A Semiconducting Lamella Polymer

Layered Organic Metal Chalcogenides (OMCs): From Bulk to Two-Dimensional Materials

The modification of inorganic two-dimensional (2D) materials with organic functional motifs is in high demand for the optimization of their properties, but it is still a daunting challenge. Organic metal chalcogenides (OMCs) are a type of newly emerging 2D materials, with metal chalcogenide layers covalently anchored by long-range ordered organic functional motifs, these materials are extremely desirable but impossible to realize by traditional methods. Both the inorganic layer and organic functional motifs of OMCs are highly designable and thus provide this type of 2D materials with enormous variety in terms of their structure and properties. This Minireview aims to review the latest developments in OMCs and their bulk precursors. Firstly, the structure types of the bulk precursors for OMCs are introduced. Second, the synthesis and applications of OMC 2D materials in photoelectricity, catalysis, sensors, and energy transfer are explored. Finally, the challenges and perspectives for future research on OMCs are discussed.

Epitaxial coordination assembly of a semi-conductive silver-chalcogenide layer-based MOF

Using a carboxylic acid linker, this work achieved the epitaxially coordinated assembly of a Ag-S layer into a three-dimensional semi-conductive framework, with high thermal stability, as well as an interesting temperature-dependent luminescence response. This work provides a new avenue to prepare semi-conductive metal-chalcogenide layer-based materials in electricity-related applications.

N,N′-Diarylformamidine Dithiocarbamate Ag(I) Cluster and Coordination Polymer

An Ag(I)formamidine cluster Ag6L16 (1) and an Ag(I)formamidine coordination polymer Ag7(L2)2 2 (L1 = N,N′-bis(2,6-disopropylphenyl) formamidine dithiocarbamate and L2 = N,N′-mesityl formamidine dithiocarbamate) have been synthesized from the reactions of L1 and L2 with AgNO3 respectively. The complexes were characterized using spectroscopic and analytical methods, including single-crystal X-ray diffraction. In the structure of 1, a six vertex distorted square bi-pyramidal octahedron is formed from an Ag6 core. The N,N′-bis(2,6-disopropylphenyl) formamidine dithiocarbamate ligands stabilize this core through two main –CS2 bridging modes giving a propeller like structure. In the structure of 2, each of the two Ag(I) centers are bridged by two N,N′-mesityl formamidine dithiocarbamate ligands forming 8-member Ag2(CS2)2 metallacycles with an inversion center in the middle of the Ag—Ag argentophilic bond. The metallacycles are connected through Ag—S bonds forming ribbons in the crystallographic a-axis. The Ag(I) centers are coordinated to two N,N′-mesitylformamidine dithiocarbamates through the dithiocarbamate S atoms. The thermal decomposition of complexes 1 and 2 had similar thermograms with one major weight loss activity and the formation of elemental silver particles thereafter.

A Chiral 3D Silver(I)-Benzenedithiolate Coordination Polymer exhibiting Photoemission and Non Linear Optical Response

A new tridimentional Metal Organic Chalcogenolate, made of 1,3-benzenedithiolate bridging ligand and Ag(I), [Ag2(1,3-BDT)]n, is reported. This coordination polymer has good thermal stability in air and while it is insulator,...

Size and Quality Enhancement of 2D Semiconducting Metal-Organic Chalcogenolates by Amine Addition

The use of two-dimensional (2D) materials in next-generation technologies is often limited by small lateral size and/or crystal defects. Here, we introduce a simple chemical strategy to improve the size and overall quality of 2D metal-organic chalcogenolates (MOCs), a new class of hybrid organic-inorganic 2D semiconductors that can exhibit in-plane anisotropy and blue luminescence. By inducing the formation of silver-amine complexes during a solution growth method, we increase the average size of silver phenylselenolate (AgSePh) microcrystals from <5 μm to >1 mm, while simultaneously extending the photoluminescence lifetime and suppressing mid-gap emission. Mechanistic studies using ⁷⁷Se NMR suggest dual roles for the amine in promoting the formation of a key reactive intermediate and slowing down the final conversion to AgSePh. Finally, we show that amine addition is generalizable to the synthesis of other 2D MOCs, as demonstrated by the growth of single crystals of silver 4-methylphenylselenolate (AgSePhMe), a novel member of the 2D MOC family.

