Hetero-interpenetrated metal-organic frameworks

Interpenetrated metal-organic frameworks (MOFs) comprise two or more lattices that are mutually entangled. Interpenetration can be used to tune the structures and pore architectures of MOFs to influence, for example, their stability or interactions with guest molecules. The interpenetrating sublattices are typically identical, but hetero-interpenetrated MOFs, which consist of sublattices that are different from one another, have also been serendipitously produced. Here we describe a strategy for the deliberate synthesis of hetero-interpenetrated MOFs. We use the cubic α-MUF-9 framework as a host sublattice to template the growth of a second sublattice within its pores. Three different secondary sublattices are grown-two of which are not known as standalone MOFs-leading to three different hetero-interpenetrated MOFs. This strategy may serve to combine different properties into one material. We produce an asymmetric catalysis by allocating separate roles to the interpenetrating sublattices in a hetero-interpenetrated MOF: an achiral secondary amine on one sublattice provides the catalytic activity, while the chiral α-MUF-10 host imparts asymmetry to aldol and Henry reactions.

Hetero-interpenetrating porous coordination polymers

Interpenetrating porous coordination polymers (IPCPs) consist of two or more networks that are mechanically interlocked to form a coherent structure. The framework topology and the chemical composition are the two important criteria of interpenetrating networks to distinguish homo-IPCPs from hetero-IPCPs. Compared to rich homo-IPCPs, hetero-IPCPs remain rare and are formed rather unexpectedly. This Frontier article highlights hetero-IPCPs in accordance with the difference and/or identity of individual networks in terms of the framework topology and the chemical composition.

Discovery of hypothetical hetero-interpenetrated MOFs with arbitrarily dissimilar topologies and unit cell shapes

Interpenetration is a commonly observed phenomenon in metal organic frameworks (MOFs) where multiple frameworks are entangled with each other. Using a novel algorithm described here, 18 hypothetical hetero-interpenetrated MOFs were discovered.

A pair of 3D enantiotopic zinc(ii) complexes based on two asymmetric achiral ligands

Two 3D enantiotopic chiral metal–organic frameworks, with ferroelectric behaviors and second-order nonlinear optical effects, were constructed based on achiral ligands in one pot with high enantiomeric excess owing to the hydrogen bonds.

Four coordination polymers derived from a one-pot reaction and their controlled synthesis

Four different Co(ii) coordination polymers have been built by two flexible ligands 4,4'-dicarboxydiphenyl sulfone (4,4'-sdb) and 1,4-bis((1H-imidazol-1-yl)methyl) benzene (BMB) in a one-pot solvothermal reaction. The structures of and are new, and and have been reported. The crystal structures of were obtained, namely [Co(4,4'-sdb)(BMB)]n (), {[Co2(4,4'-sdb)2(BMB)]·2H2O}n (), and [Co3(4,4'-sdb)2(DMF)(H2O)3]n (), but was confirmed by PXRD. Both and are 2D layered structures with sql topology and their point symbol is {4(4)·6(2)}. These complexes have been characterized by single crystal X-ray diffraction, infrared spectroscopy, thermogravimetry, elemental analysis, and powder X-ray diffraction measurements. By changing the synthesis conditions, four different Co(ii) coordination polymers can be obtained respectively.

Tuning different kinds of entangled metal–organic frameworks by modifying the spacer group of aliphatic dicarboxylate ligands and the reactant ratio

Presented here are a series of coordination polymers with different entangled motifs which were synthesized using different dicarboxylic acid ligands and reactant ratios.

