Herein is presented a molecular dyad comprised of a [Ru(bpy)(3)](2+) photosensitizer and an anthraquinone (AQ) acceptor coupled by an ethynyl linker ([Ru(bpy)(2)(bpy- cc-AQ)](2+)) in which activation/deactivation of photoinduced electron-transfer from the [Ru(bpy)(3)](2+) photosensitizer to the AQ acceptor is achieved and characterized as a function of the dielectric constant and hydrogen-bond donating ability of the solvent used. It is demonstrated that the rate of photoinduced electron-transfer can be modulated over several orders of magnitude (10(5)-10(11) s(-1)) by choice of solvent. Nanosecond transient absorption spectra are dominated by MLCT signals and exhibit identical decay kinetics to the corresponding emission signals. Ultrafast transient absorption and time-resolved infrared spectroscopies provide direct evidence for the formation of the charge-separated (CS) state and rapid (on the order of a few picoseconds) establishment of an excited-state pseudoequilibrium.