Perfect Statistical Symmetrization of a Heterofunctional Ligand Induced by Pseudo-Copper Trimer in an Expanded Matrix of HKUST‑1

The rare coexistence of the copper monomer and paddle-wheel dimer in the same crystal framework creates an apparent linear pseudocopper trimer configuration that induces an unprecedented equalization of pyridyl and carboxyl functionality in a heterofunctional pyridyl dicarboxylate ligand, leading to an intriguing assembly into a highly symmetrical porous framework, despite the low symmetry of the ligand. The material shows a total CO₂ uptake of 55 cm³/g at 1 atm and 273 K

Perfect Statistical Symmetrization of a Heterofunctional Ligand Induced by Pseudo-Copper Trimer in an Expanded Matrix of HKUST‑1

The rare coexistence of the copper monomer and paddle-wheel dimer in the same crystal framework creates an apparent linear pseudocopper trimer configuration that induces an unprecedented equalization of pyridyl and carboxyl functionality in a heterofunctional pyridyl dicarboxylate ligand, leading to an intriguing assembly into a highly symmetrical porous framework, despite the low symmetry of the ligand. The material shows a total CO₂ uptake of 55 cm³/g at 1 atm and 273 K

Polymorphic Graphene-like Cuprous Germanosulfides with a High Cu-to-Ge Ratio and Low Band Gap

Metal chalcogenides based on heterometallic Ge–Cu–S offer dual attractive features of lattice stabilization by high-valent Ge⁴⁺ and band gap engineering into solar region by low-valent Cu⁺. Herein via cationic amine intercalation, we present three new copper-rich materials with the Cu-to-Ge ratio as high as 3. Two different patterns of Cu–Ge–S distribution could be achieved within each honeycomb sheet. The decoration of such honeycomb sheet by −Cu−S− chain or self-coupling between two honeycomb sheets leads to two layer configurations with different thickness and band gaps. The band gap of these new phases (2.06–2.30 eV), tuned by the layer thickness and the Cu/Ge ratio, represents a significant red shift over known Cu–Ge–S phases with lower Cu/Ge ratios

Luminescent <b>MTN</b>-Type Cluster–Organic Framework with 2.6 nm Cages

From a basic tetrahedral Cu₄I₄ cluster, a new <b>MTN</b>-type cluster–organic framework (<b>COZ-1</b>) containing giant 6⁴5¹² and 5¹² cages was successfully constructed. The 6⁴5¹² cage has an inner diameter of 2.6 nm and a large pore volume of 9.2 nm³; these tetrahedral Cu₄I₄ clusters with bulky size offer new opportunities for not only the formation of 4-connected zeotype structures but also the integration of porosity and photoluminescent properties from both the cluster and the framework

Luminescent <b>MTN</b>-Type Cluster–Organic Framework with 2.6 nm Cages

From a basic tetrahedral Cu₄I₄ cluster, a new <b>MTN</b>-type cluster–organic framework (<b>COZ-1</b>) containing giant 6⁴5¹² and 5¹² cages was successfully constructed. The 6⁴5¹² cage has an inner diameter of 2.6 nm and a large pore volume of 9.2 nm³; these tetrahedral Cu₄I₄ clusters with bulky size offer new opportunities for not only the formation of 4-connected zeotype structures but also the integration of porosity and photoluminescent properties from both the cluster and the framework

Direct Observation of Two Types of Proton Conduction Tunnels Coexisting in a New Porous Indium–Organic Framework

Direct Observation of Two Types of Proton Conduction Tunnels Coexisting in a New Porous Indium–Organic Framewor

Direct Observation of Two Types of Proton Conduction Tunnels Coexisting in a New Porous Indium–Organic Framework

Direct Observation of Two Types of Proton Conduction Tunnels Coexisting in a New Porous Indium–Organic Framewor

Charge-Complementary-Ligands Directed Assembly of a Lithium Dimer into a Three-Dimensional Porous Framework

