The mono- and binuclear ruthenium complexes [(tpy)Ru-II(tphz)](Pr-6)(2). 3H(2)O (2) and [(tpy)Ru-II(tphz)Ru-II(tpy)]-(PF6)(4). 3H(2)O (3), where tphz (1) is the fully conjugated tetrapyrido[2.3-a:3',2'-c:2 ",3 "-h:3''',2'''-j]phenazine, have been prepared and characterized. The analysis of the intervalence band of the mixed-valence [(tpy)Ru-II(tphz)-Ru-III(tpy)](5+) showed that it belongs to the class II with an electron coupling parameter V-ab Of 0.05 eV, much smaller than for the analogous class LII 2,3,5,6-tetrakis(2-pyridyl)pyrazine (tpp) complex (V-ab = 0.4 eV). This discrepancy has been interpreted as a lack of adaptation of tphz to the chelation of the ruthenium atoms.