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In this work, we report on five novel coordination polymers (CPs) based on the linkage of the [Cd(6apic)2] building block [where 6apic = 6-aminopicolinate] by different bipyridine-type organic spacers, forming different coordination compounds with the following formulae: [Cd(μ-6apic)2]n (1), {[Cd(6apic)2(μ-bipy)]·H2O}n (2), {[Cd(6apic)2(μ-bpe)]·2H2O}n (3), [Cd(6apic)(μ-6apic)(μ-bpa)0.5]n (4) and {[Cd2(6apic)4(μ-tmbp)]·7H2O}n (5) [where bipy = 4,4′-bipyridine, bpe = 1,2-di(4-pyridyl)ethylene, bpa = 1,2-di(4-pyridyl)ethane (bpa) and tmbp = 1,3-di(4-pyridyl)propane]. Most of the synthesized compounds form infinite metal–organic rods through the linkage of the building block by the bipyridine-type linker, except in the case of compound 4 whose assembly forms a densely packed 3D architecture. All compounds were fully characterized and their photoluminescence properties were studied experimentally and computationally through density functional theory (DFT) calculations. All compounds display, upon UV excitation, a similar blue emission of variable intensity depending on the linker employed for the connection of the building units, among which compound 2 deserves to be highlighted for its room temperature phosphorescence (RTP) with an emission lifetime of 32 ms that extends to 79 ms at low temperature. These good photoluminescence properties, in addition to its stability in water over a wide pH range (between 2 and 10), motivated us to study compound 2 as a sensor for the detection of metal ions in water, and it showed high sensitivity to Fe3+ through a fluorescence turn-off mechanism and an unspecific turn-on response to Zn2+. Furthermore, the compound is processed as a paper-based analytical device (PAD) in which the phosphorescence emission is preserved, improving the sensing capacity toward Fe3+ ions. [ABSTRACT FROM AUTHOR]

The combination of electron-deficient viologen ligands with electron-rich POMs is a typical acceptor–donor system that has recently received much attention. Under solvothermal and hydrothermal conditions, by introducing three symmetric viologen ligands into POM-based hybrid materials, we successfully constructed four POMs–viologen inorganic–organic hybrid compounds, namely (1,3-bcbpy)2·(δ-Mo8O26) (1) (1,3-bcbpy·2Cl = 1,1′-bis(3-carboxybenzyl)-4,4′-bipyridine dichloride), {CoII(1,4-bcbpy)2(H2O)2[H2(β-Mo8O26)]}·2H2O·2CH2O (2), (1,4-bcbpy)2·(δ-Mo8O26)·2H2O (3) (1,4-bcbpy·2Cl = 1,1′-bis(4-carboxybenzyl)-4,4′-bipyridine dichloride, CH2O = formaldehyde), and {CuII(1,1-pmbby)2(H2O)[H2(β-Mo8O26)2]}·5H2O·C2H7N (4) (1,1-pmbby·2Cl = 1,1′-[1,4-phenylbis(methylene)]bis-(4,4′-bipyridine)dichloride, C2H7N = dimethylamine). These four compounds exhibit different fascinating structures, especially compound 4 is a typical metal–organic framework. Compounds 1–4 exhibit good discoloration behaviors under various external stimuli. For example, compounds 1–4 showed a positive response to the irradiation from a 300 W Xe lamp. When a positive voltage was applied to the ECD based on compounds 1–4, 1/2/3/4-ECD underwent a significant color conversion. What's more, compound 4 also showed obvious discoloration results after heating. In a word, 1–4 are multifunctional discoloration materials under different external stimuli. In addition, the coated filter paper prepared based on compound 3 can be used as a new printing material medium and can be successfully applied in erasable inkless printing and dual anti-counterfeiting. [ABSTRACT FROM AUTHOR]

