Expanding the Structural Topologies of Rare-Earth Porphyrinic Metal–Organic Frameworks through Ligand Modulation

Expanding the structural diversity of porphyrinic metal–organic
frameworks (PMOFs) is essential to develop functional materials with
novel properties or enhanced performance in different applications.
Herein, we establish a strategy to construct rare-earth (RE) PMOFs
with unprecedented topology via rational functionalization of porphyrinic
ligands. By introducing phenyl/pyridyl groups to the meso-positions of the porphyrin core, the symmetries and connectivities
of the ligands are tuned, and three RE-PMOFs (BUT-224/-225/-226) with
new topologies are successfully obtained. In addition, BUT-225(Co),
with both the Lewis basic and acidic sites, exhibits enhanced CO2 uptake and higher catalytic activity for the cycloaddition
of CO2 and epoxides under mild conditions. This work reveals
that the RE-PMOFs with novel topologies can be rationally designed
and constructed through ligand functionalization, which provides insights
into the construction of tailored PMOFs for various applications.