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High storage capacity, high separation selectivity, and high structure stability are essential for an idea gas adsorbent. However, it is not easy to achieve all three at the same time, even for the promising metal-organic framework (MOF) adsorbents. We demonstrate herein that robust [Sc 3 O]-organic frameworks could be regulated by a micropore combination strategy for high-performance acetylene adsorption. Under the same solvent system with formic acid as a modulator, similar tritopic ligands extend [Sc 3 O(COO) 6 ] trigonal-prismatic clusters to generate SNNU-5-Sc and SNNU-150-Sc adsorbents. Notably, the two Sc-MOFs can keep their architectures over 24 h in water at different pH values (2-12) or at 90 °C. Modulated by the linker symmetry, the final stacking metal-organic polyhedral cages produce open window sizes of about 10 Å for SNNU-5-Sc and 5 Å + 7 Å for SNNU-150-Sc. Due to such micropore combinations, SNNU-5-Sc exhibits a top-level C 2 H 2 uptake of 211.2 cm 3 g -1 (1 atm and 273 K) and SNNU-150-Sc shows high C 2 H 2 /CH 4 , C 2 H 2 /C 2 H 4 , and C 2 H 2 /CO 2 selectivities of 80.65, 4.03, and 8.19, respectively, under ambient conditions. Dynamic breakthrough curves obtained on a fixed-bed column and grand canonical Monte Carlo (GCMC) simulations further support their prominent acetylene storage and purification performance. High framework stability, storage capacity, and separation selectivity make SNNU-5-Sc and SNNU-150-Sc ideal acetylene adsorbents in practical applications.

The construction of superstable metal-organic frameworks (MOFs) for selective gas uptake is urgently demanded but remains a great challenge. Herein, a unique bifunctional deformed [Ga 3 O(COO) 6 ] inorganic secondary building unit (SBU) generated from the desymmetrical evolution of typical triangular prismatic trinuclear cluster was first introduced, which was extended by an isosceles triangular organic linker to produce a robust Ga-MOF ( SNNU-63 ). Remarkably, SNNU-63 can stabilize in water at 25 °C for 96 h and at 80 °C for more than 24 h, which surpasses nearly all other Ga-MOFs. The combined effects of open metal sites and hydrophobic pore environment provided by deformed [Ga 3 O] SBUs render SNNU-63 with high C 2 H 2 storage capacity and efficient C 2 H 2 and natural gas purification performance. The ideal adsorbed solution theory calculation, column breakthrough tests, and grand canonical Monte Carlo simulations demonstrate that SNNU-63 is a potential material for addressing the challenge of C 2 H 2 /CO 2 and C 2 H 2 /CH 4 mixture separation under ambient conditions.

The separation of a mixture of C 2 H 2 and CO 2 is a great challenge due to their similar molecular sizes and shapes. Al-based metal-organic frameworks (Al-MOFs) have great promise for gas separation applications due to their light weight, high stability, and low cost. However, the cultivation of suitable Al-MOF single crystals is extremely difficult and has limited their explorations up to now. Since In, Ga, and Al are all 3p-block metal elements, a systematic application of the periodic law to investigate 3p-MOFs will undoubtedly help in the understanding and development of worthy Al-MOF materials. Herein, we report the design of a robust 3p metal-organic framework platform (SNNU-150) and the systematic regulation of C 2 H 2 /CO 2 separation by open 3p-block metal sites. X-ray single-crystal diffraction analysis reveals that SNNU-150 is a 3,6-connected 3D framework consisting of [M 3 O(COO) 6 ] trinuclear secondary building units (SBUs) and tritopic nitrilotribenzoate (NTB) linkers. Small {[M 3 O(COO) 6 ] 4 (NTB) 6 } tetrahedral cages and extra-large {[M 3 O(COO) 6 ] 10 (NTB) 14 } polyhedral cages connect with each other to generate a hierarchically porous architecture. These 3p-MOFs present very high water, thermal, and chemical stability, especially for SNNU-150-Al, which can maintain its framework at 85 °C in water for 24 h and in a room-temperature environment for more than 30 days. IAST calculations, breakthrough experiments, and GCMC simulations all show that SNNU-150 MOFs have top-level C 2 H 2 /CO 2 separation performance and follow the order Al-MOF > Ga-MOF > In-MOF.

