Robust Zn(II)-Organic Framework for High Catalytic Activity on Cycloaddition of CO₂ with Epoxides and Reversible Iodine Uptake

Abstract

Increasingly serious natural disasters caused by excessive CO2 emission have given birth to a series of carbon-neutral technologies, among which the chemical transformation of CO2 catalyzed by metal–organic framework (MOF)-based catalysts has become a focus. Herein, the self-assembly of zinc(II) cation and designed flexible multifunctional ligand of 1,3-di(5,6-dicarboxylbenzimidazol-1-ylmethyl)benzene (H4DDBB) generated a highly robust microporous material of {[Zn(H2DDBB)]·2NMP} n (NUC-69) with 1D rectangle open channels (10.0 × 7.6 Å2). Because the inner wall of voids is densely functionalized by free −COOH groups, Nimidazole atoms, and tetra-coordinated open metal sites, activated NUC-69a exhibits high catalytic performance on the cycloaddition reactions of CO2 with epoxides under mild conditions with high turnover number and turnover frequency. In addition, NUC-69a can be used as an efficient iodine adsorbent with a maximum adsorption capacity of 0.94 g/g (4.26 I2 molecules per formulation unit) and 1.28 g/g (5.81 I2 molecules per formulation unit) in hexane solution and the volatilization phase. Hence, this work provides a productive insight into the design of multifunctional microporous MOFs by enhancing the types of active sites, which makes the developed materials a broader application prospect.

Multifunctional Dysprosium(III)–Organic Framework for Efficiently Catalyzing the Cycloaddition of CO2 and Knoevenagel Condensation under Mild Conditions

“…Based on cutting-edge research in recent years, − activated MOFs have good catalytic performance in Knoevenagel condensation due to their alkaline sites within their own confined space. For NUC-101a , there are plentiful Lewis base sites such as tetrazole groups, the pyridine group, and free carboxyl groups, which inspire us to investigate the condensation of aldehydes and malononitrile viewed as a branch of Knoevenagel condensation.…”

Nanoporous Lanthanide-Based MOFs for Catalyzing the Cycloaddition of CO2 and the Knoevenagel Condensation

“…Detailed crystal data and selected bonds and angles are listed in Tables S1 and S2. Selected PLATON calculation shows that there are two kinds of edge-shared channels including the rare hierarchical cylindrical (17 Å) and quasi-quadrilateral (8 Å) channels, both of which lead to the total potential solvent-accessible void volume of 4480–4450 Å 3 with a high porosity of 64–65%, higher than most documented three-dimensional (3D) lanthanide-cluster-based MOFs self-assembled from Ln III ions and organic acids, for instance, Er 2 (TBDC) 3 (phen) 2 (38.9%), {Pr 3 (ATPT) 2 (HATPT) 4 } n (47.9%), {Ln­(TPO)} n (48.4–49.0%), {Ln­(BTB)} n (49.6%), {Ln 3 (PTTBA) 2 } n (51.2%), {Nd 3 (ATPT) 3 (HATPT) 3 } n (51.0%), and NUC-38 (56.3–56.7%) . It is worth emphasizing that NUC-110 series can serve as a Lewis acidic catalyst due to the fact that each Gd­(III) ion in octagonal-nanoporous channels will fall into the defective hexacoordination configuration after activated dehydration.…”

Highly efficient iodine uptake and iodate selective probe in a 3D honeycomb-like copper–organic framework based on in situ ligand transformation

“…17,18 There are many interesting examples of such MOF or CP materials that have been successfully used in the fields of gas adsorption and storage, 19 molecular recognition, 20–23 and chemosensors. 24–26 Although many efforts have been devoted to the application of porous luminescent frameworks in the elimination of toxic waste, 27–32 the exploration of these frameworks in the management of radioactive waste, 1 especially in the treatment of radioiodine species, 33–35 remains necessary and still represents an important challenge. A popular promising strategy for excellent controllable capture of iodine on porous frameworks is based upon host−guest interactions built between the porous MOF functionalities and iodine especially inside the hole.…”