85356-58-7Relevant academic research and scientific papers
Electron transfer in organometallic clusters. 2. Ferrocene-tricobalt carbon cluster compounds with multiple redox sites
Colbran, Stephen B.,Robinson, Brian H.,Simpson, Jim
, p. 943 - 951 (1983)
The redox chemistry of the cluster compounds (R)FcCCo3(CO)9-nLn [R = H, n = 0 and 1 for L = PPh3, P(C6H11)3, and P(OR)3 and n = 2 for L = P(OR)3; R = Ac, n = 0] and (R)Fc(CO)CCo3(CO)9 (R = H, Me) has been studied by electrochemical and spectroscopic techniques. Regioisomers of the derivatives AcFcCCo3(CO)9 and MeFc(CO)CCo3(CO)9 were characterized. The prototypal FcCCo3(CO)9 forms a reversible redox series [1+,0] ? [0,0] ? [0,1-]. The reduction center is the cluster, and a radical anion was detected by ESR methods. Salts of the [1+,0] species were isolated and the IR, M?ssbauer, and electronic spectra confirm the positive site as the Fc moiety. Replacement of one CO by a Lewis base does not change the accessible oxidation states but the formation of [0,1-] becomes irreversible; cationic salts were characterized. The [1+,1+] oxidation state becomes accessible on the coordination of an additional Lewis base. A detailed analysis of the electrochemical and spectroscopic data suggests that there is a weak interaction between the redox sites, the cluster acting as an electron-withdrawing substituent to the Cp ring which in turn acts as a π donor to the cluster. A useful model is to regard one ring acting as a fulvene moiety interacting with a Co3(CO)9 cluster.