This document is a contents list for the journal "Dalton Transactions: An International Journal of Inorganic Chemistry." It provides a list of research papers published in the journal in 2024. The topics covered in these papers include carbon-based photoelectrochemical sensors, catalytic dehydrogenation of n-alkanes, metal-organic frameworks, and coordination polymers. The journal aims to foster connections within the global chemistry community and welcomes contributions from scientists at all career stages and countries. One of the papers explores the regulation of thermal expansion in a specific layer through axial coordination and dimensional reduction. Another paper investigates the synthesis, structure, and magnetic properties of one-dimensional lanthanide coordination polymers. The third paper focuses on the structural engineering of hollow nanorods with high-performance peroxidase-like activity for colorimetric detection. [Extracted from the article]

The document is a contents list for the journal "Dalton Transactions: An International Journal of Inorganic Chemistry," published by The Royal Society of Chemistry. It features articles and papers on various topics, including synthetic routes and chemical structural analysis for new Pt(II) metallodrug design and the synthesis and reactivity of air stable Ni(II) complexes. The correction notice in the document acknowledges an error in the original publication of a study on the reactivity of a Lewis superacidic carborane-based compound towards Lewis bases, authored by Libo Xiang, Alexander Matler, Leibo Tan, and Qing Ye. The notice provides the correct page number for the article. [Extracted from the article]

This document is a contents list for the journal "Dalton Transactions: An International Journal of Inorganic Chemistry." It features a compilation of research papers covering various topics such as metal dioxo complexes, piezo-photocatalytic CO2 reduction, and carbonaceous materials for lithium-ion batteries. The journal aims to foster connections within the chemistry community and stimulate innovative ideas. Additionally, the document includes corrections to two previously published papers. [Extracted from the article]

The document is a contents list for the journal "Dalton Transactions: An International Journal of Inorganic Chemistry." It includes various articles and papers on topics such as copper complexes, lanthanide-based POMs, and coordination polymers. The journal is published by The Royal Society of Chemistry, a leading chemistry community. The document also mentions approved training courses offered by the society. The given document is a list of papers published in the journal Dalton Transactions. The papers cover a range of topics in chemistry, including catalysis, phosphors, materials synthesis, and more. Each paper is identified by its title, authors, and page number. The document also includes a correction and a retraction for two previously published papers. [Extracted from the article]

The document is a contents list for the journal "Dalton Transactions: An International Journal of Inorganic Chemistry." It features articles and papers on a wide range of topics, including organometallics in molecular junctions and the synthesis of different compounds and their properties. The journal aims to promote the chemical sciences and reinvest its profits into the chemistry community. One of the articles, titled "Fedushkin," is a scientific journal published by The Royal Society of Chemistry in 2024. It provides valuable research and findings on various aspects related to the subject of Fedushkin, which may be of interest to library patrons conducting research in this field. [Extracted from the article]

Two isomorphous 3D Mn(II) and Co(II) coordination polymers with a dicarboxylate inner salt and cyanate as coligands were synthesized and structurally characterized, and their magnetic properties have been studied. In the compounds, [M(L)(NCO)]n·nH2O (M = Mn, Co, L = 1-carboxymethylpyridinium-4-carboxylate), neighboring metal ions are linked by the 3-fold bridges of an end-on cyanate and two syn–syncarboxylate bridges to give an anionic chain of [M(µ-NCO)(µ–COO)2]n, and each chain is interlinked to four other chains by the cationic 1-methylpyridinium spacers to generate a 3D structure with the 42· 63· 8 net topology. They are the first compounds with mixed cyanate and carboxylate bridges. Magnetic studies reveal that the 3-fold mixed bridge propagates antiferromagnetic coupling in the Mn(II) compound but ferromagnetic coupling in the Co(II) compound. The rather complex magnetic behaviors of the Co(II) compound are analyzed taking into account the first-order spin-orbital coupling and the intrachain ferromagnetic interactions. [ABSTRACT FROM AUTHOR]

