A series of covalently linked Ru(bipyridine)(3)-donor-acceptor complexes was prepared where the donor-to-chromophore and acceptor-to-chromophore methylene chain lengths were varied. Time-resolved absorption studies were performed to elucidate intramolecular electron transfer rates. The electron donor in the above series is a phenothiazine moiety Linked to a bipyridine by a (-CH2-)(p), p = 3-8 chain, and the electron acceptor is an N,N’-diquaternary-2,2’-bipyridinium moiety Linked to a bipyridine by a (-CH2-)(m), m = 2, 3, 4 chain. Oxidative quenching of the Ru(bipyridine)(3) metal-to-ligand charge transfer (MLCT) state followed by phenothiazine-to-ruthenium electron transfer resulted in a long-lived charge-separated state. A wavelength-dependent excitation resulted in a slowly decaying absorption which is assigned to the excited-state phenothiazine. The magnitude of this component in the transient absorption serves as an internal standard for determining relative quantum yield for formation of the charge-separated state. Marcus inverted region behavior was observed in back electron transfer. Rate constants for electron transfer from phenothiazine to Ru(III) decreased as the length of the bridging chain increased from p = 4 to 8. Chain length independence of the back electron transfer rate in the series of complexes with varied chromophore-acceptor distances (m = 2, 3, and 4) suggests the formation of an association complex during oxidative quenching of MLCT state and argues against a sigma-bond superexchange pathway for back electron transfer.