Electronic interactions in [Ru3(μ3-R2CCC6H4-4-R1)(μ-dppm)(μ-CO)(CO)7] (R1 = NO2 and R2 = Fc; R1 = NO2, CN and R2 = Ph)

The co-ordination of FcCCC(6)H(4)-4-NO2 (1) to a ruthenium carbonyl cluster to yield [Ru-3(mu(3)-FcCCC(6)H(4)-4-NO2)(mu-dppm)(mu-CO)(CO)(7)] (2) is reported. The cyclic voltammograms of these compounds and of the analogous clusters [Ru-3(mu(3)-eta(2)-C6H5CCC6H4-4-R)(mu-dppm)(mu-CO)(CO)(7)] (R= H, 3; CN, 4; NO2, 5) allowed an evaluation of the electronic communications between the different redox sites (ferrocenyl and -NO2 groups, and Ru-3 moiety) and an analysis of the relative electron donor-acceptor capabilities of each of the three redox centres that compose 2. Furthermore, the inertness of 2, compared with clusters 3-5 which loose CO readily was attributed to the interaction between the ferrocenyl group and the metallic frame.