This proposal, part of the Experimental Physical Chemistry Program, uses fast laser techniques to study the dynamics of physical and chemical processes in liquids and at liquid vapor interfaces. Ultrashort pulse laser studies will be performed in the bulk and the interface of the liquid and its vapor. Orientational structure, composition, and dynamic processes at liquid interfaces will be studied. The effects of the asymmetry in forces present at an interface, but not in the bulk liquid, result in a change in dielectric and transport properties, thereby altering molecular motions, chemical equilibria, photoisomerization and other physical and chemical nonradiative processes.