Dithiol-Dithione Tautomerism of 2,3-Pyrazinedithiol in the Synthesis of Copper and Silver Coordination Compounds

A promising strategy for new electrically conductive coordination polymers is the combination of d¹⁰ metal ions, which tolerate short metal···metal distances, with dithiolene linkers, known for their "non-innocent" redox behavior. This study explores the coordination chemistry of 2,3-pyrazinedithiol (H₂pdt) toward Cu⁺ and Ag⁺ ions, highlighting similarities and differences. The synthetic approach, starting with the fully protonated ligand, allowed the isolation of a homoleptic bis(dithiolene) complex with formal Cu^I atoms, [Cu(H₂pdt)₂]Cl (1). This complex was further transformed to a 1D coordination polymer with short metal···metal distances, ^1D[Cu(Hpdt)] (2^Cu). The larger Ag⁺ ion directly built up a very similar coordination polymer, ^1D[Ag(Hpdt)] (2^Ag), without any appearance of an intermediate metal complex. The coordination polymer ^1D[Cu(H₂pdt)I] (4), like complex 1, bears fully protonated H₂pdt ligands in their dithione form. Upon heating, both compounds underwent auto-oxidation coupled with a dehydrogenation of the ligand to form the open-shell neutral copper(II) complex [Cu(Hpdt)₂] (3) and the coordination polymer ^1D[Cu₂I₂(H₂pdt)(Hpdt)] (5), respectively. For all presented compounds, crystal structures are discussed in-depth. Furthermore, properties of 1, 3, and those of the three 1D coordination polymers, 2^Ag, 2^Cu, and 4, were investigated by UV-vis-NIR spectroscopy, cyclic voltammetry, and variable-temperature magnetic susceptibility, and direct current (dc)-conductivity measurements. The experimental results are compared and discussed with the aid of DFT simulations.

Metal-Organosulfide Coordination Polymer Nanosheet Array as a Battery-Type Electrode for an Asymmetric Supercapacitor

Metal-organosulfide coordination polymers (MOSCPs) are important functional materials with attractive application prospects. Herein a two-dimensional structural MOSCP was fabricated on nickel foam with nanosheet array morphology. When as the binder-free battery-type electrode for a supercapacitor, the as-prepared Co-based MOSCP showed high specific capacitance (759 F g^-1/379.5 C g^-1/105.4 mAh g^-1 at 0.5 A g^-1), excellent rate performance (58.8% after the current density increased 20 times), and good cycle stability (73.4% after 5000 cycles). In addition, a maximum energy density of 31.97 Wh kg^-1 was obtained at a power density of 375.01 W kg^-1 in the assembled asymmetric supercapacitor device. These results indicated that this work would open up a new path to design and prepare the battery-type electrode for a supercapacitor by exploring nanoscale MOSCP materials.

A hydrophobic semiconducting metal–organic framework assembled from silver chalcogenide wires

Silver chalcogenide wires are for the first time assembled into a rigid framework structure using a fluorinated carboxylate ligand, where electron transfer along Ag–S chains enables semi-conduction.

New Lamellar Silver Thiolate Coordination Polymers with Tunable Photoluminescence Energies by Metal Substitution

The structures of two lamellar silver thiolate coordination polymers [Ag( p-SPhCO₂H)] _n (1) and [Ag( p-SPhCO₂Me)] _n (2) are described for the first time. Their inorganic part is composed of distorted Ag₃S₃ honeycomb networks separated by noninterpenetrated thiolate ligands. The main difference between the two compounds arises from dimeric hydrogen bonds present for the carboxylic acids. Indepth photophysical studies show that the silver thiolates exhibit multiemission properties, implying luminescence thermochromism. More interestingly, the synthesis of a heterometallic lamellar compound, [Ag_0.85Cu_0.15( p-SPhCO₂H)] _n (3), allows to obtain mixed metal thiolate coordination polymers and to tune the photophysical properties with the excitation wavelengths from a green vibronic luminescence to a single red emission band.

