This grant in Organic and Macromolecular Chemistry provides support for challenge travel grants for approximately 40 U.S. academic participants in the XII IUPAC Symposium on Photochemistry, to be held in Bologna, Italy, 17-22 July, 1988. Challenge grants will provide a portion of the participants' travel expenses. Participants will be expected to obtain the balance of their travel and conference expenses from other sources. This funding will assure the attendance of a significant number of U.S. photochemists at the Symposium and will, thus, contribute importantly to furthering communication and collaboration across international boundaries in a major subdiscipline of chemistry.