Evaluating the effect of ligand substitution on metal ions and/or clusters during the MOF growth process is conducive to rational design of isoreticular MOFs with improved performance. Through topological direction and ligand substitution strategy, we herein constructed two Sc-soc-MOFs ( Sc-EBTC and Sc-ABTC ) based on two similar rectangular-planar diisophthalate ligands, linear-shaped H 4 EBTC (1,1'-ethynebenzene-3,3',5,5'-tetracarboxylic acid) and zigzag-shaped H 4 ABTC (3,3',5,5'-azobenzenetetracarboxylic acid), under solvothermal conditions with formic acid as a modulator. {Sc[(Sc 3 O)(H 2 O) 3 ] 3 (EBTC) 6 } ( Sc-EBTC ) possesses two distinct clusters as SBUs, trinuclear [Sc 3 O(CO 2 ) 6 ] (SBU1) and mononuclear cluster [ScO 6 ] (SBU2), which maintain the soc-topology except for the mononuclear [ScO 6 ] instead of the corresponding trinuclear [Sc 3 O(CO 2 ) 6 ] in Sc-ABTC ({(Sc 3 O)(H 2 O) 3 (ABTC) 1.5 (NO 3 )}). Notably, Sc-EBTC represents a rare soc-MOF with two distinct clusters as SBUs. Due to similar pore spaces, the two Sc-soc-MOF materials both exhibit enhanced and comparable gas sorption and selectivity performances. Specially, their remarkable C 2 H 2 , C 2 H 4 , and CO 2 storage capacity along with prominent CO 2 /CH 4 and C 2 -hydrocarbons/CH 4 separations indicate that these Sc-soc-MOFs are promising adsorbents for natural gas purification under ambient conditions.

The concept of high-performance excited-state intramolecular proton transfer (ESIPT)-based fluorescent metal-organic framework (MOF) probes for Al 3+ is proposed in this work. By regulating the hydroxyl groups on the organic linker step by step, new fluorescent magnesium-organic framework (Mg-MOF) probes for Al 3+ ions were established based on the ESIPT fluorescence mechanism. It is observed for the first time that the number of intramolecular hydrogen bonds between adjacent hydroxyl and carboxyl groups can effectively adjust the ESIPT process and lead to tunable fluorescence sensing performance. Together with the well-designed porous and anionic framework, the Mg-TPP-DHBDC probe decorating with a pair of intramolecular hydrogen bonds exhibits extra-high quantitative fluorescence response to Al 3+ through an unusual turn-off (0-1.2 μM) and turn-on (4.2-15 μM) luminescence sensing mechanism. Notably, the 28 nM limit of detection value represents the lowest record among all reported MOF-based Al 3+ fluorescent sensors up to now. Benefited from the unique turn-off-on ESIPT fluorescence detection process, the Mg-TPP-DHBDC MOF sensor exhibits single Al 3+ detection compared with other 16 common metal ions including Ga 3+ , In 3+ , Fe 3+ , Cr 3+ , Ca 2+ , and Mg 2+ . Impressively, such an Al 3+ selective sensing process can even be fulfilled by the reusable MOF test paper detected by naked eyes. Overall, the quantitative Al 3+ detection, together with the extraordinary sensitivity, selectivity, fast response, and good reusability, strongly supports our concept of ESIPT-based fluorescent MOF Al 3+ probes and makes Mg-TPP-DHBDC one of the most powerful Al 3+ fluorescent sensors.