The use of a semi-flexible bipyrimidyl ligand for the construction of azide-based coordination polymers: structural diversities and magnetic properties

Using a semi-flexible quadritopic N-donor ligand, 5,5'-bipyrimidine (bpym), four new azide-based coordination polymers, {[Co2(bpym)(N3)4]·MeCN}n (1), [Co(bpym)(N3)2]n (2), [Mn(bpym)(N3)2]n (3) and {[Ni3(bpym)3(N3)6]·2H2O}n (4) were synthesized and structurally characterized. With bpym aciting as a planar μ4-bridging ligand, the resulting compound, 1, comprised a net-to-net 3D framework composed of two grid-like 44-subnets, Co(EE-N3)2-based and Co2(bpym)-based sheets, with a (4,6)-connected (42·64)(48·66·8)2 topology. Compound 2 adopted a 3D pillared-layer framework with a pts topology based on six-connected Co(ii) centers and four-connected twisted μ4-bpym ligands, while compound 3 adopted a 3D pillared-layer structure with a bcu topology based on Co(EE-N3)2-based 44-layers and two-connected twisted μ2-bpym pillars. In contrast, compound 4 had a 2D layered structure composed of 1D Ni(ii) chains with alternating double EE-N3 and double EO-N3 bridges in an EE-EE-EO sequence and two-connected bpym linkers. The magnetic properties of 1-4 were investigated. The findings indicate that 1 showed weak ferromagnetism due to spin-canted antiferromagnetism and long-range magnetic ordering with a critical temperature, TC = 12.6 K. In contrast, compound 2 exhibited weak ferromagnetism due to spin-canted antiferromagnetism and antiferromagnetic ordering. In compound 3, antiferromagnetic interactions dominated between the Mn(ii) centers through the EE-N3 bridges. In compound 4, the antiferromagnetic and ferromagnetic interactions were transmitted through double EE-N3 and double EO-N3 bridges, respectively, resulting in an AF-AF-F topological ferrimagnetic Ni(ii) chain. Furthermore, field-induced magnetic phase transitions of metamagnetism for 2 and 4 were also observed below TN = 3.6 K and 8.2 K, respectively.

End-Capping π-Conjugated Systems with Medium-Sized Sulfur-Containing Rings: A Route Towards Solution-Processable Air-Stable Semiconductors

The sulfur-containing nine-membered heterocycle thiacyclononene (TN) was evaluated as a new type of end-capping group for π-conjugated systems. A systematic study on TN-capped α-oligothiophenes (TNnTs; n=4-7) revealed that the capping with TN, which adopts a bent conformation, imparts the resulting oligothiophenes with drastically increased solubility at approximately 140 °C and high electrochemical stability, whereas the electronic structure remains virtually unperturbed. The even-numbered oligothiophenes TN4T and TN6T form characteristic offset herringbone-type packing structures on account of the steric repulsion between the TN rings and the presence of intermolecular nonbonding S⋅⋅⋅S interactions. This packing mode in combination with the high solubility enabled the solution-process fabrication of field-effect transistors based on TN6T, which exhibited a high performance without degradation even upon exposure to air.

Structure and electrical properties of a one-dimensional polymeric silver thiosaccharinate complex with argentophilic interactions

Among the potential applications of coordination polymers, electrical conductivity ranks high in technological interest. We report the synthesis, crystal structure and spectroscopic analysis of an Ag^I-thiosaccharinate one-dimensional coordination polymer {systematic name: catena-poly[[[aquatetrakis(μ₃-1,1-dioxo-1,2-benzisothiazole-3-thiolato-κ³N:S³:S³)tetrasilver(I)]-μ₂-4,4'-(propane-1,3-diyl)dipyridine-κ²N:N'] dimethyl sulfoxide hemisolvate]}, {[Ag₄(C₇H₄NO₂S₂)₄(C₁₃H₁₄N₂)(H₂O)]·0.5C₂H₆OS}_n, with the 4,4'-(propane-1,3-diyl)dipyridine ligand acting as a spacer. A relevant feature of the structure is the presence of an unusually short Ag...Ag distance of 2.8306 (9) Å, well within the range of argentophilic interactions, confirmed experimentally as such by a Raman study on the low-frequency spectrum, and corroborated theoretically by an Atoms in Molecules (AIM) analysis of the calculated electron density. Electrical conductivity measurements show that this complex can act as a semiconductor with moderate conductivity.

