This award will support a two-year U.S.-Japan Cooperative Photoconversion/Photosynthesis Research Program project between Professor Ronald Christensen, Department of Chemistry, Bowdoin College, Brunswick, Maine, and Professor Keitaro Yoshihara, Department of Electronic Structure, Institute for Molecular Science, Okazaki, Japan. The collaboration will focus on the spectroscopy and dynamics of the S1 and S2 excited states of simple tetraenes and trienes in supersonic molecular beams. The goal is to obtain a more detailed understanding of photoisomerization in phototypical polyene systems. This project to study the electronic spectra of polyenes involves cooperative experiments between scientists with complementary skills and facilities. Their studies using fluorescence and fluorescence excitation techniques promise to make substantial contributions to ongoing research and will complement other methods based on multiphoton ionization. Professor Christensen will travel to Okazaki to purify his compounds there and will participate in the conduct and interpretation of the spectroscopic experiments.