The kinetics of diffusion-controlled deactivation processes is strongly affected by confinement of the reacting species in a space kept at molecular dimensions in at least one direction. In globular micelles the confinement is in all three dimensions, and the well-known kinetics is determined by a first-order rate constant representing the frequency of encounters of a pair of reactant molecules in the micelle, and the statistics of distribution of the reactants over the micelles. If the confinement is allowed to grow in one dimension into rods, or two dimensions into monolayers or bilayers, or in all three dimensions to a homogeneous solution, the deactivation kinetics is determined by one-, two-, or three-dimensional diffusion. Experimental examples of these cases are presented. Further complications occur on timescales where migration of the reactants between the dimensionally restricted structures must be considered. Of particular interest are systems which comprise clusters of small micelles, where the exchange between the micelles in a cluster is rapid. Experimental results for such a system composed of reversed AOT micelles is presented.