Reticular Chemistry at Its Best: Directed Assembly of Hexagonal Building Units into the Awaited Metal-Organic Framework with the Intricate Polybenzene Topology, pbz-MOF

The ability to direct the assembly
of hexagonal building units
offers great prospective to construct the awaited and looked-for hypothetical
polybenzene (pbz) or “cubic graphite” structure,
described 70 years ago. Here, we demonstrate the successful use of
reticular chemistry as an appropriate strategy for the design and
deliberate construction of a zirconium-based metal–organic
framework (MOF) with the intricate pbz underlying net
topology. The judicious selection of the perquisite hexagonal building
units, six connected organic and inorganic building blocks, allowed
the formation of the pbz-MOF-1, the first example of
a Zr­(IV)-based MOF with pbz topology. Prominently, pbz-MOF-1 is highly porous, with associated pore size and
pore volume of 13 Å and 0.99 cm3 g–1, respectively, and offers high gravimetric and volumetric methane
storage capacities (0.23 g g–1 and 210.4 cm3 (STP) cm–3 at 80 bar). Notably, the pbz-MOF-1 pore system permits the attainment of one of the
highest CH4 adsorbed phase density enhancements at high
pressures (0.15 and 0.21 g cm–3 at 35 and 65 bar,
respectively) as compared to benchmark microporous MOFs.