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The document is a contents list for the journal CrystEngComm, which focuses on the design and understanding of solid-state and crystalline materials. The issue includes various articles and papers on topics such as organic charge transfer complexes, metal organic frameworks, mechanical properties of cocrystals, and scintillation crystals. The journal is published by The Royal Society of Chemistry, a leading chemistry community that reinvests its profits back into the chemistry community. [Extracted from the article]

The Pb–S‐based coordination polymer (CP), named KGF‐9, [Pb(tadt)]n (tadt = 1,3,4‐thiadiazole‐2,5‐dithiolate), can selectively convert CO2 into HCOO− (>99%) under visible light, with an apparent quantum yield (AQY) of 2.6% at 400 nm, without a cocatalyst. However, KGF‐9 is an intrinsically nonporous CP, and its small specific surface area (<1 m2 g−1) might hinder the realization of its full potential as a photocatalyst. Herein, facile synthetic routes at room temperature are reported through a solid‐state reaction and a liquid‐phase reaction (LPR) using lead(II) acetate as a precursor. The use of lead(II) acetate promotes the deprotonation of the H2tadt ligand, resulting in a faster coordination reaction, a reduced feature size, and a drastic increase in specific surface area (≈10 m2 g−1). A higher AQY for formate production (5.9% at 400 nm) is found for KGF‐9 prepared via a 60 min LPR. The improved photocatalytic activity of the LPR sample is attributed to the presence of long‐lived charge carriers, which is revealed by time‐resolved microwave conductivity measurements. The results of this study provide a simple but effective strategy toward increasing the activity of CP‐based photocatalysts. [ABSTRACT FROM AUTHOR]

Chiral coordination polymers constructed from mandelic acid have shown promise in enantioselective recognition and sensing, whereas its methoxy-protected derivative, α-methoxyphenyl acetic acid, is rarely used as a ligand in coordination polymers. In this study, mandelic acid, 3,5-difluoromandelic acid, and α-methoxyphenyl acetic acid were combined with divalent transition metals and bridging dipyridyl co-ligands to obtain a series of six 1D coordination polymers. The coordination polymers of mandelate and 3,5-difluoromandelate possessed densely packed structures stabilised by hydrogen bonding. In contrast, the use of (R)-α-methoxyphenyl acetic acid gave rise to zig-zag chains with significant solvent-accessible void space. (R)-Mandelic acid and its derivatives are useful ligands for the synthesis of chiral coordination polymers. Combining (R)-mandelic acid and 3,5-difluoromandelic acid with first row transition metals and dipyridyl co-ligands gives one-dimensional chains linked by hydrogen bonds into a densely packed structure. In contrast, the methoxy-protected analogue formed an open framework with solvent accessible channels. [ABSTRACT FROM AUTHOR]

The synthesis of three coordination polymers of cerium(III) and the ligand pyridine-2,4,6-tricarboxylate (PTC) is reported. Two of the materials crystallise under hydrothermal conditions at 180 °C, with [Ce(PTC)(H2O)2]·1.5H2O, (1), being formed on extended periods of reaction time, 3 days or longer, and Ce(PTC)(H2O)3, (2), crystallising after 1 day. Both phases contain Ce(III) but are prepared using the Ce(IV) salt Ce(SO4)2·4H2O as reagent. Under solvothermal conditions (mixed water-N,N-dimethylformamide (DMF)), the phase [Ce(PTC)(H2O)(DMF)]·H2O (3) is crystallised. The structures of the three materials are resolved by single crystal X-ray diffraction, with the phase purity of the samples determined by powder X-ray diffraction and thermogravimetric analysis. (1) is constructed from helical chains cross-linked by the PTC linkers to give a three-dimensional structure that contains clusters of water molecules in channels that are hydrogen-bonded to each other and to additional waters that are coordinated to cerium. (2) also contains nine-coordinate cerium but these are linked to give a dense framework, in which water is directly coordinated to cerium. (3) contains corner-shared nine-coordinate cerium centres, linked to give a framework in which Ce-coordinated DMF fills space. Upon heating the material (1) in air all water is irreversibly lost to give a poorly crystalline anhydrous phase Ce(PTC), as deduced from X-ray thermodiffractometry and thermogravimetric analysis. The material (1), however, is hydrothermally stable, and is also stable under oxidising conditions, where immersion in 30% H2O2 gives no loss in crystallinity. Oxidation of around 50% of surface Ce to the +4 oxidation state is thus possible, as evidenced by X-ray photoelectron spectroscopy, which is accompanied by a colour change from yellow to orange. Photocatalytic activity of (1) is screened and the material shows effective degradation of methyl orange. [ABSTRACT FROM AUTHOR]

This work describes the application of an unexplored aromatic tetracarboxylate building block, 2,3′,4,4′-diphenyl ether tetracarboxylic acid (H4deta), for the synthesis of manganese(II) and cadmium(II) coordination polymers (CPs). Five new products, formulated as [Mn2(μ6-deta)(phen)2]n (1), [Cd2(μ6-deta)(phen)2]n (2), [Mn2(μ6-deta)(2,2′-bipy)2]n (3), [Cd2(μ5-deta)(4,4′-bipy)2(H2O)2]n·2nH2O (4), and [Cd2(μ6-deta)(py)(H2O)2]n (5), were assembled using a hydrothermal protocol from the respective metal(II) chlorides, H4deta, and different mediators of crystallization, namely 1,10-phenanthroline (phen), 2,2′-bipyridine (2,2′-bipy), 4,4′-bipyridine (4,4′-bipy), or pyridine (py). All the CPs 1–5 were obtained as stable crystalline products and characterized by conventional solid-state methods (elemental analysis, FTIR, UV-vis, TGA, and PXRD) and single-crystal X-ray diffraction. The structures of 1–3 feature decorated honeycomb-like 2D double layers of a 3,6L66 topological type. Compound 4 reveals a trinodal 4,4,5-connected 3D metal–organic framework (MOF) with a unique topology, while the 2D coordination polymer 5 discloses a binodal 4,6-connected layer with a 4,6L45 topology. The structural and topological traits, thermal stability, luminescence properties and photocatalytic activity toward methylene blue degradation were studied for the obtained compounds. In particular, MOF 4 acts as an active, stable, and recyclable photocatalyst for the UV-light-assisted discoloration of methylene blue in water under ambient conditions. By introducing a novel type of flexible tetracarboxylic acid linker, the present study discloses the first manganese and cadmium compounds derived from H4deta as an unexplored polycarboxylate building block, thus contributing to intensive research on functional metal–organic architectures. [ABSTRACT FROM AUTHOR]

