Design and Synthesis Aspects of Soluble Organic Semiconductors John Anthony, University of Kentucky Short abstract: By careful functionalization, planar organic semiconductors can be influenced to adopt a variety of intermolecular orientations in the solid state. Pi-stacking in 1-, 2-, and 3-dimensions, as well as a variety of herringbone orientations can be obtained by careful selection of the functional group, and the influence of packing on stability, film forming ability and device performance will be discussed. A common driving force for semiconductor functionalization is to improve solubility. Where the added groups lead to extremely high solubility, the ability to purify the resulting material by sublimation is typically severely diminished. In this case, careful purification of the starting materials and optimization of reaction conditions is critical to the preparation of materials pure enough for device uses or for the formation of high-purity single crystals, and some of our progress in the optimization our synthetic approaches to organic semiconductors will be presented.