Substituient Modified Covalent Organic Frameworks for Applications in Size Selective Separations*

Despite efforts, controlled placement of atoms, dopants, vacancies, and intercalates into crystalline lattices is only achieved in few systems and limited circumstances. Recent developments using metal or covalent organic frameworks (MOFs/COFs) show promise as synthetically configurable motifs. COFs are frameworks whose crystals are punctuated by a lattice of ordered nanopores where size, spacing, and filling are controlled. These nanopores are populated with substituents creating tailored properties for charge/size selective separations, particular emission properties, and Fermi level control. Here, we present the synthesis, characterization, and functional properties of four different COFs. Characterization includes atomic force microscopy, X-ray diffraction, and electron microscopy to show that the COFs are 2D, crystalline, and uniform, respectively. Finally, we show that COFs can be used to separate ions and proteins by size/charge, demonstrating the technological utility of these materials.