The use of acetic acid as neat solvent in the synthesis of coordination polymers using trimesic acid and metal acetates has been proved for different metals. 2D compact coordination polymers were obtained for cobalt, [Co 6 (BTC) 2 (Ac) 6 (HAc) 3 ], which incorporates both acetic acid and acetate ligands, and for bismuth, [Bi(HBTC)(Ac)]. Nowadays, there is a great interest in the design of new metal–organic frameworks (MOFs) synthetized by routes that can be transferred to industrial scale with low environmental impact. In this context, this work explores the use of a soft method for the synthesis of MOFs, in which neat acetic acid is used as the reaction media. Trimesic acid (H 3 BTC) was chosen as the organic linker source and combined with different metal acetates, all these precursor being moderately soluble in hot acetic acid. The metal acetate provides both the metallic cation and a base, the acetate, necessary to deprotonate the H 3 BTC. Three first row transition metals, Cu, Co and Ni, and one heavy metal, Bi, were chosen for the study. Results denoted that the metal acetate was determinant to direct the nature of the precipitated material. For instance, the precipitation of the well-known porous HKUST-1 was observed from Cu acetate and H 3 BTC in neat acetic acid, giving systems with hierarchical porosity. Contrarily, for Co and Bi the use of acetic acid as a solvent yielded two 2D non porous coordination polymers, [Co 6 (BTC) 2 (Ac) 6 (HAc) 3 ] (1) and [Bi(HBTC)(Ac)] (3), respectively. These new compounds were structurally elucidated. Moreover, the magnetic behaviour was analysed for the Co compound (1). Finally, an amorphous phase was precipitated for Ni. In the latter case, the use of propionic acid, with a higher boiling point than acetic acid, led to the precipitation of a crystalline material. [ABSTRACT FROM AUTHOR]

Luminescent coordination polymers (CPs) are known for their unique abilities to provide tunable emission processes originated at the interplay between their infinite inorganic and organic constituents combined in endless ways, thus yielding smart molecule‐scaled materials to be processed as photodevices, sensors, optical storage systems or even logic gates. Nonetheless, most of these applications demand the occurrence of persistent luminescence to prevent background interference with the fluorescence signal. This is the reason why attention has been recently shifted to CPs exhibiting long‐lasting phosphorescence (CP‐LLPs), which imbues these crystalline solids with a long‐lived emission that is traceable by the human eye. The large interest awakened by these materials opposes with their difficulty to being achieved compared to dominant fluorescent CPs, probably derived from their challenging design. In this microreview we give an overview of the CP‐LLPs reported so far with the aim of deciphering some hints that enable this behavior while their potential applications are also discussed. [ABSTRACT FROM AUTHOR]

Kinetic stabilisation of unstable chemical species in nanospace is of potential importance in the field of materials and synthetic chemistry, and porous coordination polymers (PCPs) represent a facile platform to provide such reaction fields. Thiyl radicals are important reactive substances that often play a leading role in organic and bioorganic chemistry. However, their generation in nanospace has been barely investigated due to synthetic difficulties. Here, we report a facile methodology for the functionalisation of active thiyl substituents on PCP pore surfaces using a post-synthetic protection and deprotection technique. The thiyl radicals were generated inside a zinc(ii)-based PCP upon the deprotection of asymmetric disulfides, which were used as the protecting groups by ultraviolet light irradiation. [ABSTRACT FROM AUTHOR]

Ancillary functionalization of a PCP pincer ligand with para -carboxylic acids provides a simple route to the subsequent preparation of crystalline coordination polymers using pre -cyclometallated complexes as polymer building blocks. This synthetic strategy is demonstrated here using air- and moisture-stable PCP-PdCl metalloligands to prepare new coordination polymers with both 1-D (chain) and 2-D (sheet) networks, named PCM-29 and PCM-30, respectively. The single crystal X-ray structures and solid-state gas sorption properties of both materials are presented. The Brunauer-Emmett-Teller (BET) surface area of PCM-30 was found to be 302 m 2 g −1 using CO 2 as the probe gas, indicating permanent porosity and reversible small molecule diffusion between the 2-D sheets. [ABSTRACT FROM AUTHOR]

Expansion and contraction of structurally flexible Metal–Organic Frameworks (MOFs) or Porous Coordination Polymers (PCPs) have been extensively studied from different structural and application perspectives including crystal engineering, structural characterization, and gas adsorption-separation applications. The flexibility of the MOFs or PCPs depends on a number of factors including the nature of secondary building units (SBUs), organic linkers, pore geometry and/or solvent molecules. The flexibility can lead to unique properties, especially in gas-adsorption-separation related applications that is not observed in rigid frameworks. In this review, we offer a brief summary regarding a fundamental understanding of framework expansion–contraction in flexible porous MOFs in terms of their design and structure tunability by covering representative examples in the literature. [ABSTRACT FROM AUTHOR]

A new coordination polymer, [Cd2(µ3-sip)2(etim)6Cd(etim)2]n (1) (sip = 5-sulfoisophtalate, etim = 2-ethylimidazole) has been synthesized and characterized by elemental analysis, spectral (FT-IR and photoluminescence) and thermal analysis. The structure of polynuclear complex 1 has been determined by the X-ray diffraction. Complexes 1 shows intense photoluminesent emission bands at 415 nm upon excitation at 319 nm. The emission of complex may be attributed to ligand centered luminescence emission. X-ray diffraction analysis of complex 1 reveals that it has a 1D polynuclear zig-zag chain. The 1D zig-zag chains in 1 are connected each other by N-H···O interaction and aromatic interaction between imidazole rings to form 3D supramolecular structure of 1. [ABSTRACT FROM AUTHOR]

Metal–organic frameworks (MOFs), also known as coordination polymers, have attracted extensive research interest in the past few decades due to their unique physical structures and potentially vast applications. In this review, we outline the recent progress in the synthesis, functionalization and applications of MOFs in biomedicine, mainly focusing on two promising, yet challenging areas, i.e., drug delivery and biosensing applications. A major challenge is the proper functionalization of MOFs with demanding properties suitable for biomedical applications. Extensive studies on MOFs in biomedicine have led to substantial progress in the control of key properties of MOFs such as toxicity, size and shape, and biological stability. Due to their flexible composition, pore size and easy functionalization properties, MOFs can be utilized as key components for the development of various functional systems, and their applications in drug delivery and biosensing are reviewed. Future trends and perspectives in these research areas are also outlined. [ABSTRACT FROM AUTHOR]

