Programming MOF Topology through Twelve-Connected Linker Isomerism.

Abstract

Linker isomerism represents a powerful, yet unexploited, strategy for programming framework topology and unlocking chemical complexity in high-connectivity reticular systems. Here, we demonstrate the reticular synthesis of two 12-connected nanographene-based zirconium metal-organic frameworks, MOF-1300 and MOF-1400, wherein network architecture is directed by the meta versus para carboxylate substitution patterns of a 12-connected linker, dodeca-carboxylate hexakis[3,5-bis(m/p-carboxyphenyl)-4,6-dimethoxyphenyl]hexabenzocoronene (m/p-HBC-LH12). The meta isomer directs the assembly of an 8-connected cubic Zr cluster to yield MOF-1300 with an unprecedented trinodal (3,6,8)-c rcb1 net, representing a new topology in reticular chemistry. Conversely, the para isomer enforces 12-connectivity at the Zr cluster with hexagonal prismatic geometry to yield MOF-1400 with a rare trinodal (3,6,12)-c kex net which has not previously been observed in Zr-MOFs. Beyond structure, both frameworks serve as solid reservoirs of photoactive nanographenes: under basic photoredox conditions, they release their molecular HBC linkers, which act as homogeneous organophotoredox catalysts for the hydrodefluorination of polyfluoroarenes under simulated solar light (AM 1.5G). This behavior highlights the potential of reticular materials as precatalysts for the delivery of molecular photocatalysts and provides a basis for exploring such materials in future photocatalytic applications.