Influence of Spatial Restrictions on Equilibrium Reactions: A Case Study about theExcimer Formation of Pyrene

(Chemical) processes under spatial confinements are important for a number of areas, as for instance in catalysis (chemistry) or enzymatic reactions (biology). The role of the spatial restriction parallel to the functional interactions in these systems is hard to trace. Ordered mesoporous silica materials are ideal to provide a multiplicity of parallel, just nanometer-large, well-defined confinements. Therefore, they are ideal to act as model compounds for the examination of spatial confinement effects. In the current contribution, a bimolecular reaction, the formation of excimers of pyrene, is studied under varying confinement conditions in ordered mesoporous silica materials. It will be shown that spatial confinement changes both the excimer formation equilibrium and the kinetics of excimer relaxation.