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Trigonal planar M3(O/OH) trimers are among the most important clusters in inorganic chemistry and are the foundational features of multiple high‐impact MOF platforms. Here we introduce a concept called isoreticular cluster series and demonstrate that M3(O/OH), as the first member of a supertrimer series, can be combined with a higher hierarchical member (double‐deck trimer here) to advance isoreticular chemistry. We report here an isoreticular series of pore‐space‐partitioned MOFs called M3M6pacs made from co‐assembly between M3 single‐deck trimer and M3x2 double‐deck trimer. Important factors were identified on this multi‐modular MOF platform to guide optimization of each module, which enables the phase selection of M3M6pacs by overcoming the formation of previously‐always‐observed same‐cluster phases. The new pacs materials exhibit high surface area and high uptake capacity for CO2 and small hydrocarbons, as well as selective adsorption properties relevant to separation of industrially important mixtures such as C2H2/CO2 and C2H2/C2H4. Furthermore, new M3M6pacs materials show electrocatalytic properties with high activity. [ABSTRACT FROM AUTHOR]

Multi‐module design of framework materials with multiple distinct building blocks has attracted much attention because such materials are more amenable to compositional and geometrical tuning and thus offer more opportunities for property optimization. Few examples are known that use environmentally friendly and cost‐effective solvent‐free method to synthesize such materials. Here, we report the use of solvent‐free method (also modulator‐free) to synthesize a series of multi‐module MOFs with high stability and separation property for C2H2/CO2. The synthesis only requires simple mixing of reactants and short reaction time (2 h). Highly porous and stable materials can be made without any post‐synthetic activation. The success of solvent‐free synthesis of multi‐module MOFs reflects the synergy between different modules, resulting in stable pore‐partitioned materials, despite the fact that other competitive crystallization pathways with simpler framework compositions also exist. [ABSTRACT FROM AUTHOR]

An ideal adsorbent for separation requires optimizing both storage capacity and selectivity, but maximizing both or achieving a desired balance remain challenging. Herein, a de‐linker strategy is proposed to address this issue for metal–organic frameworks (MOFs). Broadly speaking, the de‐linker idea targets a class of materials that may be viewed as being intermediate between zeolites and MOFs. Its feasibility is shown here by a series of ultra‐microporous MOFs (SNNU‐98‐M, M=Mn, Co, Ni, Zn). SNNU‐98 exhibit high volumetric C2H2 uptake capacity under low and ambient pressures (175.3 cm3 cm−3 @ 0.1 bar, 222.9 cm3 cm−3 @ 1 bar, 298 K), as well as extraordinary selectivity (2405.7 for C2H2/C2H4, 22.7 for C2H2/CO2). Remarkably, SNNU‐98‐Mn can efficiently separate C2H2 from C2H2/CO2 and C2H2/C2H4 mixtures with a benchmark C2H2/C2H4 (1/99) breakthrough time of 2325 min g−1, and produce 99.9999 % C2H4 with a productivity up to 64.6 mmol g−1, surpassing values of reported MOF adsorbents. [ABSTRACT FROM AUTHOR]

A multi‐stage core‐expansion method is proposed here as one component of the integrative binding‐site/extender/core‐expansion (BEC) strategy. The conceptual deconstruction of the partitioning ligand into three editable parts draws our focus onto progressive core expansion and allows the optimization of both acetylene uptake and selectivity. The effectiveness of this strategy is shown through a family of eight cationic pore‐partitioned materials containing three different partitioning ligands and various counter anions. The optimized structure, Co3‐cpt‐tph‐Cl (Hcpt=4‐(p‐carboxyphenyl)‐1,2,4‐triazole, H‐tph=(2,5,8‐tri‐(4‐pyridyl)‐1,3,4,6,7,9‐hexaazaphenalene) with the largest surface area and highest C2H2 uptake capacity (200 cm3/g at 298 K), also exhibits (desirably) the lowest CO2 uptake and hence the highest C2H2/CO2 selectivity. The successful boost in both C2H2 capacity and IAST selectivity allows Co3‐cpt‐tph‐Cl to rank among the best crystalline porous materials, ionic MOFs in particular, for C2H2 uptake and C2H2/CO2 experimental breakthrough separation. [ABSTRACT FROM AUTHOR]

