ja0c04450_si_001.pdf (2.23 MB)
Pseudo-5-Fold-Symmetrical Ligand Drives Geometric Frustration in Porous Metal–Organic and Hydrogen-Bonded Frameworks
journal contribution
posted on 2020-07-29, 20:44 authored by Frederik Haase, Gavin A. Craig, Mickaële Bonneau, Kunihisa Sugimoto, Shuhei FurukawaReticular
framework materials thrive on designability, but unexpected
reaction outcomes are crucial in exploring new structures and functionalities.
By combining “incompatible” building blocks, we employed
geometric frustration in reticular materials leading to emergent structural
features. The combination of a pseudo-C5-symmetrical organic
building unit based on a pyrrole core with a C4-symmetrical
copper paddlewheel synthon led to three distinct frameworks by tuning
the synthetic conditions. The frameworks show structural features
typical for geometric frustration: self-limiting assembly, internally
stressed equilibrium structures, and topological defects in the equilibrium
structure, which manifested in formation of a hydrogen-bonded framework,
distorted and broken secondary building units, and dangling functional
groups, respectively. The influence of geometric frustration on the
CO2 sorption behavior and the discovery of a new secondary
building unit shows geometric frustration can serve as a strategy
to obtain highly complex porous frameworks.