This project funded by the Inorganic, Bioinorganic and Organo- metallic Chemistry Program is for exploratory research on temperature-hypersensitive photostationary states and photooscillating systems. The basis of the proposed investigation is the observation that the photostationary state for certain diacidobisbipyridylruthenium(II) complexes switched from Ru(II) to Ru(III) over a remarkably small temperature interval when irradiated in chloroform solution. There was also evidence for a photooscillation between the two oxidation states under certain conditions. Elucidation of the mechanism of the photochemical behavior is a primary objective of the research although plans are outlined to examine other chemical systems that may behave in a similar fashion. %%% This research, which deals with photochemically initiated inorganic reactions, if successful could have very significant technological applications for "smart glass", i.e., changes color with temperature, various types of sensors and switches, and possibly for mass storage applications.