Lithium ion, the first and the lightest metallic element, has the potential to generate novel materials and properties when used in the construction of metal–organic frameworks. However, so far this potential remains underexplored. Existing materials design methods developed from heavier and higher-valent elements, while extensible to other elements of the same (and perhaps higher) oxidation states are of limited value to the lithium system. To address the unique structural chemistry of monovalent lithium ion, we previously reported a method based on charge-complementary neutral and mononegative N-donor ligands in an effort to mimic ZIF-like frameworks containing monomeric lithium nodes. In this work, we demonstrate the success of this strategy beyond monomeric lithium nodes to include dimeric [Li₂]²⁺ clusters. In addition, we demonstrate the successful transitioning of this strategy away from pure N-donor-based ligand pairs into O-donor and mixed N,O-donor based ligand pairs

Design of Pore Size and Functionality in Pillar-Layered Zn-Triazolate-Dicarboxylate Frameworks and Their High CO₂/CH₄ and C2 Hydrocarbons/CH₄ Selectivity

In the design of new materials, those with rare and exceptional compositional and structural features are often highly valued and sought after. On the other hand, materials with common and more accessible modes can often provide richer and unsurpassed compositional and structural variety that makes them a more suitable platform for systematically probing the composition–structure–property correlation. We focus here on one such class of materials, pillar-layered metal–organic frameworks (MOFs), because different pore size and shape as well as functionality can be controlled and adjusted by using pillars with different geometrical and chemical features. Our approach takes advantage of the readily accessible layered Zn-1,2,4-triazolate motif and diverse dicarboxylate ligands with variable length and functional groups, to prepare seven Zn-triazolate-dicarboxylate pillar-layered MOFs. Six different gases (N₂, H₂, CO₂, C₂H₂, C₂H₄, and CH₄) were used to systematically examine the dependency of gas sorption properties on chemical and geometrical properties of those MOFs as well as their potential applications in gas storage and separation. All of these pillar-layered MOFs show not only remarkable CO₂ uptake capacity, but also high CO₂ over CH₄ and C2 hydrocarbons over CH₄ selectivity. An interesting observation is that the BDC ligand (BDC = benzenedicarboxylate) led to a material with the CO₂ uptake outperforming all other metal-triazolate-dicarboxylate MOFs, even though most of them are decorated with amino groups, generally believed to be a key factor for high CO₂ uptake. Overall, the data show that the exploration of the synergistic effect resulting from combined tuning of functional groups and pore size may be a promising strategy to develop materials with the optimum integration of geometrical and chemical factors for the highest possible gas adsorption capacity and separation performance

Systematic and Dramatic Tuning on Gas Sorption Performance in Heterometallic Metal–Organic Frameworks

Despite their having much greater potential for compositional and structural diversity, heterometallic metal–organic frameworks (MOFs) reported so far have lagged far behind their homometallic counterparts in terms of CO₂ uptake performance. Now the power of heterometallic MOFs is in full display, as shown by a series of new materials (denoted CPM-200s) with superior CO₂ uptake capacity (up to 207.6 cm³/g at 273 K and 1 bar), close to the all-time record set by MOF-74-Mg. The isosteric heat of adsorption can also be tuned from −16.4 kJ/mol for CPM-200-Sc/Mg to −79.6 kJ/mol for CPM-200-V/Mg. The latter value is the highest reported for MOFs with Lewis acid sites. Some members of the CPM-200s family consist of combinations of metal ions (e.g., Mg/Ga, Mg/Fe, Mg/V, Mg/Sc) that have never been shown to coexist in any known crystalline porous materials. Such previously unseen combinations become reality through a cooperative crystallization process, which leads to the most intimate form of integration between even highly dissimilar metals, such as Mg²⁺ and V³⁺. The synergistic effects of heterometals bestow CPM-200s with the highest CO₂ uptake capacity among known heterometallic MOFs and place them in striking distance of the all-time CO₂ uptake record