Ultraviolet pump, infrared probe transient absorption studies of the chelatable compound 1, Mn{eta(5)-C5H4C(O)C(SCH3)(3)}(CO)(3), dispersed in room temperature, spin-coated polyacryclonitrile (PAN) films (similar to 25 mu m thick on a CaF2 surface) are reported for the first time. Irradiation of 1 at 289 nm induces CO loss with high yield and generates the Mn-S bound chelate within 160 ps. There is no evidence for undesirable matrix cage CO recombination or secondary competing solvation pathways for this system, which may serve as the basis for future solid-state photoswitches.