We report here a one‐step method for synthesizing multi‐component and in‐situ‐formed homochiral spiroborate‐ester‐based metal‐organic framework CPM‐B1. This unique material successfully integrates COF fragment spiroborate ester within the MOF and simultaneously incorporate homochirality and helicity. In addition, CPM‐B1 is a rare example of framework materials that results from the cooperative assembly of three charge‐complementary cations: +1 (lithium), +2 (cobalt), and +3 (boron). The sophistication of the co‐assembly is further highlighted by the three structural roles of lithium ions. This unique structure contributes to its multi‐functional properties such as ionic conductivity and catalytic activity for oxygen reduction reaction (by CPM‐B1 carbonized material) and provides a new path to develop MOF materials with complex secondary building units and multi‐functional applications. [ABSTRACT FROM AUTHOR]

Two new rod‐packing metal–organic frameworks (RPMOF) are constructed by regulating the in situ formation of the capping agent. In CPM‐s7, carboxylate linkers extend 1D manganese‐oxide chains in four additional directions, forming 3D RPMOF. The substitution of Mn2+ with a stronger Lewis acidic Co2+, leads to an acceleration of the hydrolysis‐prone sulfonate linker, resulting in presence of sulfate ions to reduce two out of the four carboxylate‐extending directions, and thus forming a new 2D rod‐packing CPM‐s8. Density functional theory calculations and magnetization measurements reveal ferrimagnetic ordering of CPM‐s8, signifying the potential of exploring 2D RPMOF for effective low‐dimensional magnetic materials. [ABSTRACT FROM AUTHOR]

Nonprecious transition metal‐organic frameworks (MOFs) are one of the most promising precursors for developing electrocatalysts with high porosity and structural rigidity. This study reports the synthesis of high efficiency electrocatalysts based on S‐doped NiFeP. MOF‐derived S‐doped NiFeP structure is synthesized by a one‐step phosphorization process with using S‐doped MOFs as the precursor, which is more convenient and environment friendly, and also helps retain the samples' framework. The oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) performance of the NiFeP catalysts can be improved after partially replacing P by S due to the tunable electronic structure. The optimized CCS‐NiFeP‐10 reaches a current density of 10 mA cm–2 for OER with an overpotential of 201 mV and outperforms most NiFe‐based catalysts. The S doping plays an important role in tuning the ΔG values for intermediates formation in Ni atoms to a suitable value and exhibits a pronouncedly improved the OER performance. CCS‐NiFeP‐20 sample presents excellent HER performance due to the d‐band center downshifting from the Fermi level. When the voltage of the electrolytic cell is 1.50 V, a current density of 10 mA cm–2 can be obtained. This strategy paves the way for designing highly active none‐noble metal catalysts. [ABSTRACT FROM AUTHOR]

Author(s): Nanfeng Zheng [1]; Xianhui Bu [2, 3]; Pingyun Feng (corresponding author) [1] Natural porous solids such as zeolites are invariably formed with inorganic cations such as Na[sup.+] and K[sup.+] [...]

We report here a strategy for making anionic pacs type porous materials by combining pore space partition with charge reallocation. The method uses the first negatively charged pore partition ligand (2,5,8‐tri‐(4‐pyridyl)‐1,3,4,6,7,9‐hexaazaphenalene, H‐tph) that simultaneously enables pore partition and charge reallocation. Over two dozen anionic pacs materials have been made to demonstrate their excellent chemical stability and a high degree of tunability. Notably, Ni3‐bdt‐tph (bdt=1,4‐benzeneditetrazolate) exhibits month‐long water stability, while CoV‐bdt‐tph sets a new benchmark for C2H2 storage capacity under ambient conditions for ionic MOFs. In addition to tunable in‐framework modules, we show feasibility to tune the type and concentration of extra‐framework counter cations and their influence on both stability and capability to separate industrial C3H8/C3H6 and C6H6/C6H12 mixtures. [ABSTRACT FROM AUTHOR]

