Programmed Pore Architectures in Modular Quaternary Metal–Organic Frameworks

To generate metal–organic
frameworks (MOFs) that are complex
and modular yet well ordered, we present a strategy employing a family
of three topologically distinct linkers that codes for the assembly
of a highly porous quaternary MOF. By introducing substituted analogues
of the ligands, a set of eight isoreticular frameworks is delivered,
with the MOF structure systematically varied while the topology is
maintained. To combat randomness and disorder, the substitution patterns
of the ligands are designed to be compatible with their crystallographic
site symmetries. MOFs produced in this way feature “programmed
pores”multiple functional groups compartmentalized
in a predetermined array within a periodic latticeand are
capable of complex functional behavior. In these examples unconventional
CO2 sorption trends, including capacity enhancements close
to 100%, emerge from synergistic effects. Future PP-MOFs may be capable
of enzyme-like heterogeneous catalysis and ultraselective adsorption.