Jie-Peng Zhang

Metal azolate frameworks: from crystal engineering to functional materials.

2.1.2. Low Topology/Framework Density 1003 2.1.3. Side Group Directed Superstructures 1003 2.2. Synthesis Considerations 1003 2.3. Special Properties 1004 3. Metal Imidazolate Frameworks 1004 3.1. Chains and Rings 1004 3.2. Zeolitic and Zeolite-like Frameworks 1006 3.2.1. SOD-Type Zinc(II) 2-Methylimidazolate 1007 3.3. Nonporous 4-Connected Networks 1010 3.4. Polyimidazolates 1011 4. Metal Pyrazolate Frameworks 1011 4.1. Clusters and Chains 1011 4.2. 3D Networks Based on Polypyrazolates 1012 5. Metal 1,2,4-Triazolate Frameworks 1014 5.1. Simple 3-Connected Networks 1015 5.2. Quasi-Imidazolates 1018 5.3. With Coordinative Substituents 1019 5.4. With Secondary Counterions and/or Ligands 1021 6. Metal 1,2,3-Triazolate Frameworks 1023 7. Metal Tetrazolate Frameworks 1025 7.1. Univalent Coinage-Metal Tetrazolate Frameworks 1025

Supramolecular isomerism in coordination polymers

Coordination polymers have been emerging as a topical research field in crystal engineering, solid-state chemistry, and materials science. Considering the wide occurrence of structural and compositional diversity during self-assembly and crystallization, supramolecular isomerism represents an indication of composition control and structure prediction. Actually, supramolecular isomerism is not just an obstacle or challenge, but also a good opportunity for developing novel materials and a better understanding of self-assembly and crystal growth. This critical review provides an overview of the developing knowledge, in the context of supramolecular isomerism, of the design, synthesis, and properties of coordination polymers (97 references).

A Highly Connected Porous Coordination Polymer with Unusual Channel Structure and Sorption Properties

Making connections: A hydroxy-centered trinuclear nickel cluster has been employed to construct a highly connected, highly symmetric framework with a uninodal nine-connected topology. An array of triakis tetrahedra leads to a biporous intersecting-channel system (see picture).

Optimized Acetylene/Carbon Dioxide Sorption in a Dynamic Porous Crystal

The low compression limit of acetylene (C(2)H(2)) and its similarity to carbon dioxide (CO(2)) challenge the development of novel adsorbents. We illustrate in this report that the unique static and dynamic pore characteristics of a metal azolate framework, [Cu(etz)](n) (MAF-2, Hetz = 3,5-diethyl-1,2,4-triazole), can combine to show extraordinary C(2)H(2)/CO(2) sorption behaviors, which have been elucidated by a combination of gas sorption measurements and single-crystal structure analyses of the sorption complexes of both C(2)H(2) and CO(2). As demonstrated by single-crystal X-ray crystallography, C(2)H(2)/CO(2) hexamers are confined inside the nanocages of MAF-2 in different configurations. The subtle difference between C(2)H(2) and CO(2) is magnified by consequent framework dynamics, which produce sigmoid isotherms that are optimized for practical adsorptive applications. Large C(2)H(2) uptake (70 cm(3) g(-1)) and high C(2)H(2)/CO(2) uptake ratio (3.7) at 298 K, 1 atm as well as facile gas desorption are revealed. Since the C(2)H(2) uptake at 298 K, 1 atm is far from saturation (119 cm(3) g(-1)), MAF-2 permits a usable C(2)H(2) storage capacity 20 times higher than its volume or 40 times higher than that of a gas cylinder working between practical limits of 1.0-1.5 atm.

Nonclassical Active Site for Enhanced Gas Sorption in Porous Coordination Polymer

Gas sorption experiments and grand canonical Monte Carlo simulations for two isostructural microporous metal azolate frameworks show that even partially exposed uncoordinated nitrogens can effectively increase gas binding affinity and overcome the pore size confinement effect.

Strong and Dynamic CO2 Sorption in a Flexible Porous Framework Possessing Guest Chelating Claws

Using a bis-triazolate ligand and tetrahedral Zn(II) ion, we synthesized a flexible porous coordination polymer functionalized with pairs of uncoordinated triazolate N-donors that can be used as guest chelating sites to give very high CO(2) adsorption enthalpy and CO(2)/N(2) selectivity. The dynamic CO(2) sorption behavior could be monitored well by single-crystal X-ray diffraction.