The document is a contents list for the journal "Dalton Transactions: An International Journal of Inorganic Chemistry." It includes a range of articles on various topics related to inorganic chemistry, such as electrocatalysts for water splitting, phosphors for backlight display applications, and metal-organic compounds in sensing and catalysis. The journal is published by The Royal Society of Chemistry, a leading chemistry community. The document provides a list of articles and their authors, along with images and permissions. [Extracted from the article]

The document is a contents list for the journal "Dalton Transactions: An International Journal of Inorganic Chemistry." It includes the titles and authors of various articles published in the journal, covering topics such as the synthesis and reactivity of hydride complexes, sustainable copolymers, and the structure and behavior of various metal complexes. The journal is published by The Royal Society of Chemistry, a leading chemistry community. [Extracted from the article]

In this paper, we report a two-dimensional (2D) Hofmann-type spin-crossover coordination polymer [FeII(o-NTrz)2PtII(CN)4]·H2O (o-NTrz = 4-(o-nitrobenzyl)imino-1,2,4-triazole). Due to the remarkable configurational flexibility of triazole-based ligand, the porous structure of this compound can be reversibly regulated by the loss of guest water molecules as a consequence of rotation of o-NTrz. The 180° reorientation of the o-nitrobenzyl moiety not only induces a response of gate-closing/opening of the porous framework but also significantly modulates the spin transition temperature. The present investigation highlights the potential of Hofmann-type SCO compounds with flexible ligands in exploring unusual physical and chemical phenomena. [ABSTRACT FROM AUTHOR]

The document is a contents list for the journal "Dalton Transactions: An International Journal of Inorganic Chemistry," published by The Royal Society of Chemistry. It includes articles on various topics such as electrode materials for batteries, compound synthesis, and catalytic activity. The first article discusses the preparation of Au-loaded mesoporous In2O3 nanoparticles and their improved ethanol sensing performance. The second article is a correction notice regarding tubular metal organic frameworks formed from the curvature of 2D-honeycombed metal coordination. The document also mentions approved training courses offered by the Royal Society of Chemistry. [Extracted from the article]

A novel water-stable CdII-based metal–organic framework, namely {[Cd(BIBT)(TDC)]·2H2O}n (JXUST-28, BIBT = 4,7-bi(1H-imidazol-1-yl)benzo-[2,1,3]thiadiazole and H2TDC = 2,5-thiophenedicarboxylic acid), was synthesized using a mixed-ligand strategy. Structural analysis demonstrates that JXUST-28 exhibits a two-dimensional layer structure with 4-connected sql topology. Intriguingly, JXUST-28 presents good stability in boiling water (at least 5 days), common organic solvents and aqueous solutions with different pH values of 2–12 (more than 24 hours). Furthermore, fluorescence experiments revealed that JXUST-28 could sense Hg2+ ions in aqueous solution via a quenching effect with a detection limit of 0.097 μM. Meanwhile, JXUST-28 can also be regenerated at least 5 times to detect Hg2+ ions. In addition, light-emitting diode lamps, luminescent films, and test papers of JXUST-28 have been successfully developed for practical applications. [ABSTRACT FROM AUTHOR]

Polar cyano fragments and their isomeric isocyano counterparts have attracted great attention as stimuli-responsive luminescent materials in a wide range of fields including organic light-emitting diode devices, chemical fluorescent sensors, photoelectric semiconductors, anti-counterfeit products, etc., mainly because of their typical electron-deficient activity, noncovalent recognition ability, and variable coordination capacity. The electron-deficient and polar nature of these blocks have significant effects on the properties of the cyano/isocyano-based luminophore materials, especially concerning their condensed state-dependent electronic structures. Among them, donor–acceptor (D–A) derived unimolecular and co-assembled luminophores have attracted more attention because their large delocalized structures and noncovalent interaction recognition sites can rebuild the electronic transfer character in the aggregative state, thus endowing them with outstanding stimuli-responsive luminescent behavior via intermolecular and intramolecular charge transfer in polytropic morphologies. In this perspective paper, we give a brief introduction on stimuli-responsive organic and coordinated luminophores and the documented typical design concepts and applications in recent years. It is expected that this perspective article will not only summarize the recent developments of polar cyano/isocyano-derived luminophores and their coordination compounds via structural tailoring and self-assembly but also throw light on the future of the design of more sophisticated stimuli-responsive architectures and their versatile properties. [ABSTRACT FROM AUTHOR]