Metal–organic frameworks (MOFs) are porous coordination polymers linked by metal ions and ligands. With the progress of MOF research, many redox active MOFs have been synthesized by judicious selection of the electroactive metal ions and/or organic functional groups. Due to the unique properties (e.g., high surface areas, tailorable pore sizes, and exposed active sites), MOFs are found to have a wide range of redox activities to be applied in various fields (e.g., microporous conductors, electrocatalysts, energy storage devices, and electrochemical sensors). The potential of the MOFs composites has also been realized as ideal hosts for functional materials (like conducting nanoparticles). These composites are thus demonstrated to have superior electrocatalytic/electrochemical sensing properties than their pristine forms. Accordingly, various MOF composite-based platforms have been developed as efficient electrochemical sensors for environmental and biochemical targets. This review was organized to provide up-to-date information and insights into the fundamental aspects of MOF composites as electrocatalytic/electrochemical sensors. [ABSTRACT FROM AUTHOR]

Four new coordination polymers [Ni 2 (HL 1 ) 2 (L 1 ) 3 (BTC) 2 ]·6H 2 O ( 1 ), [Ni 2 (L 1 ) 3 (HBTC) 2 ]·4H 2 O ( 2 ), [Cd 2 (L 2 )(BTC)(H 2 O) 3 ]·2H 2 O ( 3 ) and [Cd 2 (HL 2 )(BTCA)] ( 4 ) were synthesized by reactions of nickel(II)/ cadmium(II) salts with rigid ligands of 1,4-di(1H-imidazol-4-yl)benzene (L 1 ), 1,3-di(1-imidazolyl)−5-(4H-tetrazol-5-yl)benzene (HL 2 ) and polycarboxylic acids of 1,3,5-benzenetricarboxylic acid (H 3 BTC), 1,2,4,5-benzenetetracarboxylic acid (H 4 BTCA), respectively. The structures of the complexes were determined by single crystal X-ray diffraction analysis. The complex 1 is one-dimensional (1D) chain while 2 is a (4, 4)-connected two-dimensional (2D) layered structure with 2D → 2D parallel interpenetration. Complex 3 is a rare tetranodal (3,4)-connected three-dimensional (3D) CrVTiSc architecture with Point (Schläfli) symbol of (4·8 2 )(4·8 4·10)(4 2·8 2·10 2 )(8 3 ), and compound 4 has the 2D network with (4,4) topology based on the [Cd 2 (COO) 4 ] SBUs. The weak interactions such as hydrogen bonds and π···π stacking contribute to stabilize crystal structure and extend the low-dimensional entities into high-dimensional frameworks. The UV–vis absorption spectra of 1 – 4 are discussed. Moreover, the photo luminescent properties of 3 and 4 and gas sorption property of 2 have been investigated. [ABSTRACT FROM AUTHOR]

Three novel coordination polymers, [Zn(μ 2 -HTCA)(Phen)] n ( 1 ), {[Cd(μ 3 -HTCA)(Phen)]·2H 2 O} n ( 2 ), [Mn(μ 2 -HTCA)(Phen)(H 2 O)] n ( 3 ) were prepared by hydrothermal synthesis from the 4, 4', 4''-nitrilotribenzoicacid (H 3 TCA) and 1, 10-phenanthroline monohydrate (Phen) with different transition metal salts, which were characterized by elemental analysis, IR spectra, powder and single-crystal X-ray diffraction and thermogravimetric analysis. The photophysical properties of the complexes were investigated by solid-state diffuse reflectance spectra, photoluminescent properties, lifetime and quantum yield. For these complexes, it was found that the band gaps follow the order: 3 ＜ 2 ＜ 1 ＜ 2.80 eV, fluorescence intensity order: 1 ＞ H 3 TCA ＞ 2 ＞ 3 ; quantum yield order: H 3 TCA ＞ 1 ＞ 2 ＞ 3 ; while the lifetime order: 1 ＞ 2 ＞ H 3 TCA ＞ 3 . [ABSTRACT FROM AUTHOR]

Selected recent examples of coordination polymers (CPs) or metal-organic frameworks (MOFs) constructed from different multifunctional carboxylic acids with phenyl-pyridine or biphenyl cores have been discussed. Despite being still little explored in crystal engineering research, such types of semi-rigid, thermally stable, multifunctional and versatile carboxylic acid building blocks have become very promising toward the hydrothermal synthesis of metal-organic architectures possessing distinct structural features, topologies, and functional properties. Thus, the main aim of this mini-review has been to motivate further research toward the synthesis and application of coordination polymers assembled from polycarboxylic acids with phenyl-pyridine or biphenyl cores. The importance of different reaction parameters and hydrothermal conditions on the generation and structural types of CPs or MOFs has also been highlighted. The influence of the type of main di- or tricarboxylate ligand, nature of metal node, stoichiometry and molar ratio of reagents, temperature, and presence of auxiliary ligands or templates has been showcased. Selected examples of highly porous or luminescent CPs, compounds with unusual magnetic properties, and frameworks for selective sensing applications have been described. [ABSTRACT FROM AUTHOR]

The aim of this review is to pay tribute to the legacy of O. Kahn. Kahn's credo was to synthesize magnetic compounds with predictable structure and magnetic properties. This is illustrated herein with results obtained by Kahn's group during his Orsay period thirty years ago, but also on the basis of our recent results on the synthesis of coordination polymers with oxamate ligands. The first part of this review is devoted to a short description of the necessary knowledge in physics and theoretical chemistry that Kahn and his group have used to select oxamate ligands, the complex‐as‐ligand strategy and the synthesis of heterobimetallic systems. Then, we describe the strategies we have later used to obtain the desired target compounds. The use of complexes as building‐blocks, associated to a control of the metal ions chirality and stoichiometry, allowed us to obtain coordination polymers with predictable dimensionality. For the synthesis of single‐chain magnets (SCMs) we show that the ligand chemical flexibility makes the isolation of the chains in the solid and the occurence of slow magnetic relaxation possible. For 1D and 2D molecule‐based magnets (MBMs), the magnetic ordering strongly depends on the interchain or interplane interactions, which are difficult to control. Again the flexibility of the oxamate ligands allowed their strengthening in the solid sate, yielding MBMs with critical temperatures up to 30 K. We will also present our results on 3D coordination polymers, particularly on the porous magnets displaying large octagonal channels. This family of porous MBMs possess outstanding chemical properties, such as post‐synthetic transformation in the solid state. Finally, we will also show that oxamate ligands allows the design of multifunctional materials, as in the case of the first chiral SCM. Overall, the results presented in this review show the impressive potential the oxamate ligands have for the design of coordination polymers. [ABSTRACT FROM AUTHOR]

