Metal-organic frameworks based upon non-zeotype 4-connected topology

Pillar-layered metal–organic frameworks (MOFs) are among the most interesting research areas in crystalline materials. Due to the great number of reports related to pillar-layered MOFs, investigating their structural diversity, properties and applicability as multi-donor porous frameworks is of great interest. Modifying pillar moieties as a third building block of pillar-layered MOFs, together with metal nodes and oxygen donor linkers, can enhance control of the structure assembly, leading to specific properties of the obtained structures. Although the past decade has witnessed remarkable advances in this research area, pillar-layered MOFs have not been reviewed as an independent subject to date. Therefore, a review summarizing their performance is greatly needed. This review covers issues related to pillar-layered MOFs, including their structural properties, synthesis, stability, diversity of linkers, and improved applicability. Finally, pillar linkers are studied separately according to their diverse donor atoms and functional groups.

Pillar-layered MOFs: Functionality, Interpenetration, Flexibility and Applications

We report the synthesis, structure, and characterization of two novel porous zeolite-like supramolecular assemblies, ZSA-1 and ZSA-2, having zeolite gis and rho topologies, respectively. The two compounds were assembled from functional metal-organic squares (MOSs) via directional hydrogen-bonding interactions and exhibited permanent microporosity and thermal stability up to 300 °C.

From Metal−Organic Squares to Porous Zeolite-like Supramolecular Assemblies

The hydrothermal reactions of lanthanide salts with substituted imidazole-4,5-dicarboxylic acids in the presence of aliphatic carboxylates afforded a new family of lanthanide metal–organic frameworks formulated as {Y3[(Heimda)4(μ2-HCOO)·3H2O]·H2O}n (1Y), {[Gd3(Heimda)4(μ2-HCOO)·4H2O]·2H2O}n (2Gd), {[Tb3(Heimda)4(μ2-HCOO)·4H2O]·2H2O}n (3Tb) and {[Nd3(Hpimda)2(μ2-HCOO) (μ2 -C2O4)2·6H2O]·4H2O}n (4Nd), (H3eimda = 2-ethyl-1H-imidazole-4,5-dicarboxylic acid, while H3pimda = 2-propyl-1H-imidazole-4,5-dicarboxylic acid). The structural diversity and photophysical and magnetic properties have been investigated. The polymer 3 triggers intense characteristic lanthanide-centered green luminescence under UV excitation, and it exhibits gradually increasing luminescence intensities when dispersed in water, ethanol, and DMSO as suspensions. After water molecules are liberated from the condensed frameworks of 4, the evacuated product (4a) exhibits nitrogen sorption properties at 77 K with a hysteresis, as well as strong c...

From Two-Dimensional Double Decker Architecture to Three-Dimensional pcu Framework with One-Dimensional Tube: Syntheses, Structures, Luminescence, and Magnetic Studies

This work presents two unique entangled coordination polymers based on square Cd4-building blocks. Complex 1 represents the first example of 2D→ 3D parallel polycatenated architecture constructed from a 4·82-fes net, whereas complex 2 shows an unusual (3,4)-connected self- catenated network that can be viewed as the cross-linking of a 2D + 2D→3D inclined polycatenation.

Two Unique Entangling CdII-Coordination Frameworks Constructed by Square Cd4-Building Blocks and Auxiliary N,N′-Donor Ligands

Four novel complexes, {[Ni4(HEIDC)4(H2O)8]·2H2O} (1), {[Mn(HEIDC)(4,4′-bipy)0.5(H2O)]·H2O}n (2), [Mn6(EIDC)4(py)(H2O)4]n (3), and {[Cd2(EIDC)(H2EIDC)(4,4′-bipy)1.5]·H2O}n (4) (H3EIDC = 2-ethyl-1H-imidazole-4,5-dicarboxylic acid, 4,4′-bipy = 4,4′-bipyridine, and py = pyridine) have been hydro(solvo)thermally synthesized by fine control over synthetic conditions, such as solvent and pH value, and structurally characterized. It is shown through single-crystal X-ray diffractions that the ligands H3EIDC can be either singly, doubly, or triply deprotonated and can coordinate to Ni(II), Mn(II) or Cd(II) ions in μ2 or μ3 modes. Compound 1 is a zero-dimensional (0D) symmetrical tetranuclear molecular square. Compound 2 exhibits a two-dimensional (2D) sheet, in which alternate left- and right-handed helical chains are bridged by 4,4′-bipy linkages. Compound 3 assumes a 2D honeycomb-like sheet built up from μ3-EIDC3− and Mn(II) atoms. Compound 4 possesses a novel three-dimensional (3D) structure constructed from 2D ...

