO)7(Ph2PC
H2PPh2)(PhC=CPh) undergo a two-electron reduction. While Fe3(CO)9(EtC=
CEt) is reduced in two separate one-electron waves, OS3(CO)7(Ph2PCH2PP
h2)(PhC=CPh) displays a single two-electron wave. Fast-scan voltammetr
y detects one additional adsorption post-peak for the iron cluster whi
ch, under certain experimental conditions, gives rise to apparent anom
alous shapes of voltammograms. Differences in electrochemical pattern
of iron and osmium title compounds are interpreted on the basis of fol
low-up and concomitant isomerization reactions with respect to the fir
st electron transfer, respectively.