To develop novel nonlinear dyes for photonic applications, we synthesized a series of transition metal-containing phenylacetylene oligomers. The optical properties of these compounds were measured by UV/Vis, fluorescence, long-pathlength UV/Vis and nanosecond flash photolysis experiments. The sensitivity of the state energies to molecular size was a measure of their delocalization. The S 0 and T 1 states were found to be more localized than the S 1 and T n states. The results were consistent with the S 0 ->S 1 and T 1 ->T n transitions having charge transfer character, while the T 1 ->S 0 transition was from a confined state to another confined state.