In situ infrared spectroelectrochemical studies of [Ru6C(CO)17] and [Ru6C(CO)16]2-:: the redox induced conversion of carbon monoxide to carbon dioxide

Cyclic voltammetry and in situ infrared spectroelectrochemistry and have been used to investigate the redox behaviour of [Ru6C(CO)(17)] and [NBu4](2)[Ru6C(CO)(16)]. Under strictly anaerobic conditions, the electrochemical reduction of [Ru6C(CO)(17)] yields only [Ru6C(CO)(16)](2-). However. in the presence of O-2, the reduction of [Ru6C(CO)(17)] produces 1.1-1.3 mole of CO2 per mole of cluster, in addition to [Ru6C(CO)(16)](2-) and some cluster degradation products. Re-oxidation or electrogenerated [Ru6C(CO)(16)](2-) results in the reformation of [Ru6C(CO)(17)]. The conditions under which oxidation of chemically prepared [Ru6C(CO)(16)](2-) leads to the formation of [Ru6C(CO)(17)] have also been established. The oxidation of [NBu4](2)[Ru6C(CO)(16)](2-) in the absence of a GO-source gives only ill-defined products, as does oxidation in the presence of CO2, such that [Ru6C(CO)(16)](2-) does not scavenge CO from other cluster molecules to form [Ru6C(CO)(17)]. The oxidation of a GO-saturated solution of [NBu4](2)[Ru6C(CO)(16)] produces near quantitative yields of [Ru6C(CO)(17)]. Mechanisms have been proposed to account for these interconversions.