Controlling the molecular diffusion in MOFs with the acidity of monocarboxylate modulators

Abstract

The catalytic performance of metal-organic frameworks (MOFs) is related to their physicochemical properties, such as particle size, defect-chemistry and porosity, which synthetic control can be potentially achieved by coordination modulation....

Understanding the Role of Synthetic Parameters in the Defect Engineering of UiO-66: A Review and Meta-analysis

“…Additionally, we narrowed the focus to UiO-66 without functionalization or any kind of postsynthetic modification, as well as excluding UiO-66 analogues such as UiO-67. The final data set (included in the Supporting Information) is intended to be a representative, but not a comprehensive summary of the current literature and comprises of 293 samples across 37 papers, ,,,− ,,,− representing a publication period from 2011 to 2022. The distribution of the data set across input and output variables is also presented in the Supporting Information.…”

“…The aim of this review is to draw connections between synthetic parameters and the final defective structures reported in the literature to aid the experimental design of UiO-66 MOFs with specific defect properties; it is expected that other MOFs with similarly strong coordination bonds will have similar dependence on synthetic parameters. To assist with this goal, we conducted a literature meta-analysis with 293 samples across 37 papers ,,,− ,,,− looking for reliable trends between reaction parameters and structural outcomes, such as defect concentration. We fit a LASSO linear regression model relating the synthetic parameters studied (time, temperature, and reagent concentrations) to quantitative defectivity and other output variables.…”

Effect of the Defect Modulator and Ligand Length of Metal–Organic Frameworks on Carbon Dioxide Photoreduction

“…The molar equivalents of the modulators are all 30 with respect to the dicarboxylate links in the synthetic process, and the results of 1 H NMR analysis and the thermogravimetric analysis–differential thermogravimetric analysis (TGA–DTG) data (Figure S9) of UiO-68-NH 2 -BA and UiO-68-NH 2 -2ABA, UiO-67-NH 2 -BA and UiO-67-NH 2 -2ABA, and UiO-66-NH 2 -BA and UiO-66-NH 2 -2ABA sets verify that the defect degrees of these MOFs are influenced by the amino groups in benzoic acid. The benzoic acid with an amino group reduces the degree of defects per node compared to that produced by the benzoic acid in MOFs, which is due to its less acidic property and enhanced steric hindrance compared to that of the dicarboxylate linkers . It is noteworthy that the amino groups in the defects heighten the surface area and the capacity of CO 2 adsorption; for instance, the Brunauer–Emmett–Teller surface area and CO 2 adsorption capacity (Figure S10) for UiO-66-NH 2 -BA and UiO-66-NH 2 -2ABA samples increase from 593.81 to 740.24 m 2 g –1 and 13.18 to 47.46 cm 3 g –1 (at 298 K), respectively, with the same trends as that of sets UiO-68-NH 2 -BA and UiO-68-NH 2 -2ABA and UiO-67-NH 2 -BA and UiO-67-NH 2 -2ABA (Table S1).…”

“…The benzoic acid with an amino group reduces the degree of defects per node compared to that produced by the benzoic acid in MOFs, which is due to its less acidic property and enhanced steric hindrance compared to that of the dicarboxylate linkers. 35 It is noteworthy that the amino groups in the defects heighten the surface area and the capacity of CO 2 adsorption; for instance, the Brunauer−Emmett−Teller surface area and CO 2 adsorption capacity (Figure S10) for UiO-66-NH 2 -BA and UiO-66-NH 2 -2ABA samples increase from 593.81 to 740.24 m 2 g −1 and 13.18 to 47.46 cm 3 g −1 (at 298 K), respectively, with the same trends as that of sets UiO-68-NH 2 -BA and UiO-68-NH 2 -2ABA and UiO-67-NH 2 -BA and UiO-67-NH 2 -2ABA (Table S1). Though the samples of UiO-68-NH 2 -2ABA, UiO-67-NH 2 -2ABA, and UiO-66-NH 2 -2ABA…”

MOF nanoparticles as heterogeneous catalysts for direct amide bond formations

“…[17][18][19][20][21] Among all the metals employed in the synthesis of robust and active MOFbased catalysts, Zr(IV) MOFs such as the UiO family or MOF-808, which contain Zr 6 O 4 (OH) 4 (RCO 2 ) 12 clusters, have been widely applied for the activation of carbonyls or other oxo-functions due to the presence of highly oxophilic coordinatively unsaturated sites (CUS). [22][23][24][25] These MOFs are also the preferred systems in acid-catalyzed direct amidation reactions between carboxylic acids and amines. [26][27][28] On the one hand, Timofeeva et al considered either the sulphated cluster or the pore sizein the case of sulfonated MOF-808 or UiO-66, respectively 27 as key factors for the formylation of aniline under solvent-free/MeOH room temperature conditions (see Scheme 1a).…”