Biphenyl-2,4,6,3',5'-pentacarboxylic acid as a tecton for six new Co(II) coordination polymers: pH and N-donor ligand-dependent assemblies, structure diversities and magnetic properties

Six new Co(ii)-based mixed-ligand coordination polymers, namely, [Co2(H3bppc)2(2,2'-bpy)4]·H2O (), [Co2(Hbppc)(2,2'-bpy)2(H2O)]·H2O (), [Co(H2bppc)(H-bpp)]·2H2O (), [Co3(μ3-OH)(bppc)(dps)(CH3CH2OH)]·4H2O (), [Co2(bppc)(bib)(H2O)4]·(H2-bib)0.5·(H2O)3 (), and [Co2(Hbppc)(bix)2]·2H2O (), (H5bppc = biphenyl-2,4,6,3',5'-pentacarboxylic acid, 2,2'-bpy = 2,2'-bipyridine, bpp = 1,3-bis(4-pyridyl)propane, dps = 4,4'-sulfanediyldipyridine, bib = 1,4-bis(imidazol-1-yl)benzene, bix = 1,4-bis(imidazol-1-ylmethyl)benzene), have been obtained under solvothermal conditions. exhibits a 3D supramolecular framework based on a [Co2(H3bppc)2(2,2'-bpy)4] unit. has a (3,4)-connected dmc net with a (4·8(2))(4·8(5)) topology containing alternate binuclear metal clusters and single metal centres. shows a 3D supramolecular architecture constructed from ladder-like arrays decorated with H-bpp. exhibits a binodal (5,7)-connected 3D network based on trinuclear [Co3(μ3-OH)](5+) units with an unusual (3·4(6)·5(2)·6)(3(2)·4(6)·5(7)·6(5)·7) topology. features a (4,6)-connected 3D fsc open framework with binuclear [Co2(H2O)(COO)](3+) units as nodes, and H2-bib and water molecules located in the voids of its framework by hydrogen bonds. possesses a 3D net containing unusual 2D polyrotaxane sheets. Topological analysis reveals that has a (3,4,4)-connected 3D network with a (4·6·7(4))(4·6·7)(6·7(2)·10(2)·11) topology. The structural difference of and is due to the different pH values of the reaction system. Though complexes were synthesised under similar reaction conditions, the carboxylic groups of H5bppc were partially deprotonated in , and and fully deprotonated in and . Complexes display diverse structures depending on different N-donor ligands and the coordination modes of the multicarboxylate ligand. Variable-temperature magnetic susceptibility measurements reveal that complexes show antiferromagnetic interactions.

Facile redox state manipulation in Cu(i) frameworks by utilisation of the redox-active tris(4-(pyridin-4-yl)phenyl)amine ligand

Two Cu(i) frameworks were synthesised with the NPy₃ ligand and Cu(ii) salts to yield electroactive Cu(i) frameworks whose spectral properties varied as a function of the redox state.

A novel [4 + 3] interpenetrated net containing 7-fold interlocking pseudo-helical chains and exceptional catenane-like motifs

The first example of a [4 + 3] 7-fold interpenetrating network was prepared, showing 7-fold interlocking pseudo-helical chains and a unique catenane-like motif with Hopf links.

2D-cadmium MOF and gismondine-like zinc coordination network based on the N-(2-tetrazolethyl)-4′-glycine linker

We have designed and synthesized two new metal-organic-frameworks (MOFs) using the novel N-(2-tetrazolethyl)-4′-glycine spacer (TeGly)²⁻. These materials exhibit intense photoluminescence.

Syntheses, structures, and properties of six cobalt(ii) complexes based on a tripodal tris(4-(1H-1,2,4-triazol-1-yl)phenyl)amine ligand

Six new cobalt(ii) metal–organic frameworks based on the tripodal tris(4-(1H-1,2,4-triazol-1-yl)phenyl)amine (TTPA) ligand with different aromatic carboxylate auxiliary ligands have been synthesized and structurally characterized in detail. All the complexes show optical semiconductive properties.

Two unprecedented entangled coordination polymers based on α-{SiW12O40}4−

Two novel entangled POM-based coordination polymers have been successfully hydrothermally synthesized. Compound 1 presents an unprecedented 2D + 2D → 3D polypseudorotaxane motif, while compound 2 exhibits a self-catenated framework with multi-form helical chains. Photocatalytic experiments reveal that both compounds 1 and 2 can inhibit the photodegradation of Methylene Blue (MB).