Structurally characterised 2,5-bis(2-hydroxyphenyl)pyrazine (H2L) can be partially or fully deprotonated to form the complexes [(acac)2Ru(µ-L)Ru(acac)2], [1], acac− = acetylacetonato = 2,4-pentanedionato, [(pap)2Ru(µ-L)Ru(pap)2](ClO4)2, [2](ClO4)2, pap = 2-phenylazopyridine, or [(pap)2Ru(HL)](ClO4), [3](ClO4). Several reversible oxidation and reduction processes were observed in each case and were analysed with respect to oxidation state alternatives through EPR and UV-VIS-NIR spectroelectrochemistry. In relation to previously reported compounds with 2,2′-bipyridine as ancillary ligands the complex redox system [1]n is distinguished by a preference for metal-based electron transfer whereas the systems [2]n and [3]n favour an invariant RuII state. Accordingly, the paramagnetic forms of [1]n, n = −, 0, +, exhibit metal-centred spin whereas the odd-electron intermediates [2]+, [2]3+ and [3] show radical-type EPR spectra. A comparison with analogous complexes involving the 3,6-bis(2-oxidophenyl)-1,2,4,5-tetrazine reveals the diminished π acceptor capability of the pyrazine-containing bridge. © 2007 The Royal Society of Chemistry.