The Fayer group is pursuing research on the ultrafast dynamics, interactions, and structure of a range of complex molecular systems. A major theme of the systems under investigation is that they frequently possess mesoscopic structure, that is, structure beyond that of the short range order of a molecule and its solvent shell that commonly occurs in a liquid. The types of systems under study include water in nanoconfined systems and water interacting with interfaces, ions and other species; Room Temperature Ionic Liquids (RTILs) and their effect on solutes and how they are affected by solutes; Metal Organic Frameworks (MOFs) and their properties when they are functionalized and contain solvents in their nanopores; liquid crystals and the behavior of nanodomains in the isotropic phase and the phase transition to ordered phases; polyelectrolyte fuel cell membranes and how water behaves in the membrane’s nanochannels and the nature of proton transfer in the channels; organized surfactant systems such as reverse micelles and vesicles; supercooled liquids and their dynamics as they approach the glass transition; nanoporous silica particles that are functionalized and contain solvents in the pores; and functionalized alkyl chains on silica and gold surfaces and interactions of solvents with functionalized surfaces.