Systematic Thiol Decoration in a Redox-Active UiO-66-(SH)₂ Metal–Organic Framework: A Case Study under Oxidative and Reductive Conditions

Abstract

The practical applicability of thiolated metal–organic frameworks (MOFs) remains challenging due to their low crystallinity and transient stability. Herein, we present a one-pot solvothermal synthesis process using varying ratios of 2,5-dimercaptoterephthalic acid (DMBD) and 1,4-benzene dicarboxylic acid (100/0, 75/25, 50/50, 25/75, and 0/100) to prepare stable mixed-linker UiO-66-(SH)2 MOFs (ML-U66SX). For each variant, the effects of different linker ratios on the crystallinity, defectiveness, porosity, and particle size have been discussed in detail. In addition, the impact of modulator concentration on these features has also been described. The stability of ML-U66SX MOFs was investigated under reductive and oxidative chemical conditions. The mixed-linker MOFs were used as sacrificial catalyst supports to highlight the interplay of template stability on the rate of the gold-catalyzed 4-nitrophenol hydrogenation reaction. The release of catalytically active gold nanoclusters originating from the framework collapse decreased with the controlled DMBD proportion, resulting in a 59% drop in the normalized rate constants (9.11–3.73 s–1 mg–1). In addition, post-synthetic oxidation (PSO) was used to further probe the stability of the mixed-linker thiol MOFs under harsh oxidative conditions. Following oxidation, the UiO-66-(SH)2 MOF underwent immediate structural breakdown, unlike other mixed-linker variants. Along with crystallinity, the microporous surface area of the post-synthetically oxidized UiO-66-(SH)2 MOF could be increased from 0 to 739 m2 g–1. Thus, the present study delineates a mixed-linker strategy to stabilize the UiO-66-(SH)2 MOF under harsh chemical conditions through meticulous thiol decoration.

Spatially Confined Silver Nanoparticles in Mercapto Metal–Organic Frameworks to Compartmentalize Li Deposition Toward Anode‐Free Lithium Metal Batteries

“…[18] XPS survey spectrum of Ag@Zr-DMBD displays a strong Ag 3d signal among the other elements of C, N, O, S, and Zr shared by Zr-DMBD (Figure 1d). In the high-resolution S 2p spectra, Zr-DMBD presents only one sulfur species attributed to the free thiol (C-S-H), with its 2p 1/2 and 3/2 spin states centered at 163.6 and 162.4 eV, [19] respectively (Figure 1e). By contrast, the chemical states of sulfur in Ag@Zr-DMBD are far more complicated.…”

Disulfide‐Driven Pore Functionalization of Metal–Organic Frameworks

“…As expected, no conversion was observed for the MIL‐53(Al) system containing only terephthalic acid, and 13 % conversion was observed for MIL‐53(Al)‐(SH) 2 . It has been established that MOFs constructed from unfunctionalized linkers have higher surface areas than their functionalized analogues [17,34] . Additionally, linkers bearing bulkier functional groups have been known to restrict pore diffusion within MOFs [35] .…”

Boosting Antibacterial Photodynamic Therapy in a Nanosized Zr MOF by the Combination of Ag NP Encapsulation and Porphyrin Doping

“…UiO-66-(SH) 2 was synthesized according to the reported article with minor modification. 23 ZrCl 4 (150 mg, 0.64 mmol) and 2,5-dimercaptoterephthalic acid (70 mg, 0.30 mmol) were dissolved in 15 mL of DMF with the aid of ultrasound (10 min). Subsequently, benzoic acid (BA) (2.5 g, 20.47 mmol) was added, which was fully dissolved in the above solution under ultrasound for 10 min.…”

“…UiO-66-(SH) 2 was synthesized according to the reported article with minor modification . ZrCl 4 (150 mg, 0.64 mmol) and 2,5-dimercaptoterephthalic acid (70 mg, 0.30 mmol) were dissolved in 15 mL of DMF with the aid of ultrasound (10 min).…”