Heterometallic Metal-Organic Framework Based on [Cu4I4] and [Hf6O8] Clusters for Adsorption of Iodine

Abstract

Heterometallic metal-organic framework (MOF) as a kind of porous material is very important because of its excellent properties in catalysis, magnetic, sensor, and adsorption fields, but the reasonable design and syntheses of these are still challenging. Herein, we prepared one heterometallic MOF with the formula [Hf6(μ3-OH)8(OH)8][(Cu4I4) (ina)4]2·22DMF (NS-1, ina = isonicotinate). Single-crystal X-ray diffraction analysis revealed that NS-1 is a three-dimensional network with flu topology, constructed from 8-connected [Hf6(μ3-OH)8(OH)8]8+ and 4-connected [Cu4I4] clusters as second building units (SBUs). To our best knowledge, NS-1 is a rare example with two different metal clusters as SBUs in heterometallic Hf-based MOFs. Interestingly, NS-1 exhibits a reversible adsorption performance for iodine in the cyclohexane solution, the adsorption kinetics fits well with the pseudo-second-order equation, and the Freundlich model relating to multilayer adsorption better describes the process of iodine absorption.

Adsorption-based capture of iodine and organic iodides: status and challenges

“…Halide sites are electron-rich and can act as Lewis bases to facilitate I 2 adsorption. 79,80 Brunet et al examined the I 2 adsorption on a porous MOF ([(ZnI 2 ) 3 (TPT) 2 ·5.5(C 6 H 5 NO 2 )] n ), in which iodides were attached to Zn to form metal iodide sites. 81 Single-crystal X-ray crystallography showed that the guest I 2 molecules were initially bound with two terminal iodides in the framework to form [I 4 ] 2− units.…”

Construction of a triazine polycarboxylate Co-MOF with flexible and rigid coordination arms as well as excellent catalytic reduction and adsorption properties

“…11). Compound 1 has a greater capacity for adsorption than some materials mentioned in the literature 65–73 (Table 3). Q e = ( C 0 − C e ) V / m here, C 0 stands for the beginning concentration, C e represents the concentration at equilibrium, V represents the volume of iodine, and m is the mass of compound 1 .…”

“…11). Compound 1 has a greater capacity for adsorption than some materials mentioned in the literature [65][66][67][68][69][70][71][72][73] (Table 3).…”

Cluster‐Based Crystalline Materials for Iodine Capture

“…Recently, Chen et al. reported that NS‐1 with flu topology is constructed from 8‐connected [Hf 6 (μ 3 ‐OH) 8 (OH) 8 ] 8+ and 4‐linked [Cu 4 I 4 ] clusters [68] . The kinetics of iodine adsorption of NS‐1 was systematically studied.…”