Reductive Degradation of Tetracobalt Cluster Complexes with a Facial C8H8 Ligand – Synthesis of [Co3(CO)3(μ3-CO)3(μ3-C8H8)]– and [Ru(C5Me5)Co3(CO)3(μ3-CO)3(μ3-C8H8)]

Redox Chemistry of [Co4(CO)3(μ3-CO)3(μ3-C7H7)(η5-C7H9)] – Reversible Carbon−Carbon Coupling versus Metal Cluster Degradation

“…Treatment of [Co 4 (CO) 3 (µ 3 -CO) 3 (µ 3 -C 7 H 7 )(η 5 -C 7 H 9 4 ] 2 ) from the pooled mother liquors.…”

“…The complex potential current response of 3 is rationalized in terms of the formation of the radical anion [3] − as the primary intermediate, which may be reversibly reduced further to give the much more stable [3] 2− and then [3] 3− . Dimerization of [3] − to give [4] 2− occurs by formation of a new carbon−carbon bond between the apical C 7 H 9 ligands. The two redox-active moieties in [4] 2− behave as independent, non-interacting redox centres.…”

“…Dimerization of [3] − to give [4] 2− occurs by formation of a new carbon−carbon bond between the apical C 7 H 9 ligands. The two redox-active moieties in [4] 2− behave as independent, non-interacting redox centres. The oxidized form 4 is unstable and dissociates back to 3 almost quantitatively, thus completing a redox cycle characteristic of a ''molecular battery''.…”

“…The oxidized form 4 is unstable and dissociates back to 3 almost quantitatively, thus completing a redox cycle characteristic of a ''molecular battery''. The homogeneous rate constant for dimerization has been evaluated as k DIM (2 [3] − Ǟ [4] 2− ) = 0.30 ± 0.05 mM −1 s −1 .…”

“…[4] On chemical reduction, cluster complexes of the type [Co 4 (CO) 3 (µ 3 -CO) 3 (µ 3 -C 8 H 8 )(L)] [1a, L ϭ η 4 -C 8 H 8 ; 1b, L ϭ η 4 -C 6 H 8 ; 1c, L ϭ η 4 -diphenylfulvene; 1d, L ϭ (CO) 2 ] [5] are degraded to give the trinuclear cluster anion [Co 3 (CO) 3 (µ 2 -CO) 3 …”