Nowadays there is a high demand in specialized functional materials, for example, for applications as sensors in biomedicine. For the realization of such applications, nanostructures and the integration in a composite matrix are indispensable. Coordination polymers and networks, for example, with spin crossover properties, are a highly promising family of switchable materials in which the switching process can be triggered by various external stimuli. An overview over different strategies for the synthesis of nanoparticles of such systems is given. A special focus is set on the use of block copolymer micelles as templates for the synthesis of nanocomposites. The block copolymer defines the final size and shape of the nanoparticle core. Additionally it allows a further functionalization of the obtained nanoparticles by variation of the polymer blocks and an easy deposition of the composite material on surfaces. [ABSTRACT FROM AUTHOR]

Photo-functional infinite coordinated polymers (ICPs) were synthesized that consist of the photochromic dithienylethene (DTE) and a luminescent bridging unit to give enhanced fluorescence in the solid state. We could fabricate well-ordered micropatterns of these ICPs by a soft-lithographic method, which repeatedly showed high contrast on-off fluorescence switching. [ABSTRACT FROM AUTHOR]

Five 1-3D cadmium(II) coordination polymers, namely, [Cd(HL)(DMF)]n (1), [Cd4(HL)4(H2O)6]n (2), [Cd(HL)(phen)]n (3), [Cd2(HL)2(bpy)]n (4), and {[Cd3(HL)3(pbim)2]·H2O}n (5), have been synthesized and fully characterized [H3L = 2-(5-bromo-pyridin-3-yl)-1H-imidazole-4,5-dicarboxylic acid, DMF = N,N-dimethylformamide, phen = 1,10-phenanthroline, bpy = 4,4'-bipyridine, and pbim = 1,1'-(5-methyl-1,3-phenylene)bis(1H-imidazole)]. In those complexes, the doubly deprotonated H3L ligands and CdII ions display versatile coordination modes to construct various structures with interesting topologies. Complex 1 is a 2D helical structure with (4·82) topology built up from 3-connected (HL)2- and CdII nodes. Complex 2 containing (HL)2--bridged tetranuclear CdII subunits is a 3D helical structure where both (HL)2- and CdII adopt three coordination modes to form a rare 3-connected network with (5·8·12)2(5·12·16)2(5·82)(82·12) topology. Substituting the smaller terminal ligands DMF and water with the larger terminal ligand phen, (HL)2- ligands only use their imidazoledicarboxylate groups to bis-chelate CdII into a chain structure of 3. Complex 4 is a (3,4)-connected 3D network with (4·82)(4·82·103) topology built up from the (HL)2--bridged (4,82) mesolayer observed in 1 being further linked by rodlike bpy bridges replacing terminal ligand DMF. Complex 5 consists of (HL)2-- and pbim-bridged macrocycle chains and is a (3,4)-connected 2D novel network with (3·4·8)2(3·4·5·82·9)2(32·82·92) topology. As expected, the strongly bis-chelating coordination mode μ-kN,O:kN',O' of the imidazoledicarboxylate of (HL)2- absolutely dominates the assemblies with CdII in those complexes. Intriguingly, the additional ligands, such as smaller terminal ligands water and DMF, larger planar terminal ligand phen, as well as rodlike and V-shaped bridges bpy and pbim, exert obvious influence on the coordination modes of ligands (HL)2- and the resulting architectures. Clearly, larger terminal and bridging ligands phen and pbim could limit the coordination of the pyridyl of (HL)2- through steric hindrance. Meanwhile, the solid-state photoluminescence of those compounds at room temperature was also investigated, and the results indicate that their emissions are significantly influenced by the additional ligands incorporating into the networks. [ABSTRACT FROM AUTHOR]

Three novel coordination polymers, namely, {[Pr(TTTPC)·(H 2 O) 2 ]·2Cl·NO 3 ·4H 2 O} n ( I ), {[Gd(TTTPC)·(H 2 O) 2 ]·2Cl·NO 3 ·4H 2 O} n ( II ) and {[Yb(TTTPC)·(H 2 O) 2 ]·3Cl·NO 3 ·0.5DMA·6H 2 O} n ( III ) were synthesized in conventional aqueous solutions with H 3 TTTPC ligands (H 3 TTTPC = 1,1′,1″-(2,4,6-trimethylbenzene-1,3,5-triyl(methylene))-tris(pyridine-4-carboxylic acid), DMA = N,N -dimethylacetamide) and characterized by infrared spectrometry and single crystal X-ray diffraction. Experimental results show that these MOFs are isomorphous and isostructural, containing the unit of cavate 14-membered cages (Pr 2 (OCO) 4 ), based on which to generate a one-dimensional (1D) infinite linear metallic chain through the linkage of two COO − groups that are further interlinked reciprocally to polymerize into three-dimensional (3D) porous frameworks. Coordination polymer III shows remarkable selectivity toward Pb 2+ and it can be considered as potential selective luminescent probes for Pb 2+ ion. Additionally, magnetic analysis indicates coordination polymer I presents antiferromagnetism. Besides, lanthanide contraction effect exists in as-synthesized coordination polymers. [ABSTRACT FROM AUTHOR]

Controllable synthesis of coordination polymer (CP) isomers and revealing their structure-property relationships remain enormous challenges. Three new supramolecular isomers have been synthesized by tuning the poly(ethylene glycol) (PEG) content in the feed. These supramolecular isomers have the same framework formula of [Cu2I2(tppe)] and different architectures from the classical 2D stacking framework to a 3D entangled system with the coexistence of interpenetration and polycatenation, and a 3D topological framework. Interestingly, these CPs could be utilized for capturing iodine molecules. According to multiple complementary experiments and crystallographic analyses, iodine capture is mainly based on halogen-bond interactions in the inorganic {Cu2I2} building blocks of the framework. The present study describes a structure-property relationship in supramolecular isomerism with distinct topological structures. [ABSTRACT FROM AUTHOR]