Set of Multifunctional Azo Functionalized Semiconducting Cd(II)-MOFs Showing Photoswitching Property and Selective CO2 Adsorption

Syntheses, structural characterizations, photoluminescence, and adsorption properties of three new azo-functionalized Cd(II)-MOFs, namely, {[Cd(azbpy)(msuc)]·2.5(H₂O)}_n (2), {[Cd(azbpy)(mglu)]·5(H₂O)}_n (3), and {[Cd_1.5(azbpy)₂(glu)]·(NO₃)·MeOH}_n (4) [where msuc^2- = methylsuccinate; mglut^2- = methylglutarate; glut^2- = glutarate; azbpy = 4,4'-azobispyridine] have been reported. The compounds show different structures only with the variation of aliphatic dicarboxylates. The photoswitching behavior for the above-mentioned newly synthesized Cd(II)-MOFs along with one of our previously reported other azo-functionalized Cd(II)-MOF, namely, {[Cd(azbpy)(suc)]·2(H₂O)}_n (1), has been studied extensively. At photoilluminated condition, the conductivity values can draw a clear structure-property relationship among the structures of compounds 1-4. Single crystal structural analysis reveals that all the compounds exhibit a three-dimensional (3D) framework connected by azbpy linker and respective aliphatic dicarboxylate through their bis-chelating mono/bis oxo-bridging fashion. Compounds 1-3 exhibit an iso-structural honeycomb like 3D framework showing the same coordination environments, where the metal-carboxylate 2D sheets of compounds 1-3 are pillared by N,N'-donor azbpy linkers. On the other hand, compound 4 exhibits a 2-fold interpenetrated 3D framework with a little difference in its coordination environment and the pillaring of 1D metal-carboxylate ladder by azbpy linkers. All the compounds significantly demonstrate their enhanced sensitivity under light rather than the dark condition. The gas and solvent vapor sorption studies have been performed for the synthesized compounds 2-4. Moreover, compound 2 exhibits an enhanced type IV selective CO₂ adsorption isotherm over N₂ along with the appearance of gate opening phenomena in that.

Structure, solution assembly, and electroconductivity of nanosized argento-organic-cluster/framework templated by chromate

In view of elucidating potential structures and assembly mechanism of silver clusters and silver cluster-based metal-organic frameworks, we prepared four argento-organic-clusters/frameworks where the structures were directed by chromate in the presence of different thiolates. All four structures with ^tBuC₆H₄S^-, SⁱBu^-, and SⁱPr^- consist of three core-shells, an inner CrO₄^2-, an intermediate Ag-S aggregate and finally the protective organic moieties. {(HNEt₃)₃[Ag(CrO₄)₄@Ag₄₆(SC₆H₄^tBu)₂₄(CF₃COO)₁₈(DMF)₄]} (1) is a supertetrahedron with an inner Ag(CrO₄)₄ tetrahedron shelled by four fused Ag_11.5S₆ lobes. [(CrO₄)₅@Ag₄₀(SⁱBu)₂₇(CF₃COO)₃]_n (2) is an undulated snake-like tube housing the infinite CrO₄^2- tetrahedra. [(CrO₄)₂@Ag₄₁(SⁱBu)₃₀(NO₃)₃(CN)₄]_n (3) forms an uncommon 7-connected kwh network incorporating hexagonal layers of Ag₁₉(SⁱBu)₁₅ balls with a single inner CrO₄^2- connected by another Ag atom. Both enantiomeric chiral qtz frameworks of [CrO₄@Ag₂₀(SⁱPr)₁₀(Cr₂O₇)₂(COOCF₃)₄(DMF)₄]_n (4) were structurally characterized. In 4, Cr₂O₇^2- connects the Ag₂₀(SⁱPr)₁₀ clusters with a trapped CrO₄^2- into a 3D quartz (qtz) structure, where the spherical cluster acts like oxygen and Cr₂O₇^2- takes the place of Si in SiO₂. Electrospray ionization mass spectrometry (ESI-MS) analysis of the reaction solutions of 1-4 clearly indicated that (i) the Ag(CrO₄)₄@Ag₄₆ core of 1 can retain its molecular structure in the solution and (ii) the chromate-templated polynuclear silver-thiolate species in solution are important building blocks to construct the 1D or 3D motif for 2-4. The electrochemistry in sulfuric acid and enhancement of the electrical conductivity upon I₂ doping have also been reported.

