Themed collection MOFs: three decades of pioneering research

A new synthetic approach has led to the incorporation of TCNQ and F₄TCNQ dianions into a wide variety of structures.

Coordination polymers (CPs) and metal–organic frameworks (MOFs) are among the most prolific research areas of crystal engineering in the last 15 years, and the IUPAC Inorganic Chemistry Division has therefore initiated a task group that is currently trying to work out what they really are, or are not. This highlight is a progress report of IUPAC project 2009-012-2-200.

A solvent-free mechanochemical method was successfully developed to synthesize CALF-20, a well-known metal–organic framework for industrial CO₂ capture.

In this work, we show how the combination of soluble non-polar and polar links allows for the preparation of multivariate metal–organic frameworks (MTV MOFs) that exhibit dipolar solid-solution behavior.

We report the selective synthesis of 2D semiconductive coordination polymers with a (–Ag–S–)_n network.

The variable architectures of two new porous coordination polymers, controlled by solvent system, exhibit a structural progression from an unusual non-crystallographic net to a (4,6)-connected framework with fsh topology.

A unique porous Cu(I) metal–organic framework, {[Cu₂(pyzdc)]·0.83H₂O}_n, has been synthesized via in situ reduction of Cu(II) salt by dihydroxyfumaric acid.

TCNQ²⁻ acts as a planar 4-connecting ligand in a series of 3D coordination networks that contain large hexagonal channels.

We report that two isomorphic frameworks based on naphthalenediimide and thiophenedicarboxylate show different charge-transfer interactions with electro-donating aromatic molecules.

We present a method to selectively synthesize crystal polymorphs of [Zn₂(bdc)₂(dabco)]_n (1) and [Zn₂(bdc)₂(bpy)]_n (2), either the pillared 2D square-grid nets (1_sql or 2_sql) or the pillared 2D Kagomé nets (1_kgm or 2_kgm) by simply changing the crystallization temperature.

Three solvent templated novel coordination frameworks with different pore sizes and shapes [Cd(tci) (Me₂NH₂)].DMF ((1), [ Cd₃.(tci)₂ (DEF)₂].DEF ((2), and [ Cd_1.5.(tci)(PrOH)].2PrOH ((3) have been synthesized using a flexible tricarboxylate ligand tris(2-carboxyethyl) isocyanurate (tciH₃) and Cd(NO₃)₂.4H₂O in DMF/DEF/PrOH as solvents.

The family of coordination networks sql-M-aqua (M = Mn, Ni, Co, Zn) each exhibit an S-shaped water sorption isotherm, fast uptake kinetics, and hydrolytic stability over 100 cycles, ideal for atmospheric water harvesting at 0–30% relative humidity.

We report the synthesis of two novel coordination networks, ZRFSIX-21-Cu-α and ZRFSIX-21-Cu-β, utilising hexafluorozirconate (ZrF₆²⁻) anions. Both materials are shown to be C₂H₂ selective over different gases, based on the synthesised phases.

Isoreticulation of MOFs made of pyrazole carboxylate linkers and Mn nodes is nontrivial due to linker flexibility and a variety of accessible Mn nodes. The use of tetratopic hinged linkers to form porous 3D MOFs was identified as a viable strategy.

Using the new bifunctional PyImPr linker and cadmium, two coordination networks, sustained by rod building blocks, form 2D or 3D supramolecular isomers that undergo open-to-closed phase transformations enabled by the flexible linker.

Careful control of synthetic conditions allows isolation of highly porous hcp topology Zr and Hf MOFs containing a linker with a potentially reactive alkyne spacer.

Three new polycatenated mixed-ligand MOFs containing fluorene and naphthalene scaffolds have been solvothermally synthesized. Their solid-state luminescence has been investigated showing a Förster resonance energy transfer involving the two linkers.

Zirconium-based metal organic frameworks (MOFs) are of great significance in supramolecular coordination chemistry, mainly as catalysts, due to their chemical stability and structural diversity.

Cation-modified and robust zirconium-based metal–organic frameworks demonstrate enhanced performance for carbon dioxide capture.

The combination of 4-hydroxbenzoic acid with metal ions Li⁺, Mg²⁺ and Cu²⁺ leads to the formation of novel 2D and 3D networks.

ZIF-7 films with diverse microstructures were in situ fabricated on Co–Al/Mg–Al HTlc-functionalized substrates, demonstrating that metal ions residing in the inorganic buffer layers did not have to be consistent with those in the MOF framework.

The structures and properties of a series of charge transfer complexes involving the radical anionic forms of TCNQ and F₄TCNQ are described.

Controlling the particle size of a flexible metal–organic framework demonstrates that a 2D to 3D transformation gives a kinetically-trapped, structurally-locked form.

The reductive coordination replication of V₂O₅ patterns provides the vanadium(III) species required to build the mesostructures of [V(OH)ndc]_n.

The dianionic form of TCNQF₄ in combination with a wide variety of e⁻-acceptor cations is able to form a series of intensely coloured charge-transfer complexes.

A remarkable single crystal-to-single crystal transformation and an unusual mode of interpenetration are reported as part of an investigation into coordination polymers formed when Cu(II) centres are linked by singly-charged dicarboxylate ligands.

Four novel Cu(I)–Me₂bpm/{C₂H₄, CO} adducts were prepared by the combination of Cu(I) ion with {BF₄⁻, ClO₄⁻or PF₆⁻} anions and 6,6'-dimethyl-4,4'-bipyrimidine (Me₂bpm) as a related bpm ligand under C₂H₄ or CO.

Novel 1-D chain, 1-D ladder, 2-D sheet Cu(I) C₂H₄ adducts and 3-D Cu(I) cage compound, in which a ClO₄⁻, BF₄⁻ or SiF₆²⁻ anion is accommodated in the inside cavity, were self-assembled by the combination of a Cu(I) ion and 4,4′-bipyrimidine.

Dicarboxylate anions derived from natural sugars are useful building blocks in the creation of chiral and achiral coordination polymers.

Polycyanometallate anions clearly demonstrate their availability for constructing porous magnetic frameworks and responding to chemical stimuli as a multifunctional building unit.