The work herein describes the investigation of metal-organic frameworks for industrial applications, specifically gas phase separations of mixtures. Metal-organic frameworks are crystalline molecular scaffolds built from cationic metal vertices and organic bridging ligands. They are porous on a molecular scale and can separate gas mixtures when one component interacts more strongly with the pore walls than others. The near-infinite combination of metals and ligands allows for optimization of metal-organic framework structures for specific separations. (Abstract shortened by UMI.).