Molecular chairs, zippers, zigzag and helical chains: chemical enumeration of supramolecular isomerism based on a predesigned metal-organic building-block

A predesigned metal-organic building-block [Cu(I)(2-pytz)](2-Hpytz = 3,5-di-2-pyridyl-1,2,4-triazole) has been successfully used to synthesize four genuine supramolecular isomers.

Pore Surface Tailored SOD‐Type Metal‐Organic Zeolites

Natural and synthetic zeolites are important microporous materials. [ 1 ] The highly ordered structures and tunable compositions of aluminosilicate frameworks are responsible for their extraordinary performances. After the discovery of zeolitic metal imidazolate frameworks, ranging from zeolite-like cobalt imidazolates [ 2 ] to the SOD-, ANA-, and RHO-type (three-letter codes of zeolite topologies) zinc benziimidazolate [ 3 ] and 2-alkylimidazolates, [ 4 ] these novel porous coordination polymers (PCPs) have blossomed in the past few years. [ 5 ] The similarity of the bended exo-bidentate coordination mode of imidazolate with that of the O atom in aluminosilicates has been considered as a determinative construction principle ( Figure 1 ). The rich structure-directing role of imidazolate side groups provides an additional variable for enumeration of new zeolitic structures. [ 3–5 ] Nevertheless, there seems to be some inherent difference between the inorganic and metal-organic counterparts. For example, inorganic zeolites are negatively charged aluminosilicate frameworks and their pore surface property can be routinely tailored by adjusting the Al/Si ratio and/or cation exchange. In contrast, PCPs (including metal-organic zeolites) are well-known to be completely ordered materials. Among the large family of known metal-organic zeolites, SOD-[Zn(mim) 2 ] (Hmim = 2-methylimidazole [ 4 ] ) is noteworthy for its high porosity and exceptional stability. The synthesis, porous property, sorption mechanism, and application of MAF-4 (the metal azolate framework 4) have attracted much attention. [ 6 ] However, MAF-4 only adsorbs many important gases, such as H 2 , CO 2 , and C 2 H 2 weakly, due to the lack of a strong adsorption site on its pore surface. While new functionalities of MAF-4 are still emerging, efforts have been devoted to the structural modifi cation of this prototype framework. Because imidazolates are almost the shortest linkers in PCPs, variation of the metal ion and/or substituent groups on the imidazolate linker can largely alter porosity (size or volume), change the framework, [ 5e–h ] and even alter the whole network topology. Metal ion substitution can effectively change the pore surface properties of PCPs functionalized with coordinatively unsaturated metal centers. [ 7 ] However, the tetrahedral

A porous coordination framework for highly sensitive and selective solid-phase microextraction of non-polar volatile organic compounds

A porous metal azolate framework [Zn(mpba)] (MAF-X8, H2mpba = 4-(3,5-dimethylpyrazol-4-yl)benzoic acid) with large, hydrophobic, one-dimensional channels and good thermal/chemical stability was synthesized and characterized. High-quality MAF-X8 thin films were grown on stainless-steel fibers for solid-phase microextraction (SPME), which showed high sensitivity and selectivity towards non-polar volatile organic compounds.

Geometry analysis and systematic synthesis of highly porous isoreticular frameworks with a unique topology

Porous coordination polymers are well known for their easily tailored framework structures and corresponding properties. Although systematic modulations of pore sizes of binary prototypes have gained great success, simultaneous adjustment of both pore size and shape of ternary prototypes remains unexplored, owing to the difficulty in controlling the self-assembly of multiple molecular building blocks. Here we show that simple geometry analysis can be used to estimate the influence of the linker lengths and length ratios on the synthesis/construction difficulties and framework stabilities of a highly symmetric, ternary prototype composed of a typical trinuclear metal cluster and two types of bridging carboxylate ligands. As predicted, systematic syntheses with 5×5 ligand combinations produced 13 highly porous isoreticular frameworks, which show not only systematic adjustment of pore volumes (0.49–2.04 cm3 g−1) and sizes (7.8–13.0 Å; 5.2–12.0 Å; 7.4–17.4 Å), but also anisotropic modulation of the pore shapes.