Metal chalcogenide supertetrahedral clusters (MCSCs) are of significance for developing crystalline porous framework materials and atomically precise cluster chemistry. Early research interest focused on the synthetic and structural chemistry of MCSC-based porous semiconductor materials with different cluster sizes/compositions and their applications in adsorption-based separation and optoelectronics. More recently, focus has shifted to the cluster chemistry of MCSCs to establish atomically precise structure–composition–property relationships, which are critical for regulating the properties and expanding the applications of MCSCs. Importantly, MCSCs are similar to II–VI or I–III–VI semiconductor nanocrystals (also called quantum dots, QDs) but avoid their inherent size polydispersity and structural ambiguity. Thus, discrete MCSCs, especially those that are solution-processable, could provide models for understanding various issues that cannot be easily clarified using QDs. This review covers three decades of efforts on MCSCs, including advancements in MCSC-based open frameworks (reticular chemistry), the precise structure–property relationships of MCSCs (cluster chemistry), and the functionalization and applications of MCSC-based microcrystals. An outlook on remaining problems to be solved and future trends is also presented. [ABSTRACT FROM AUTHOR]

High gas‐uptake capacity is desirable for many reasons such as gas storage and sequestration. Moreover, ultrahigh capacity can enable a practical separation process by mitigating the selectivity factor that sometimes compromises separation efficiency. Herein, a single‐walled nickel–organic framework with an exceptionally high gas capture capability is reported. For example, C2H4 and C2H6 uptake capacities are at record‐setting levels of 224 and 289 cm3 g−1 at 273 K and 1 bar (169 and 110 cm3 g−1 at 298 K and 1 bar), respectively. Such ultrahigh capacities for both gases give rise to an excellent separation performance, as shown for C2H6/C2H4 with breakthrough times of 100, 60 and 30 min at 273, 283 and 298 K and under 1 atm. This new material is also shown to readily remove ethylene released from fruits, and once again, its ultrahigh capacity plays a key role in the extraordinary length of time achieved in the preservation of the fruit freshness. [ABSTRACT FROM AUTHOR]

For rare‐earth separation, selective crystallization into metal‐organic frameworks (MOFs) offers new opportunities. Especially important is the development of MOF platforms with high selectivity toward target ions. Here we report a MOF platform (CPM‐66) with low‐coordination‐number environment for rare‐earth ions. This platform is highly responsive to the size variation of rare‐earth ions and shows exceptional ion‐size selectivity during crystallization. CPM‐66 family are based on M3O trimers (M=6‐coordinated Sc, In, Er‐Lu) that are rare for lanthanides. We show that the size matching between urea‐type solvents and metal ions is crucial for their successful synthesis. We further show that CPM‐66 enables a dramatic multi‐fold increase in separation efficiency over CPM‐29 with 7‐coordinated ions. This work provides some insights into methods to prepare low‐coordinate MOFs from large ions and such MOFs could serve as high‐efficiency platforms for lanthanide separation, as well as other applications. [ABSTRACT FROM AUTHOR]

Introduction of pore partition agents into hexagonal channels of MIL‐88 type (acs topology) endows materials with high tunability in gas sorption. Here, we report a strategy to partition acs framework into pacs (partitioned acs) crystalline porous materials (CPM). This strategy is based on insertion of in situ synthesized 4,4′‐dipyridylsulfide (dps) ligands. One third of open metal sites in the acs net are retained in pacs MOFs; two thirds are used for pore‐space partition. The Co2V‐pacs MOFs exhibit near or at record high uptake capacities for C2H2, C2H4, C2H6, and CO2 among MOFs. The storage capacity of C2H2 is 234 cm3 g−1 (298 K) and 330 cm3 g−1 (273 K) at 1 atm for CPM‐733‐dps (the Co2V‐BDC form, BDC=1,4‐benzenedicarboxylate). These high uptake capacities are accomplished with low heat of adsorption, a feature desirable for low‐energy‐cost adsorbent regeneration. CPM‐733‐dps is stable and shows no loss of C2H2 adsorption capacity following multiple adsorption–desorption cycles. [ABSTRACT FROM AUTHOR]