Metal coordination and peptide-directed self-assembly are two proven methods for creating defined supramolecular architectures. Here, we report a new class of crystalline materials based on coiled-coil peptides bearing unnatural metal-chelating terpyridine moieties. High-resolution structural characterization of lattices formed in the presence of Cu2+ reveals a general assembly mechanism. Subtle sequence variation in the modular synthetic ligand dictates assembly morphology. [ABSTRACT FROM AUTHOR]

One new Co-based coordination polymer with a bidentate imidazole ligand, 4,4′-bisimidazolylbiphenyl (4,4′-bibp), and a 1,4-benzenedicarboxylate (1,4-bdc) co-ligand, [Co(bibp)(bdc)] n ( 1 ) has been synthesized under hydrothermal conditions. For complex 1 , the mixed ligands linked the Co(II) ions to form a three dimensional 4-connected net with a rare dmp topology, in which a large cavity causes 3-fold interpenetration of the network. Dye adsorption studies confirmed that 1 can selectively adsorb the organic dyes methyl orange, methyl blue, neutral red, Sudan I and methylene blue, but hardly adsorb Safranine T. [ABSTRACT FROM AUTHOR]

The synthesis of coordination polymers or metal-organic frameworks (MOFs) has attracted considerable interest owing to the interesting structures and potential applications of these compounds. It is still a challenge to predict the exact structures and compositions of the final products. A new one-dimensional coordination polymer, catena-poly[[[bis{1-[(1 H-benzimidazol-2-yl)methyl]-1 H-tetrazole-κ N3}zinc(II)]-μ-hexane-1,6-dicarboxylato-κ4 O1, O1′: O6, O6′] monohydrate], {[Zn(C6H8O4)(C9H8N6)2]·H2O} n, has been synthesized by the reaction of Zn(Ac)2 (Ac is acetate) with 1-[(1 H-benzimidazol-2-yl)methyl]-1 H-tetrazole (bimt) and adipic acid (H2adi) at room temperature. In the polymer, each ZnII ion exhibits an irregular octahedral ZnN2O4 coordination geometry and is coordinated by two N atoms from two symmetry-related bimt ligands and four O atoms from two symmetry-related dianionic adipate ligands. ZnII ions are connected by adipate ligands into a one-dimensional chain which runs parallel to the c axis. The bimt ligands coordinate to the ZnII ions in a monodentate mode on both sides of the main chain. In the crystal, the one-dimensional chains are further connected through N-H...O hydrogen bonds, leading to a three-dimensional supramolecular architecture. In addition, the title polymer exhibits fluorescence, with emissions at 334 and 350 nm in the solid state at room temperature. [ABSTRACT FROM AUTHOR]

Three interesting metal-organic frameworks, [(Cd 2 (Hpidc)(pdc)] n (1), {[(Cd 2 (Hpidc) 2 (H 2 O)]·H 2 O} n (2), {[(Cd 2 (Hpidc) 2 (H 2 O)]·2H 2 O} n (3) (H 3 pidc = pyridine-2-yl-1H-imidazole-4,5-dicarboxylic acid, H 2 pdc = 2,6-pyridine dicarboxylic acid) have been synthesized under hydrothermal by controlling the temperature and varying with the second organic ligands. Compounds 1 and 2 possess 3D frameworks with a new topological network with 2-nodal (6, 6)-connected net and 2-nodal (5, 6)-connected net respectively. Notably, Compound 3 exhibit a 1-D interesting double Zigzag chain. The thermogravimetric and fluorescence properties of 1–3 were also explored. [ABSTRACT FROM AUTHOR]

Two isostructural 3D europium metal–organic frameworks incorporating similar Eu-fluorine substituted carboxylate tectonics, {[Eu 4 (Mimda) 4 (Tfpa) 2 ·4H 2 O]} n ( 1 ) and {[Eu 4 (Pimda) 4 (Tfpa) 2 ·4H 2 O]} n ( 2 ) (Mimda = 2-methyl-1H-imidazole - 4, 5–dicarboxy acid, while Pimda = 2-propyl-1H-imidazole - 4, 5–dicarboxy acid and Tfpa = (3,4,5,6-tetrafluoro-1,2 phthalate acid) have been synthesized under the hydrothermal conditions. They have been systematically characterized by elemental analyses, IR spectra and PXRD patterns. Single crystal X-ray diffraction analysis reveals that each polymer possesses infinite rod-shaped chain consist of dinuclear Eu-carboxylate building units, which are further pillared by imidazole-dicarboxylate ligands to give rise to 3D open non-interpenetrated frameworks, featuring a (6, 4)-connected pseudo-primitive cubic (pcu) topology. Both two polymers exhibit efficiently sensitized red luminescence due to an energy transfer from substituted dicarboxylate ligand to Eu(III) ions in solid state. Polymer 1 also demonstrates tunable or switchable fluorescence signals in response to the different solvents. Moreover, the luminescent intensity of 1 is increased linearly with the increasing concentration of Pb 2 + cation in N , N -dimethyl formamide (DMF) suspension, while shows declining trend with Cd 2 + cation being introduced. [ABSTRACT FROM AUTHOR]

The results of our studies on the synthesis of porous metal-organic coordination polymers (including homochiral frameworks) based on 3 d-metal cations and bridges of two types (carboxylate and N-donor ligands) and investigations of their sorption and catalytic properties are summarized in the review. [ABSTRACT FROM AUTHOR]

Three new mixed-ligand metal-organic frameworks based on 5,5′-(butane-1,4- diyl)-bis(oxy)-diisophthalic acid and transitional metal cations with the help of two ancillary bridging N-donor pyridyl and imidazole linkers, [Zn(L) 0.5 (4,4′-bpy)]·2(H 2 O) (1), [M(L) 0.5 (bib)]·4(H 2 O) (M = Zn (2), Co (3) ), (4,4′-bpy=4,4′–bipyridine, bib=1,4-bis (1H-imidazol-1-yl)-butane), have been synthesized under solvothermal conditions. Their structures and properties were determined by single-crystal and powder X-ray diffraction analyses, IR spectra, elemental analyses and thermogravimetric analyses (TGA). Compounds 1 – 3 display a 3D 3-fold interpenetrated frameworks linked by the L 4− ligands, ancillary N-donor linkers and the free water molecules in the crystal lattice. Topological analysis reveals that 1 – 3 are a (4,4)-connected bbf topology net with the (6 4 ·8 2 )(6 6 ) topology. The effects of the L 4− anions, the N-donor ligands, and the metal ions on the structures of the coordination polymers have been discussed. Furthermore, luminescence properties and thermogravimetric properties of these compounds were investigated. [ABSTRACT FROM AUTHOR]

