Chloride-Bridged Triruthenium Complexes

In CH2C12 solution, these complexes exhibit a one-electron oxidation and two separate one-electron reductions, all the processes being chemically reversible, Table 3.28b 

The electrode potentials well reflect the electron-donating power of the phophine substituents. 

As a consequence of such a redox picture, the corresponding monocations and monoanions have been isolated in particular, the RuIn—Rum-Ruin monocation [Ru3Cl8(PEt3)4]+ has been crystallogra-phically characterized, Table 4.28b 

The last series of Ru3C1 family is concerned with the monocations [Ru3C16(PR3)6] + (R = Et, Bu), in which all the terminal chloride ligands of the [Ru3C112]4 precursor have been replaced by phosphines.29 These complexes can be formally represented as Runi-Run-Run arrays, but, as deducible from their typical structural parameters reported in Table 4, with respect to the Runi-Run-Runi [Ru3C18(PR3)4] complexes, the one more electron looks like delocalized on both the two outer Ru atoms. 

Complementary to the redox behaviour of the series [Ru3C18(PR3)4], the extra electron present in [Ru3C16(PR3)6] + causes the occurrence of two reversible one-electron oxidations and a reversible one-electron reduction, Table 5.29 

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