Proton conductive metal–organic frameworks based on main-group metals

Water-Mediated Proton Conduction in Metal–Organic Frameworks with High Water Stability Constructed by a Terpyridine Tricarboxylate Ligand

“…The E a > 0.5 eV of H 3 tcpb-H 2 O and 1 – 3 at low humidity indicates that the directional migration of protons mainly relies on various hydrated protons (H 3 O + ) n with the water molecules absorbed through concentration diffusion, in which this mode of proton transfer named Vehicle mechanism (>0.4 eV). , At 98% RH, the E a values are 0.31, 0.42, 0.33, and 0.34 eV for H 3 tcpb-H 2 O and 1 – 3 , respectively, indicating that these compounds have two different proton transport modes. For example, the E a values of H 3 tcpb-H 2 O , 2, and 3 at 98% RH are lower than 0.4 eV making known that protons are transferred along with the hydrogen bond networks according to the typical Grotthuss mechanism . In addition, the 0.4 < E a < 0.5 eV of 1 at 98% RH explains that proton transfer belongs to a hybrid mechanism in which the Grotthuss and vehicle mechanisms coexist .…”

“…62,63 At 98% RH, the E a values are 0.31, networks according to the typical Grotthuss mechanism. 64 In addition, the 0.4 < E a < 0.5 eV of 1 at 98% RH explains that proton transfer belongs to a hybrid mechanism in which the Grotthuss and vehicle mechanisms coexist. 65 On the one hand, protons are transferred through the H-bonding networks built by the H 2 O units entering the system and the O atoms on the −COOH that are not involved in coordination.…”

Dynamic weak coordination bonding of chlorocarbons enhances the catalytic performance of a metal–organic framework material

“…An attractive system for this study is metal–organic frameworks (MOFs), a crystalline subset of porous materials comprised of metal ions and multitopic organic linkers. Owing to the presence of permanent porosity and OMSs (in many cases), most MOFs have demonstrated salient features, playing critical roles in different applications such as drug delivery, 13–15 electronics, 16–19 ionic conduction, 20–25 chemical sensing, 26–28 molecular separation, 29–37 gas absorption, 35–47 and in particular, catalytic reactions. 47–58…”

High Protonic Conductivity of Three Highly Stable Nanoscale Hafnium(IV) Metal–Organic Frameworks and Their Imidazole-Loaded Products

“…For instance, for the MOFs with intrinsic porous structures, people are more inclined to use post-modification methods to introduce more proton carriers and proton sources into the frameworks, which offers more possibilities for improving proton conduction. To date, the strategies for boosting the σ of MOFs mainly include two types: , (1) One is to introduce small functional guest molecules (imidazole, histamine, and other nonvolatile acids) as proton carriers into the pores of MOFs; − (2) the other is to anchor free acidic functional groups (such as −COOH, −SO 3 H, or −PO 4 H 2 units) on the frameworks through chemical modification. − Summarizing the early literature, − the introduction of imidazole units into porous MOFs is a powerful tool to enhance the σ of MOFs under either humidity or anhydrous conditions. This motivated us to try to load imidazole units into Hf-based MOFs for the first time to boost their proton conductivities.…”