Amino, bromo, nitro, and naphthalene functionalized UiO-66 metal–organic frameworks have been synthesized through reticular chemistry. UiO-66–NH2 is shown to be suitable for postsynthetic modification with a variety of anhydrides to generate new, functionalized frameworks.

UiO-66 is an archetypal zirconium-based metal−organic framework (MOF) that is constructed from hexanuclear zirconium oxide clusters as secondary building units (SBUs) and 1,4-benzenedicarboxylate (bdc) linkers. For the first time, a room-temperature solution-based synthesis is reported for UiO-66 and several of its derivatives, UiO-66-X (X = NH 2 , OH, or NO 2 ), resulting in materials that are as porous and crystalline as those made at elevated temperatures. In addition, via modulation of the temperature at which UiO-66 is synthesized, the number of defect sites can be varied. It was found through N 2 sorption isotherm analysis and potentiometric acid−base titrations that increasing the synthesis temperature from 25 to 130 °C results in a systematic decrease in the number of defect sites in UiO-66. The results suggest that, with respect to this synthetic procedure, a maximal number of defect sites is achieved [∼1.3 missing linkers per Zr 6 O 4 (OH) 4 (bdc) 6 ] at a temperature of 45 °C.

Synthesis and activation of phase-pure and defect-free metal–organic frameworks (MOFs) are essential for establishing accurate structure–property relationships.