A novel transition metal–organic framework, [Ni 2 ( μ 4 -btca)(1,4-bib) 2 (H 2 O) 2 ] n , was obtained by the hydrothermal reaction of nickel chloride hexahydrate, 1,2,4,5-benzenetetra-carboxylic acid (H 4 btca) and 1,4-bis(1H-imidazol-4-yl)benzene (1,4-bib) in an ethanol aqueous solution. The composition and structure of the complex were characterized by elemental analyses, single crystal X-ray diffraction analysis, Fourier transform infrared spectroscopy, thermogravimetry and differential scanning calorimetry. The complex crystallizes in the triclinic system with the P 1 ‾ space group. Each nickel(II) ion is hexacoordinated in a 2N4O mode and has a slightly distorted octahedral geometry. The thermal decomposition of the complex includes dehydration and pyrolysis of the ligands, and the final residue is nickel oxide. The magnetic property of the complex has been studied by variable temperature magnetic susceptibility measurements, and it possesses weak antiferromagnetic interactions. [ABSTRACT FROM AUTHOR]

A new coordination polymer of [Mn(SO)( L)·(HO)] was synthesized by the interaction of a big π-conjugated rigid ligand 1,4-bis([1,10]phenanthroline-[5,6-d]imidazol-2-yl)benzene( L) and manganese sulfate, exhibiting a eightfold interpenetrated diamondoid network. In addition, the thermal stability and luminescence property of the complex have been studied in this work. [ABSTRACT FROM AUTHOR]

This paper describes the hydrothermal synthesis, full characterization, and architectural diversity of three intriguingly bioactive cobalt-organic frameworks, namely, 3D [Co( HL)(BPY)]·4 nHO ( 1), 2D [Co( HL)(BPE)] ( 2), and 2D [Co( HL)(DPP)] ( 3) coordination polymers, synthesized through a mixed ligand strategy using H L (1-H-indazole-3-carboxylic acid) as a main structural block and the flexible bipyridine and its derivatives (BPY = 4,4′-bipydine, BPE = 1,2-bis(4-pyridyl)ethane, DPP = 1,3-bis(4-pyridyl)propane) as auxiliary ligand sources. Complexes 1- 3 were isolated as air stable and slightly soluble crystalline solids and characterized using elemental analysis, FT-IR, electrochemical technique, thermogravimetric analysis, powder X-ray diffractometer, and single-crystal X-ray crystallography. The bipyridine derivatives played key roles in defining the structural space group and dimensionality feature of the obtained networks. The abundant H-bonding and π- π stacking interactions in complexes 1- 3 gave rise to their intricate metal-organic structures of 3D ( 1), 2D ( 2), and 2D ( 3). In addition, the solutions of complexes 1- 3 showed profound antifungal activities against the selected strain of Colletotrichum musae compared with the controlled group using benomyl as a traditional agrochemical fungicide. [ABSTRACT FROM AUTHOR]

The booming development of homochiral metal–organic frameworks (HMOFs) since the start of the 21st century has attracted considerable attention from the scientific community. With the features inherited from MOFs, HMOFs have great potential for application in gas storage, separation, sensing, catalysis, ferroelectric materials and nonlinear optics. Moreover, they show incomparable potential in enantioseparation and asymmetric catalysis, which are emergent technologies in modern chemical engineering. In this highlight, we summarize the classical ways to construct HMOFs based on the selection of ligands, as well as the practical techniques utilized. Moreover, the merits and demerits of each method are discussed along with the predictability of homochirality. [ABSTRACT FROM AUTHOR]

Two new coordination polymers, {[Cd(BIDPT)(oba)]·0.5H 2 O} n ( 1 ) and {[Zn(BIDPT)(4,4′-sdb)]·2.25H 2 O} n ( 2 ) (BIDPT = 4,4′-bis(imidazol-l-yl)diphenyl thioether, H 2 oba = 4,4′-oxydibenzoic acid, 4,4′-H 2 sdb = 4,4′-sulfonyldibenzoic acid), have been solvothermally synthesized and characterized. Both 1 and 2 show 2-fold interpenetrating 3D frameworks with {6 5 ∙ 8} cds and {6 6 } dia topology, respectively. These two coordination polymers show strong luminescence and their luminescence could be quenched by a series of nitro explosives. Importantly, they exhibit very highly sensitive and selective detection of picric acid compared to other nitro explosives. [ABSTRACT FROM AUTHOR]

By using pyridyl derivatives 4-cyanopyridine (4-pyCN) or nicotinate (na−) as terminal ligands (LT) to decorate the flexible trigonal-prismatic trinuclear metal carboxylate M3(μ3-O/μ3-OH)(RCOO)6(LT)3 clusters, a theoretically predicted uninodal 6-connected flu-e network for [M3(μ3-O/μ3-OH)(bdc)3(LT)3] (H2bdc = 1,4-benzenedicarboxylic acid) has been realized in three new porous coordination frameworks. The flu-e topology is isomeric to the uninodal 6-connected acs (MIL-88) and tetranodal 6-connected mtn-e (MIL-101) ones observed in the classic metal carboxylate framework materials, but comprises of unique cubic cages which require exceptional conformation for the trinuclear clusters. The weak coordinating 4-pyCN terminal ligands tend to leave the clusters during thermal activation, leading to framework distortion and reduction of the long-range order of the flu-e network, which can only be restored by 4-pyCN instead of other guest molecules. On the other hand, the carboxylate ends of the adjacent na− ligands coordinate with additional metal ions to crosslink the coordination networks as new binodal 4,9-connected networks with remarkably enhanced thermal/chemical stability and porosity. [ABSTRACT FROM AUTHOR]

