The focus of this research will be to use directed hydrogen bonding interactions to control the size and shape of self-assembling organic structures in both solution and in the solid state. The first goal of thew work is to understand the structural features necessary for the self-organization of different cyclic and linear hydrogen bonded aggregates, some unsubstituted and some with photoactive functionality attached. The second goal is to understand the energetics of self-assembly and the balance between the favorable enthalpy and unfavorable entropy of aggregate formation. %%% With this award, the Synthetic Organic Program is supporting the research of Dr. Andrew D. Hamilton of the Department of Chemistry at the University of Pittsburgh. Professor Hamilton will focus his work on the design, synthesis and evaluation of self-assembling organic structures.