Exceptionally porous metal-organic framework (MOF) compounds have been prepared by coupling large metal-biomolecule clusters with simple organic linker molecules, according to work published in Nature Communications (DOI: 10.1038/ncomms1618). The extreme porosity of MOFs compared with other porous materials along with their potential application in gas storage and separation, catalysis, and other areas has driven extensive research and some commercialization efforts. Nearly all synthetic customization of the materials to date has focused on increasing the length and tuning structural properties of the organic linkers. Jihyun An and Nathaniel L. Rosi of the University of Pittsburgh, Joseph T. Hupp and Omar K. Farha of Northwestern University, and coworkers now report success with an alternative strategy: customizing the size of the metal vertices. The team coupled large metal-biomolecule clusters, specifically zinc-adeninate groups, with simple and relatively short dicarboxylate linkers to form bio-MOF-100. The team reports that the material exhibits high surface area (4,300 m2/g) and exceptional pore volume (4.3 cm3/g), which is some 20% larger than the previous record-setting MOF.