A general preparative method for multifunctional halogeno(cyano)cuprate materials in ionic liquids is developed in this work. Under ionothermal conditions, alkylimidazolium-based ionic liquids serving as solvent, charge-compensating, and structure-directing agent, as well as reactant lead to 12 members of the novel hybrid halogeno(cyano)cuprate family with a general formula of [R 1 R 2 R 3 IM] b+c-a [Cu a X b (CN) c ] (R 1 R 2 R 3 IM = alkylimidazolium cations, X = halide anions). X-ray single-crystal diffractions show that diverse inorganic halogeno(cyano)cuprate components vary from discrete complexes (1 and 2), one-dimensional (1D) chains (3-7), two-dimensional (2D) layer (8), to three-dimensional (3D) open frameworks (9-12). 1 and 2 are of zero-dimensional discrete structures containing triangular [CuX 3 ] 2- anions. In complexes 3-7, pentagonal bipyramidal [Cu 2 X 3 ] units are bridged by CN groups to give 1D [Cu 2 X 3 (CN)] 2- inorganic chains, which are charge-balanced by the surrounded alkylimidazolium cations. 2D inorganic [Cu 5 ClI 2 (CN) 4 ] 2- layer in complex 8 is alternately packed with [VMIM] + organic cations. In complex 9, left- and right-handed Cu-CN helical chains connect each other to give a 3D open framework, which are further entrapped by 1D zigzag Cu-CN chains and [PMIM] + cations. Diverse unique Cu(I) atoms and cyanide or halide bridging groups in 10, 11, and 12 are extended into 3D anionic open frameworks with 1D channels, which are occupied by alkylimidazolium cations. For all hybrid halogeno(cyano)cuprate complexes, the extensively existing C-H···X or C-H···π hydrogen bonds help to stabilize the ultimate supramolecular packing structures. Notably, the distances between adjacent Cu(I) centers range from 2.420(2) to 2.989(2) Å in all polymeric frameworks, which indicate strong Cu···Cu interactions. Thanks to the cooperation of conjugate π electron cyanide systems with halide ions and/or Cu···Cu interactions, compounds 1-12 all demonstrate strong solid-state photoluminescence and semiconducting performance. Specially, hybrid halogeno(cyano)cuprates reported herein first exhibit excellent photocatalytic degradation of organic dye. To the best of our knowledge, fewer than 10 crystalline halogeno(cyano)cuprate compounds were obtained before this work, although different synthetic routes have been involved. Clearly, the discovery of this large hybrid material family under ionothermal conditions is important for the further development of novel functional halogeno(cyano) filled-shell d 10 metal crystalline materials.

Reported herein is a novel porous metal-organic framework (MOF) exhibiting unique nanoscale cages derived from the 3-fold self-interpenetration of chiral eta networks based on trifurcate {Zn2(CO2)3} building blocks and 1,3,5-tris(4-carboxyphenyl)benzene ligands. The attractive self-interpenetrated structural features contribute to the highest CO2 uptake capacity and CO2 binding ability among the interpenetrated MOFs.

This work focused on a systematic investigation of the influences of the spacer length of the flexible alpha,omega-bis(benzotriazole)alkane ligands and counteranions on the overall molecular architectures of hybrid structures that include Cu(I). Using the self-assembly of CuX (X = Cl, Br, I, or CN) with the five structurally related flexible organic ligands (L1-L5) under hydro(solvo)thermal conditions, we have synthesized and characterized 10 structurally unique materials of the Cu(I)/X/alpha,omega-bis(benzotriazole)alkane organic-inorganic hybrid family, {[CuCl](2)(L1)}(n) (1), {[CuBr](L2)}(n) (2), {[CuCl](2)(L3)}(n) (3), {[CuI](2)(L4)}(n) (4), {[CuBr](2)(L4)}(n) (5), {[CuBr](3)(L5)}(n) (6), {[CuCN](2)(L1)}(n) (7), {[CuCl](4)(L2)}(n) (8), {[CuBr](4)(L2)}(n) (9), and {[CuCl](2)(L4)}(n) (10), by means of elemental analyses, X-ray powder diffraction, Fourier transform infrared spectroscopy, thermogravimetric analysis, and photoluminescence measurements. Single-crystal X-ray analyses showed that the inorganic subunits in these compounds were {Cu(2)X(2)} binuclear clusters (1 and 2), {Cu(4)X(4)} cubane clusters (4, 5, and 10), {CuX}(n) single chains (3 and 7), a {Cu(3)X(3)}(n) ladderlike chain (6), and unprecedented {Cu(8)X(8)}(n) ribbons (8 and 9). The increasing dimensionality from 1-D (1-4) to 2-D (5 and 6) to 3-D (7-10) indicates that the spacer length and isomerism of the bis(benzotriazole)alkane ligands play an essential role in the formation of the framework of the Cu(I) hybrid materials. The influence of counteranions and pi-pi stacking interactions on the formation and dimensionality of these hybrid coordination polymers has also been explored. In addition, all the complexes exhibit high thermal stability and strong fluorescence properties in the solid state at ambient temperature.