Robust Corrole-Based Metal–Organic Frameworks with Rare 9-Connected Zr/Hf-Oxo Clusters

Abstract

The corrole unit from the porphyrinoid family represents one of the most important ligands in the field of coordination chemistry, which creates a unique environment allowing for the observation of unusual electronic states of bound metal cations and has shown great promise in various applications. Nevertheless, studies that directly and systematically introduce these motifs in porous crystalline materials for targeting further functionalizations are still lacking. Herein, we report for the first time the construction of two robust corrole-based metal–organic frameworks (MOFs), M6(μ3-O)4­(μ3-OH)4­(OH)3­(H2O)3­(H3TCPC)3 (M = Zr for Corrole-MOF-1 and M = Hf for Corrole-MOF-2, H3TCPC = 5,10,15-tris­(p-carboxylphenyl)­corrole), which are assembled by a custom-designed C 2ν -symmetric corrolic tricarboxylate ligand and the unprecedented D 3d -symmetric 9-connected Zr6/Hf6 clusters. The resultant frameworks feature a rare (3,9)-connected gfy net and exhibit high chemical stability in aqueous solutions within a wide range of pH values. Furthermore, we successfully prepared the cationic Corrole-MOF-1­(Fe) from the iron corrole ligand, which can serve as an efficient heterogeneous catalyst for [4 + 2] hetero-Diels–Alder reactions between unactivated aldehydes and a simple diene, outperforming both the homogeneous counterpart and the porphyrinic MOF counterpart.

A Corrole‐Based Covalent Organic Framework Featuring Desymmetrized Topology

“…Due to the versatility of corrole derivatives, it is a bright prospect to explore their functional materials via heterogenization into porous organic polymers (POPs), covalent organic frameworks (COFs), and metal–organic frameworks (MOFs) . However, studies that directly introduce these attractive motifs into porous crystalline framework materials for achieving further functionalizations have been barely reported . Indeed, fine‐tuning and controllable construction of networks incorporating corrole moieties remains a great synthetic challenge.…”

Corroles and Hexaphyrins: Synthesis and Application in Cancer Photodynamic Therapy

“…Metal–organic frameworks (MOFs) are porous crystalline materials composed of a three-dimensional (3D) network of metal, held in place by multidentate organic molecules. Zhang and coworkers developed robust corrole-based MOFs (e.g., 84 ) using 9-connected Zr 6 or Hf 6 and corrole as the organic linker ( Scheme 31 ) [ 72 ]. The free base corrole 81 was prepared in 21% by the reaction of pyrrole with methyl p -formylbenzoate ( 80 ) in the presence of HCl, followed by oxidation with p -chloranil.…”

Metal–Organic Frameworks Based on Group 3 and 4 Metals

“…[39] The number of Ln nuclei in Ln 3+ clusters was often controlled by the preferred coordination geometry of ligands [32] and the reaction environments. [37] [195] Corrole-MOF-1 Zr 6 O 4 (OH) 7 (H 2 O) 3 (CO 2 ) 9 TCPC 3,9-c gfy 2545 [193] MOF-525 Zr 6 O 4 (OH) 4 (CO 2 ) 12 TCPP 4,12-c ftw 1936 [197,198] The largest An(IV)-oxo cluster reported is An 38 complexes including U 38 , [40,41] Pu 38 and Np 38 . [42] By controlling releasing kinetics of water in an esterification process, U 38 clusters can be obtained as a result of hydrolysis.…”

“…[233,241] The robust corrole-based Zr-MOF, corrole-MOF-1(Fe), can serve as an excellent heterogeneous catalyst for [4 + 2] hetero-Diels-Alder addition reaction between unactivated aldehydes and a simple diene. [193] The catalytic performance of corrole-MOF-1(Fe) is better than those of the homogeneous counterpart and the Zr-MOF counterpart based on porphyrinic linkers.…”

“…Ma and co‐workers also reported a tritopic corrole linker based Zr‐MOF, corrole‐MOF‐1, in which Zr cluster is also 9‐connected. [ 193 ] The Zr clusters in corrole‐MOF‐1 are linked through 3‐connected TCPC 3− linkers (H 3 TCPC = 5,10,15‐tris(p‐carboxylphenyl)corrole) to form a mesoporous 3D framework containing a large hexagonal channel along c axis. Overall, corrole‐MOF‐1 adopts a (3,9)‐c gfy topology network.…”