Two Water-Stable Silver–Sulfur MOFs with Interesting Topology: High-Performance H<sub>2</sub>S Adsorption and Record-Breaking Iodine Uptake
Maryam Bahrani‐Pour, Azizolla Beheshti, Tahereh Sedaghat, Sepideh Samiee, Hassan Arefi-Nasab, Pengbo Lyu, Péter Mayer, Emmanuele Parisi
Abstract
Sulfur-based coordination polymers have gained significant attention, yet constructing 3D sulfur-based networks remains challenging. This study presents two novel 3D water-stable silver–sulfur MOFs: { [Ag 6 Cl 2 (L 3 ) 5 ][BF 4 ] 4 } n (SCU-1) and [AgSCN(L 3 )] n (SCU-2) . Single crystals were synthesized using the branched tube method, and X-ray crystallography revealed SCU-1’s large cationic framework with 193 atoms per unit cell and a volume of ∼10,000 Å 3, exhibiting 15.1% porosity. SCU-2, with a simpler structure, showed 5.9% porosity. Leveraging the strong silver–sulfur affinity and the methimazole-based ligands’ potential for iodine uptake, the iodine adsorption capabilities of SCU-1 and SCU-2 were investigated, revealing remarkable uptake capacities of 3.650 g/g and 3.749 g/g, respectively, setting a new benchmark for iodine removal. Additionally, the H 2 S adsorption potential of these frameworks was explored for the first time. SCU-1, with BF 4 – and Cl – as electron-rich sites, exhibited a higher H 2 S adsorption energy ( E ads = −45.0 kJ mol –1 ) compared to SCU-2 ( E ads = −39.0 kJ mol –1 ), where thiocyanate serves as the electron-rich component. Simulations aligned well with experimental data, highlighting the frameworks’ potential for gas adsorption applications. This work advances the design of sulfur-based MOFs for environmental remediation, particularly in iodine and H 2 S capture.