Two new coordination polymers have been synthesized with 2,5-furandicarboxylic acid upon base modification. The resulting structures are dependent on the base added. When KOH was used as base, potassium was incorporated into the two-dimensional coordination polymer, acting as a metallolinker to give [Pr2K2(OH)2(C6H2O5)3(H2O)3] ·H2O ( 1). Synthesis with other alkali hydroxides produced a three-dimensional metal-organic framework, [Pr8(OH)6(C6H2O5)9(H2O)15] ·3H2O ( 2), and the alkali metal cations were not incorporated into the structure. Hole-size effects with bite-angle analyses indicate that metallolinker formation depends on the cation size. The resulting compounds were characterized by single-crystal X-ray diffraction, powder X-ray diffraction, elemental analysis, and thermogravimetric analysis. [ABSTRACT FROM AUTHOR]

The synthesis and characterisation of five coordination polymers – Ni2(mip)2(H2O)8·2H2O (1), Zn6(mip)5(OH)2(H2O)4·7.4H2O (2), Zn6(mip)5(OH)2(H2O)2·4H2O (3), Mn(HMeOip)2 (4), and Mn3(tbip)2(Htbip)2(EtOH)2 (5) – are reported. Preliminary nitric oxide release data on compounds 2 and 3 are also given. [ABSTRACT FROM AUTHOR]

A porous crystalline corannulene-containing scaffold, which combines the periodicity, dimensionality, and structural modularity of hybrid frameworks with the intrinsic properties of redox-active π-bowls, has been prepared. Single-crystal and powder X-ray diffraction, ab initio density functional theory computations, gas sorption analysis, fluorescence spectroscopy, and cyclic voltammetry were employed to study the properties of the novel corannulene derivatives and the buckybowl-based hybrid materials. X-ray diffraction studies revealed the preservation of the corannulene bowl inside the prepared rigid matrix, which offers the unique opportunity to extend the scaffold dimensionality through the buckybowl curvature. Merging the inherent properties of hybrid frameworks with the intrinsic properties of π-bowls opens a new avenue for preparing redox-active materials and potentially improving charge transport in the scaffold. [ABSTRACT FROM AUTHOR]

Bimetallic coordination polymers (BiCPs) with Zn and Co were synthesized and applied as anode materials. When the rate was increased to 2 A g−1, a capacity of 622 mA h g−1 after 500 cycles could still be maintained. [ABSTRACT FROM AUTHOR]

By incorporating co-ligands 1,2-bis(imidazol-1-ylmethyl)benzene (1,2-bix), 1,3-bis(imidazol-1-ylmethyl)benzene (1,3-bix) and 1,4-bis(imidazol-1-ylmethyl)benzene (1,4-bix), three isomeric cobalt phosphonates Co5(1,2-bix)2(pbtc)2(H2O)4·8H2O (1), Co5(1,3-bix)2(pbtc)2(H2O)4·7.5H2O (2), and Co5(1,4-bix)2(pbtc)2(H2O)4·6H2O (3) (pbtcH5 = 5-phosphonatophenyl-1,2,4-tricarboxylic acid) have been isolated successfully. Compound 1 shows a layer structure in which chains containing alternately arranged Co3O2 trimers and Co2 dimers are connected by pbtc5− ligands. The 1,2-bix co-ligand adopts a cis-mode, and coordinates to the cobalt atoms from the same chain. Upon dehydration, compound 1 undergoes single-crystal-to-single-crystal (SC–SC) structural transformation forming a new crystal phase Co5(1,2-bix)2(pbtc)2(H2O)4 (1a). The process is reversible upon rehydration, showing a breathing effect. In compounds 2 and 3, similar layers composed of cobalt phosphonate chains and pbtc5− linkages are also found, which are further cross-linked by 1,3-bix or 1,4-bix to form 3D framework structures. The three compounds show different microporosities, as confirmed by their different N2 gas adsorption behaviors. [ABSTRACT FROM AUTHOR]

In this paper, two novel metal-organic frameworks [Cu(bna1)(DMF)]n·nH2O·nCH3OH (complex1) (H2bna1= 2,2′-dihydroxy-1,1′-dinaphthyl-6,6′-dicarboxy acid) and [Co(bna2)2(bpy)(H2O)2]n(complex2) (H2bna2= 2,2′-dihydroxy-1,1′-Dinaphthyl-4,4′-dicar–boxyacid) have been synthesized under mild conditions and carefully characterized. Crystal structural analysis reveals that complex1adopts a 1D infinite chain structure, which forms 2D sheet by π–π weak interactions. Complex2possesses 2D sheet structure, where Cobalt ions are recognized as the nodes. So it generated a regular two-dimensional grid with the size of 1.57 × 1.15 nm. Complex2assembles into a 3D supramolecular network connected by the hydrogen bonds. IR spectra studies indicate that the coordination mode of carboxyl group of complex1and complex2are chelating with the metal ions. X-ray powder diffraction (PXRD) studies of both complexes confirm that there is no impurity phase in both complexes since their diffraction patterns match well with the simulated ones. [ABSTRACT FROM PUBLISHER]

{[Cu 4 (μ-bpe) 4 Cu 2 (μ-pydc) 2 (μ 3 -pydc) 2 ]·14H 2 O} n ( 1 ) and [Cu(pydcH) 2 (bpe) 2 ] ( 2 ) have been solvothermally synthesized by 1,2-bis(4-pyridyl)ethylene (bpe) along with dianionic pyridine-2,3-dicarboxylate (pydc) ligands and characterized by elemental, FT-IR and thermal analyses techniques. In the solvothermal synthesis of complexes, 1 was isolated when the reactor was opened whereas 2 was crystallized after 3 weeks. The X-ray crystallographic studies show that complex 1 exhibits ladder-like structure involving mixed-valence Cu(I,II) which has generated a simultaneous in situ redox reaction and a unique 14-membered water cluster consisting of an eight-membered open-cube hexamer and two cyclic water trimers has been observed in hydrophilic cavities of 1 . Supramolecular network of 2, which has proton transfer product of pydcH cations, is formed by O–H···N and aromatic interactions. [ABSTRACT FROM AUTHOR]

Open-framework materials, such as metal-organic frameworks (MOFs) and coordination polymers have been widely investigated for their gas adsorption and separation properties. However, recent studies have demonstrated that their highly crystalline structures can be used to periodically organize guest molecules and non-structural metal compounds either within their pore voids or by anchoring to their framework architecture. Accordingly, the open framework can act as a matrix for isolating and elucidating the structures of these moieties by X-ray diffraction. This concept has broad scope for development as an analytical tool where obtaining single crystals of a target molecule presents a significant challenge and it additionally offers potential for obtaining insights into chemically reactive species that can be stabilized within the pore network. However, the technique does have limitations and as yet a general experimental method has not been realized. Herein we focus on recent examples in which framework materials have been utilized as a scaffold for ordering molecules for analysis by diffraction methods and canvass areas for future exploration. [ABSTRACT FROM AUTHOR]