Developing high-accuracy luminescent sensors for detecting emerging environmental pollutants is of great importance and is still a challenge. Utilizing a 4-carboxyphenylphosphonic acid (H3pbc) ligand, a novel one-dimensional (1D) Zn-based coordination polymer with the formula [Zn2(Hpbc)2(2,2′-bipy)(H2O)]·H2O (Zn–CP, H3pbc = 4-HOOCC6H4PO3H2, 2,2′-bipy = 2,2′-bipyridine) has been hydrothermally synthesized. Each of the 1D chains was linked via π–π stacking interactions and formed a supramolecular framework. Furthermore, due to the existence of uncoordinated –COOH groups, the terbium-functionalized hybrid (Tb3+@Zn-CP) was prepared by introducing Tb3+ ions into the structure through coordinated postsynthetic modification (PSM). Tb3+@Zn-CP shows the characteristic emission of Tb3+ ions due to the "antenna effect" of the H3pbc ligand. Based on the excellent luminescence properties and structural stabilities of Zn-CP and Tb3+@Zn-CP, they can be used as highly sensitive and selective luminescent probes of the UV filter BP (benzophenone) depending on multiquenching effects. In addition, their obvious color change can be easily distinguished by the naked eye under ultraviolet light, which was successfully used in the preparation of portable BP test paper. More importantly, Tb3+@Zn-CP is the first example of CPs as a ratiometric luminescent sensor for BP. This work provides a novel strategy for the construction of ratiometric luminescent probes of BP-type UVFs through coordinated postsynthetic modification. [ABSTRACT FROM AUTHOR]

In the current paper, we have successfully synthesized three new mercury coordination polymers with fascinating structures and properties via a flexible sulfur donor ligand, namely, {[Hg(μ2-Cl)(μ2-Ls)]} n [BF4] n (1), {[Hg(μ2-Cl)(μ2-Ls)]} n [ClO4] n (2), and [Hg(SCN)2(μ2-Ls)] n (3) [Ls = 1,1-bis(3-methyl-4-imidazoline-2-thione)methane]. These complexes have been characterized by means of different techniques such as single crystal X-ray crystallography, FT-IR, elemental analysis (CHNS), UV-Vis, PXRD, BET, and TGA. Suitable single crystals of all complexes were obtained using the branch tube method with a very high yield and good stability due to the high affinity of mercury to bind to the thione groups. The cationic moieties of polymers 1 and 2 were isostructural, with a HgCl2S2 coordination core structure. The voids of the quasi-hexagonal packing of the columnar chains were occupied by unbonded tetrahedral BF4− ions in 1 and perchlorate anions in polymer 2. Polymer 3 has a less distorted tetrahedral geometry than 1 and 2, with a HgS4 core structure. By considering the thiophilicity of mercury, a thioamide-based Ls ligand was used to detoxify Hg(II) into insoluble polymers 1–3. The results of an MTT assay for (HepG2) liver cells confirmed the excellent cytoprotective effect of this ligand against mercury. Based on IC50 calculations, their toxicity was in order of polymer 1 > polymer 2 > polymer 3. These polymers were also considered as adsorbents for the reversible removal of iodine from solution and the kinetics of the process has been studied in detail. Interestingly, all of them showed an excellent stability and high capacity, in order of 763.53 mg g−1, 877.10 mg g−1, and 905.31 mg g−1 for polymers 1–3, respectively. [ABSTRACT FROM AUTHOR]

