Molecular co-crystals provide a limitless means to combine diverse set of molecules into close proximity and a rigid environment. Frustrating effects of close-packing, however, have hindered chemists from gaining a level of control of order in the crystalline state that translates into an ability to systematically control properties. In this presentation, we will describe our efforts to develop a method to control both chemical reactivity and the organization of semiconductor molecules in the solid state using molecular co-crystals. The approach relies on isolating and stacking molecules within finite supramolecular assemblies held together by noncovalent forces such as hydrogen bonds and coordination bonds. For the former, we will show how controlling reactivity in the solid state can lead to the formation of molecular ladders. For the latter, we will show how enforced face-to-face stacking can be achieved in the case of thiophene and anthracene rings.