Isoreticular two-dimensional magnetic coordination polymers prepared through pre-synthetic ligand functionalization

Electrical conductivity and magnetic bistability in metal–organic frameworks and coordination polymers: charge transport and spin crossover at the nanoscale

This review aims to reassess the progress, issues and opportunities in the path towards integrating conductive and magnetically bistable coordination polymers and metal–organic frameworks as active components in electronic devices.

2D magnetic MOFs with micron-lateral size by liquid exfoliation

Herein, we obtained high-quality nanosheets for a whole family of Fe-based magnetic MOFs, MUV-1-X, through a liquid exfoliation procedure.

Field-induced slow magnetic relaxation in two interpenetrated cobalt(ii) metal–organic framework isomers

Two interpenetrated cobalt(ii) metal–organic framework (MOF) isomers were successfully synthesized and magnetically characterized. These compounds are the first example of MOF isomers showing field-induced single-ion magnet behavior.

Two-dimensional polymers with versatile functionalities via gemini monomers

Two-dimensional synthetic polymers (2DSPs) are sheet-like macromolecules consisting of covalently linked repeat units in two directions. Access to 2DSPs with controlled size and shape and diverse functionality has been limited because of the need for monomers to retain their crystallinity throughout polymerization. Here, we describe a synthetic strategy for 2DSPs that obviates the need for crystallinity, via the free radical copolymerization of amphiphilic gemini monomers and their monomeric derivatives arranged in a bilayer at solid-liquid interfaces. The ease of this strategy allowed the preparation of 2DSPs with well-controlled size and shape and diverse functionality on solid templates composed of various materials with wide-ranging surface curvatures and dimensions. The resulting 2DSPs showed remarkable mechanical strength and have multiple applications, such as nanolithographic resist and antibacterial agent. The broad scope of this approach markedly expands the chemistry, morphology, and functionality of 2DSPs accessible for practical applications.

Dysprosium Chlorocyanoanilate-Based 2D-Layered Coordination Polymers

A series of two-dimensional (2D)-layered coordination polymers (CPs) based on the heterosubstituted anilate ligand ClCNAn^2- derived from 3-chloro-6-cyano-2,5-dihydroxybenzoquinone and Dy^III are reported. By changes in the synthetic methods (layering technique, solvothermal or conventional one-pot reactions) and conditions (solvent, concentration, etc.), different types of 2D extended networks could be prepared and structurally characterized. Compounds 1 and 1', two polymorphs with the formula [Dy₂(ClCNAn)₃(DMSO)₆]_n·(H₂O)_x [x = 7 (1), 0 (1')], were prepared by a conventional one-pot reaction and recrystallized at different concentrations. Compound 2, formulated as [Dy₂(ClCNAn)₃(DMF)₆]_n, was prepared by a layering technique, while compound 3, formulated as {(Me₂NH₂)₂[Dy₂(ClCNAn)₄(H₂O)₂]·(DMF)₂·(H₂O)₅}_n, was obtained by a solvothermal method. Compounds 1 and 2 are neutral 2D CPs of the ClCNAn^2- ligand and Dy^III ions, while 3 presents 2D anionic layers of [Dy₂(ClCNAn)₄(H₂O)₂]^2- alternating with cationic layers of Me₂NH₂⁺ ions. These compounds show very diverse networks, with compound 1 forming 2D (8,3) and (4,3) topology with eight- and four-membered rings with square cavities, 1' and 2, respectively, a 2D (6,3) topology with six-membered rings (a rectangular cavity for 1' and a regular hexagonal cavity for 2), and 3 a 2D (4,4) topology with distorted square cavities. In this respect, 1 and 1' represent the first examples of polymorphism in the family of anilate-based CPs. Thermal analysis measurements (differential scanning calorimetry and thermogravimetry) show an exothermic polymorphic transformation from the kinetically stable 1' phase to the thermodynamically stable phase 1. The magnetic behavior of 1-3 very likely indicates depopulation of the m_J levels, while the presence of weak antiferromagnetic coupling between the Dy^III centers mediated by the anilate bridge cannot be excluded.