Introduction of pore partition agents into hexagonal channels of MIL‐88 type (acs topology) endows materials with high tunability in gas sorption. Here, we report a strategy to partition acs framework into pacs (partitioned acs) crystalline porous materials (CPM). This strategy is based on insertion of in situ synthesized 4,4′‐dipyridylsulfide (dps) ligands. One third of open metal sites in the acs net are retained in pacs MOFs; two thirds are used for pore‐space partition. The Co2V‐pacs MOFs exhibit near or at record high uptake capacities for C2H2, C2H4, C2H6, and CO2 among MOFs. The storage capacity of C2H2 is 234 cm3 g−1 (298 K) and 330 cm3 g−1 (273 K) at 1 atm for CPM‐733‐dps (the Co2V‐BDC form, BDC=1,4‐benzenedicarboxylate). These high uptake capacities are accomplished with low heat of adsorption, a feature desirable for low‐energy‐cost adsorbent regeneration. CPM‐733‐dps is stable and shows no loss of C2H2 adsorption capacity following multiple adsorption–desorption cycles. [ABSTRACT FROM AUTHOR]

Although many rod‐packing metal‐organic frameworks are known, few are based on ordered heterometallic rod building unit. We show here the synthesis of CPM‐76 based on an unprecedented Zn‐Mg bimetallic rod with crystallographically distinguishable metal sites. The configuration of the rod offers two types of coordination site with trigonal bipyramidal and octahedral sites selectively occupied by Zn and Mg, respectively. Also unusual is the inter‐connection mode between the rods, which is based on dual‐charged forms (−3 and −2) of the 2‐hydroxyterephthalic acid (H3OBDC) ligand. Interestingly, each metal site in CPM‐76 binds one solvent molecule, leading to a high density of solvent binding sites. [ABSTRACT FROM AUTHOR]

Low-cost Ni(OH)2-based nanomaterials with various structures and morphologies are promising catalysts for efficient oxygen evolution reactions (OERs). However, homogenous Ni(OH)2 nanomaterials with abundant active sites suffer from low conductivity and easy aggregation, resulting in low catalytic activity and stability. Here, we report a new synthetic method capable of generating abundant and confined S-doped β-Ni(OH)2 nanoparticles (NPs) (3–5 nm) within a 3D semiconductor substrate, metal-chalcogenide semiconductor zeolite (CSZ). This method operates via sequential fluoride-assisted cationic stripping and in situ Ni(OH)2 generation and is demonstrated here as an effective method to synthesize Ni2+-containing CSZ that are known to defy direct synthesis. The resulting composite (denoted Ni(OH)2 NPs@CSZ) exhibited excellent OER performance with a very low overpotential of only 212 mV at a current density of 10 mA cm−2 in O2-saturated 1 M KOH solution, and low Tafel slope of 64.2 mV dec−1, which is superior to that of benchmark IrO2. DFT calculations indicate that the interaction between the embedded Ni(OH)2 NPs and the dopant, S2−, from the host CSZ played a crucial role in improving OER performance. This work provides a new path for developing high-performance Ni(OH)2-based OER catalysts and may also serve as a general approach for loading large amounts of other catalytically active NPs into semiconducting open frameworks to further optimize electrocatalytic performance. [ABSTRACT FROM AUTHOR]