In-Situ Ligand Formation-Driven Preparation of a Heterometallic Metal-Organic Framework for Highly Selective Separation of Light Hydrocarbons and Efficient Mercury Adsorption

By means of the in situ ligand formation strategy and hard-soft acid-base (HSAB) theory, two types of independent In(COO)4 and Cu6S6 clusters were rationally embedded into the heterometallic metal-organic framework (HMOF) {[(CH3)2NH2]InCu4L4·xS}n (BUT-52). BUT-52 exhibits a three-dimensional (3D) anionic framework structure and has sulfur decorating the dumbbell-shaped cages with the external edges of 24 and 14 Å by the internal edges. Remarkably, because of the stronger charge-induced interactions between the charged MOF skeleton and the easily polarized C2 hydrocarbons (C2s), BUT-52 was used for C2s over CH4 and shows both high adsorption heats of C2s and selective separation abilities for C2s/CH4. Furthermore, BUT-52 also displays efficient mercury adsorption resulting from the stronger-binding ability beween the sulfur and the mercury and can remove 92% mercury from methanol solution even with the initial concentration as low as 100 mg/L. The results in this work indicate the feasibility of BUT-52 for the separation of light hydrocarbons and efficient adsorption/removal of mercury.

Azide-bridged Cu(ii), Mn(ii) and Co(ii) coordination polymers constructed with a bifunctional ligand of 6-(1H-tetrazol-5-yl)-2,2′-bipyridine

Three new azide-bridged coordination polymers, [M(N₃)(tzbp)]_n (M = Cu, 1·Cu; Mn, 2·Mn; Co, 3·Co), were successfully prepared by introducing a bifunctional tetrazolate/2,2′-bipyridine ligand, 6-(1H-tetrazol-5-yl)-2,2′-bipyridine (Htzbp).

Four new silver phosphonates constructed from semi-rigid phosphonate ligands: synthesis, structure and properties

Four new silver phosphonates with interesting structures and luminescent properties have been hydrothermally synthesized and systematically characterized.

Hemilabile silver(i) complexes containing pyridyl chalcogenolate (S, Se) ligands and their utility as molecular precursors for silver chalcogenides

A series of silver triphenylphosphine complexes containing pyridyl chacogenolate (S, Se) ligands has been synthesized by employing [AgCl(PPh₃)₃] and [Ag₂(μ-Cl)₂(PPh₃)₄].

One-dimensional lanthanide coordination polymers: synthesis, structures, and single-ion magnetic behaviour

The one-dimensional Dy coordination polymer displays a single-ion magnetic behaviour with a narrow distribution of relaxation under a dc field.

Computational screening of structural and compositional factors for electrically conductive coordination polymers

We test a range of building blocks and connectivity for the construction of electroactive metal–organic frameworks.

An electroactive porous network from covalent metal–dithiolene links

Direct reaction between a hexathiol and PtCl₂ leads to the formation of a covalent metal–organic framework (CMOF) featuring substantial porosity, redox activity and ion exchange capability.

Metal-organic frameworks as a tunable platform for designing functional molecular materials

Metal-organic frameworks (MOFs), also known as coordination polymers, represent an interesting class of crystalline molecular materials that are synthesized by combining metal-connecting points and bridging ligands. The modular nature of and mild conditions for MOF synthesis have permitted the rational structural design of numerous MOFs and the incorporation of various functionalities via constituent building blocks. The resulting designer MOFs have shown promise for applications in a number of areas, including gas storage/separation, nonlinear optics/ferroelectricity, catalysis, energy conversion/storage, chemical sensing, biomedical imaging, and drug delivery. The structure-property relationships of MOFs can also be readily established by taking advantage of the knowledge of their detailed atomic structures, which enables fine-tuning of their functionalities for desired applications. Through the combination of molecular synthesis and crystal engineering, MOFs thus present an unprecedented opportunity for the rational and precise design of functional materials.