Superhydrophobic states of 2D nanomaterials controlled by atomic defects can modulate cell adhesion

We introduced a new concept to the control of wetting characteristics by modulating the degree of atomic defects of two-dimensional transition metal dichalcogenide nanoassemblies of molybdenum disulfide. This work shed new light on the role of atomic vacancies on wetting characteristic that can be leveraged to develop a new class of superhydrophobic surfaces for various applications without altering their topography.

A semiconducting layered metal-organic framework magnet

The realization of ferromagnetism in semiconductors is an attractive avenue for the development of spintronic applications. Here, we report a semiconducting layered metal-organic framework (MOF), namely K₃Fe₂[(2,3,9,10,16,17,23,24-octahydroxy phthalocyaninato)Fe] (K₃Fe₂[PcFe-O₈]) with spontaneous magnetization. This layered MOF features in-plane full π-d conjugation and exhibits semiconducting behavior with a room temperature carrier mobility of 15 ± 2 cm² V⁻¹ s⁻¹ as determined by time-resolved Terahertz spectroscopy. Magnetization experiments and ⁵⁷Fe Mössbauer spectroscopy demonstrate the presence of long-range magnetic correlations in K₃Fe₂[PcFe-O₈] arising from the magnetic coupling between iron centers via delocalized π electrons. The sample exhibits superparamagnetic features due to a distribution of crystal size and possesses magnetic hysteresis up to 350 K. Our work sets the stage for the development of spintronic materials exploiting magnetic MOF semiconductors.

Semiconductors that display spontaneous magnetization are attractive for spintronic applications. Here the authors report a p-type semiconducting layered metal–organic framework that displays a room temperature carrier mobility of 15 ± 2 cm² V⁻¹ s⁻¹ as well as long-range magnetic correlations.

Structural Engineering of Low-Dimensional Metal-Organic Frameworks: Synthesis, Properties, and Applications

Low-dimensional metal-organic frameworks (LD MOFs) have attracted increasing attention in recent years, which successfully combine the unique properties of MOFs, e.g., large surface area, tailorable structure, and uniform cavity, with the distinctive physical and chemical properties of LD nanomaterials, e.g., high aspect ratio, abundant accessible active sites, and flexibility. Significant progress has been made in the morphological and structural regulation of LD MOFs in recent years. It is still of great significance to further explore the synthetic principles and dimensional-dependent properties of LD MOFs. In this review, recent progress in the synthesis of LD MOF-based materials and their applications are summarized, with an emphasis on the distinctive advantages of LD MOFs over their bulk counterparties. First, the unique physical and chemical properties of LD MOF-based materials are briefly introduced. Synthetic strategies of various LD MOFs, including 1D MOFs, 2D MOFs, and LD MOF-based composites, as well as their derivatives, are then summarized. Furthermore, the potential applications of LD MOF-based materials in catalysis, energy storage, gas adsorption and separation, and sensing are introduced. Finally, challenges and opportunities of this fascinating research field are proposed.

From mononuclear to two-dimensional cobalt(ii) complexes based on a mixed benzimidazole–dicarboxylate strategy: syntheses, structures, and magnetic properties

Three cobalt(ii) complexes with diverse structure dimensions based on a mixed benzimidazole–dicarboxylate strategy have been synthesized hydrothermally and characterized structurally and magnetically.

Two-dimensional magnetic materials of cobalt(ii) triangular lattices constructed by a mixed benzimidazole–dicarboxylate strategy

Herein, three two-dimensional magnetic materials of cobalt(ii) coordination polymers with triangular lattices were synthesized using a mixed benzimidazole–dicarboxylate strategy.

Polymorphic layered copper phosphonates: exfoliation and proton conductivity studies

α-Cu(4-cnappH)(H₂O) (α-Cu-1), α-Cu(4-cnappH)(H₂O)·0.5H₂O (α-Cu-2) and β-Cu(4-cnappH)(H₂O) (β-Cu) [4-cnappH₃ = (4-carboxynaphthalen-1-yl)phosphonic acid] are polymorphic layered compounds. Proton conduction is more favorable in α-Cu-2 than in α-Cu-1, but exfoliation into nanosheets decreases the conductivity.