Zeolitic imidazolate frameworks (ZIFs) are traditionally synthesized solvothermally by using cost‐ and waste‐incurring organic solvents. Here, a direct synthesis method is reported for ZIF‐8, ZIF‐67, and their heterometallic versions from solid precursors only. This solvent‐free crystallization method not only completely avoids organic solvents, but also provides an effective path for the synthesis of homogeneous mixed‐metal ZIFs. Furthermore, under templating by NaCl/ZnCl2 eutectic salt, carbonization of the ZIF materials gives rise to a series of N‐containing high‐surface‐area carbon materials with impressive catalytic properties for the oxygen reduction reaction. [ABSTRACT FROM AUTHOR]

Research has been conducted on chromium(III) complexes. The authors describe the synthesis of these complexes carried out by utilizing derivatives of the macrocyclic ligand cyclam 1,4,8,11-tetraazacyclotetradecane with N-substituted chromophores.

A strategy called ultramicroporous building unit (UBU) is introduced. It allows the creation of hierarchical bi‐porous features that work in tandem to enhance gas uptake capacity and separation. Smaller pores from UBUs promote selectivity, while larger inter‐UBU packing pores increase uptake capacity. The effectiveness of this UBU strategy is shown with a cobalt MOF (denoted SNNU‐45) in which octahedral cages with 4.5 Å pore size serve as UBUs. The C2H2 uptake capacity at 1 atm reaches 193.0 cm3 g−1 (8.6 mmol g−1) at 273 K and 134.0 cm3 g−1 (6.0 mmol g−1) at 298 K. Such high uptake capacity is accompanied by a high C2H2/CO2 selectivity of up to 8.5 at 298 K. Dynamic breakthrough studies at room temperature and 1 atm show a C2H2/CO2 breakthrough time up to 79 min g−1, among top‐performing MOFs. Grand canonical Monte Carlo simulations agree that ultrahigh C2H2/CO2 selectivity is mainly from UBU ultramicropores, while packing pores promote C2H2 uptake capacity. [ABSTRACT FROM AUTHOR]

Embedding cubane [M4(OH)4] (M=Ni, Co) clusters within the matrix of metal–organic frameworks (MOFs) is a strategy to develop materials with unprecedented synergistic properties. Herein, a new material type based on the pore‐space partition of the cubic primitive minimal‐surface net (MOF‐14‐type) has been realized. CTGU‐15 made from the [Ni4(OH)4] cluster not only has very high BET surface area (3537 m2 g−1), but also exhibits bi‐microporous features with well‐defined micropores at 0.86 nm and 1.51 nm. Furthermore, CTGU‐15 is stable even under high pH (0.1 m KOH), making it well suited for methanol oxidation in basic medium. The optimal hybrid catalyst KB&CTGU‐15 (1:2) made from ketjen black (KB) and CTGU‐15 exhibits an outstanding performance with a high mass specific peak current of 527 mA mg−1 and excellent peak current density (29.8 mA cm−2) at low potential (0.6 V). The isostructural cobalt structure (CTGU‐16) has also been synthesized, further expanding the application potential of this material type. [ABSTRACT FROM AUTHOR]

We report a new magnesium metal–organic framework (MOF) (CPM‐107) with a special interaction with CO2. CPM‐107 contains Mg2‐acetate chains crosslinked into a 3D net by terephthalate. It has an anionic framework encapsulating ordered extra‐framework cations and solvent molecules. The desolvated form is closed and unresponsive to common gasses, such as N2, H2, and CH4. Yet, with CO2 at 195 K, it abruptly opens and turns into a rigid porous form that is irreversible via desorption. Once opened by CO2, CPM‐107 remains in the stable porous state accessible to additional gas types over multiple cycles or CO2 itself at different temperatures. The porous phase can be re‐locked to return to the initial closed phase via re‐solvation and desolvation. Such peculiar properties of CPM‐107 are apparently linked to a convergence of factors related to both framework and extra‐framework features. The unusual CO2 effect is currently the only available path to porous CPM‐107 which shows efficient C2H2/CO2 separation. [ABSTRACT FROM AUTHOR]