Four novel frameworks built by imidazole-based dicarboxylate ligands: hydro(solvo)thermal synthesis, crystal structures, and properties.

Two chiral three-dimensional (3-D) coordination polymers, [Cd4(μ3-HPhIDC)2(μ4-HPhIDC)2(H2O)] (1) and two achiral 3-D coordination polymers, [Mn1.5(μ3-PhIDC)(H2O)3] (2) and [Mn(μ3-HPhIDC)(H2O)]2} (3), have been synthesized by hydro(solvo)thermal reaction, employing 2-phenyl-1H-imidazole-4,5-dicarboxylic acid (H3PhIDC) as organic ligand, and characterized by single-crystal X-ray diffraction, elemental analyses, and IR spectra. Polymer 1 crystallizes in the orthorhombic chiral space group P2(1)2(1)2(1) and exhibits a 3-D framework, in which two-dimensional (2-D) layers are composed of right-handed helices along the b-axis and are further pillared by μ4-HPhIDC2− linkages. Polymer 2 crystallizes in trigonal chiral space group R3 and presents a novel 3-D structure, which is generated from 2-D honeycomb-like layers, containing similar right-handed helical chains along the a or b axes, respectively. Polymer 3 also has a 3-D architecture and is composed of novel 2-D stairlike layers in the bc plane. The theoretic...

One Chiral and Two Achiral 3-D Coordination Polymers Constructed by 2-Phenyl Imidazole Dicarboxylate

Four metal–organic frameworks, namely, [Cd2(μ2-HPhIDC)2(phen)2] (H3PhIDC = 2-phenyl-1H-imidazole-4,5-dicarboxylic acid, phen = 1,10-phenanthroline) (1), [Cd2(μ2-HPhIDC)2(2,2′-bipy)2] (2,2′-bipy = 2,2′-bipyridine) (2), [Pb3(μ4-PhIDC)2(H2O)] (3) and [Sr(μ2-H2PhIDC)2(H2O)4]·2H2O (4) have been synthesized under hydro(solvo)thermal conditions, and characterized by elemental analysis, IR spectroscopy and single crystal X-ray diffraction. Both 1 and 2 are one-dimensional (1-D) infinite chains. Compound 3 features a two-dimensional (2-D) framework, in which Pb2+ ions are bridged by μ4-PhIDC3− ligands. Compound 4 possesses a three-dimensional (3-D) framework with a uninodal 4-connected net. The thermal and photoluminescence properties of polymers 1–4 have been investigated as well.

2-Phenyl-4,5-imidazole dicarboxylate-based metal–organic frameworks assembled under hydro(solvo)thermal conditions

Two new metal–organic frameworks, {[Co3(μ3-DMPhIDC)2(H2O)6]·2H2O}n (1) and {[Mn5(μ3-DMPhIDC)2(μ2-HDMPhIDC)2(Phen)5]·2CH3OH·3H2O}n (2) (H3DMPhIDC = 2-(3,4-dimethylphenyl)-1H-imidazole-4,5-dicarboxyl...

Huijie Lu

Papers

Four novel frameworks built by imidazole-based dicarboxylate ligands: hydro(solvo)thermal synthesis, crystal structures, and properties.

One Chiral and Two Achiral 3-D Coordination Polymers Constructed by 2-Phenyl Imidazole Dicarboxylate

2-Phenyl-4,5-imidazole dicarboxylate-based metal–organic frameworks assembled under hydro(solvo)thermal conditions

Two Unprecedented Transition-Metal–Organic Frameworks Showing One Dimensional-Hexagonal Channel Open Network and Two-Dimensional Sheet Structures