An unusual 1D-to-3D transformation of a coordination polymer based on organic linkers containing highly polar push-pull π-conjugated side chains is reported. The coordination polymers are synthesized from zinc nitrate and an organic linker, namely, 2,5-bis{4-[1-(4-nitrophenyl)pyrrolidin-2-yl]butoxy}terephthalic acid, which possesses highly polar (4-nitrophenyl)pyrrolidine groups, with high dipole moments of about 7 D. The coordination polymers exhibit an unusual transformation from a soluble, solvent-stabilized 1D coordination polymer into an insoluble, metal-organic framework (MOF)-like 3D coordination polymer. The coordination polymer exhibits good film-forming ability, and the MOF-like films are insoluble in conventional organic solvents. [ABSTRACT FROM AUTHOR]

Two new interpenetrated MOFs based on flexible 1,3-bis(2-methylimidazolyl)propane and rigid isophtalic (1,3-benzenedicarboxylic) acid were obtained. Structure of both compounds were determined by single-crystal X-Ray analysis. The photoluminescence at room temperature of the compounds 1 and 2a were also investigated in the solid state. Quantum yields (QY) of luminescence for 1 and 2a are 30.5% and 39.8% correspondingly. [Display omitted] The synthesis of new coordination polymers based on flexible ligands is a challenging task. The use of two types of ligands is a possible approach to obtain crystalline compounds. The combination of flexibility and rigidity can lead to unusual topologies and properties. We are managed to obtain two new metal–organic frameworks (MOFs) based on flexible 1,3-bis(2-methylimidazolyl)propane and rigid isophtalic (1,3-benzenedicarboxylic) acid: [Zn 2 (iph) 2 (bmip) 2 ] (1) and [Zn 4 (iph) 4 (bmip) 3 ]·2DMF·3.5H 2 O (2). Structure of both compounds were determined by single-crystal X-ray analysis. Compound 1 is 3-fold interpenetrating 3D framework with dmp topology. Compound 2 is 2-fold interconnecting 3D framework with rare topology, described as (4,6)-c net. Compound 2 contains guest DMF and water molecules. Interestingly, compound 2 easily loses guest molecules in air and undergoes to another crystalline compound 2a. The photoluminescence at room temperature of the compounds 1 and 2a were investigated in the solid state. Quantum yields (QY) of luminescence for 1 and 2a are 30.5% and 39.8%, respectively. The short decay times are allowed to attribute the emission to fluorescence characteristic for intraligand transitions. [ABSTRACT FROM AUTHOR]

The sorption of CO, CO2 and C2H2 by two urotropine-containing porous metal–organic framework materials [Zn4(dmf)(ur)2(ndc)4] (H2ndc = 2,6-naphthalenedicarboxylic acid; ur = urotropine; dmf = dimethylformamide) and [Zn11(H2O)2(ur)4(bpdc)11] (H4bpdc = 4,4′-biphenyldicarboxylic acid) incorporating free N-donors has been investigated. These materials show pronounced affinity for CO2 and C2H2, and these observations are supported by interaction energy and ab initio DFT calculations. [ABSTRACT FROM AUTHOR]

A luminescent homochiral uranyl succinate coordination polymer with unprecedented three-directional helices was synthesized hydrothermally via spontaneous symmetry breaking, and fully characterized. Its homochirality has been confirmed by singe crystal X-ray diffraction and solid state circular dichroism (CD) spectra. The polymer exhibited a Stokes shift greater than 180 nm. [ABSTRACT FROM AUTHOR]

Four metal–organic coordination polymers [Zn(HL)(H 2 O)]·4H 2 O ( 1 ), [Zn(HL)(L 1 )]·4H 2 O ( 2 ), [Cu(HL)(H 2 O)]·3H 2 O ( 3 ) and [Cu(HL)(L 1 )]·5H 2 O ( 4 ) were synthesized by reactions of the corresponding metal(II) salts with semirigid polycarboxylate ligand (5-((4-carboxypiperidin-1-yl)methyl)isophthalic acid hydrochloride, H 3 L·HCl) or auxiliary ligand (1,4-di(1 H -imidazol-4-yl)benzene, L 1 ). The structures of the compounds were characterized by elemental analysis, FT-IR spectroscopy and single-crystal X-ray diffraction. The use of auxiliary ligand L 1 has great influence on the structures of two pairs of complexes 1 , 2 and 3 , 4 . Complex 1 is a uninodal 3-connected rare 2-fold interpenetrating ZnSc net with a Point (Schlafli) symbol of (10 3 ) while 2 is a one-dimensional (1D) ladder structure. Compound 3 features a two-dimensional (2D) honeycomb network with typical 6 3 -hcb topology, while 4 is 2D network with (4, 4) sql topology based on binuclear Cu II subunits. The non-covalent bonding interactions such as hydrogen bonds, π···π stacking and C–H··· π exist in complexes 1 – 4 , which contributes to stabilize crystal structure and extend the low-dimensional entities into high-dimensional frameworks. And the photoluminescent property of 1 and 2 and gas sorption property of 4 have been investigated. [ABSTRACT FROM AUTHOR]

Rationalization of the synthetic conditions allowed the predictable fast sustainable preparation of [La2(H3nmp)2(H2O)4]·4.5H2O having a 1D coordination polymer. The material exhibits a remarkable chemical stability, can be converted into other layered compounds, and is an excellent catalyst surpassing other related materials. [ABSTRACT FROM AUTHOR]

Presented here is a new heterometallic coordination polymer, namely [ZnCa(btec)(HO)] ( 1 Hbtec = 1,2,4,5-benzenetetracarboxylic acid), which was successfully synthesized via the hydrothermal reactions of Hbtec, Zn(NO) and CaCl. Single crystal X-ray structural analysis reveals that compound 1 features a 3D inorganic-organic hybrid framework, which can be simplified into a (4,8)-connected scu topological network by viewing Zn(II) ions, Ca(II) ions, btec ligands as 4-, 4-, and 8-connected nodes, respectively. Moreover, the luminescent properties of compound 1 and the desolvated samples were also investigated at room temperature. [ABSTRACT FROM AUTHOR]