Automobile exhaust gases, plastic pollutants, smoking, and other harmful substances can cause serious harm to human beings and the environment. Styrene, as a common airborne toxin, enters the human body through breathing or the skin and is discharged in the form of phenylglyoxylic acid (PGA). Therefore, specific, sensitive and trace detection of PGA is particularly important. Here, two zinc-based metal–organic frameworks {[Zn2L1(DMF)2H2O](DMF)2H2O}n, {[Zn4(L2)2(DMF)2(H2O)3](DMF)8}n (L1 = 2,5-bis((3-carboxylphenyl)amino)terephthalic acid, L2 = 2,5-bis((4-carboxyphenyl)amino)terephthalic acid) have been reported as 1 and 2, respectively. Both 1 and 2 present 3D structures, which can both be simplified as 4,4,4-c net topology. It is worth mentioning that 2 has two different kinds of Zn SBUs as connecting nodes in the structure. Besides, compared with the other materials for the detection of PGA, 1 and 2 exhibit relatively low detection limits (LODs), both in water and in urine (where the LODs for 1 in water and urine were 0.33 μM and 0.43 μM in the range of 0–0.39 mM, and those for 2 were 0.28 μM and 0.49 μM in the range of 0–0.59 mM, respectively). In addition, the sensors have excellent anti-interference ability, high stability, rapid response, and can easily distinguish between different concentrations of PGA with the naked eye. The developed paper probes were suitable for practical sensing applications for portable detection of PGA in urine. [ABSTRACT FROM AUTHOR]

Two complexes {[GdCu5(GlyHA)5(H2O)7Cr(C2O4)3]·11.02H2O}n (1) and {{[GdCu5(GlyHA)5(H2O)6]μ2-[Cu(C2O4)2(H2O)]}2μ4-[Cu(C2O4)2]·15.8H2O}n (2), were obtained as outcomes of the reactions between the cationic hexanuclear {GdCu5(GlyHA)5}3+ 15-metallacrown-5 complex (where GlyHA2− = glycinehydroxamate) and the anionic oxalate complexes K3[Cr(C2O4)3] or K2[Cu(C2O4)2]. Both 1 and 2 possess polymeric 1D-chain structures according to X-ray structural analysis. As a consequence of the geometric orientations of the donor atoms in the oxalates from [Cr(C2O4)3]3−, the Cu5 mean planes of neighboring 15-metallacrown-5 units {GdCu5(GlyHA)5}3+ are angled at 75.5° to each other, which leads to formation of a zig-zag motif in the 1D-chains of complex 1. The centrosymmetric complex 2 contains two structurally different bis(oxalato)cuprate anions μ2-[Cu(C2O4)2(H2O)]2−, for one of which, coordination to two adjacent {GdCu5(GlyHA)5}3+ units leads to formation of linear 1D-chains in 2, while the second type, μ4-[Cu(C2O4)2]2−, is coordinated to four {GdCu5(GlyHA)5}3+ units, causing the cross-linking of single 1D-chains into a double-chain 1D coordination polymer. Studies of χMT vs. T data for 1 and 2 in a 2–300 K temperature range revealed the presence of both ferromagnetic and antiferromagnetic interactions amongst paramagnetic centres. The experimental χMT vs. T data for 1 were fitted using a model which takes into account exchange interactions between adjacent copper(II) ions, the Gd–Cu exchange interactions within {GdCu5(GlyHA)5}3+ units and additionally Gd–Cr exchange interactions. Fitting of the χMT vs. T data for 2 was not possible, since coordination of μ4-[Cu(C2O4)2]2− to {GdCu5(GlyHA)5}3+ led to the non-equivalence of several Cu–Cu exchange interactions within the metallacrown units and hence a superfluity of fittable parameters. Complexes 1 and 2 are the first examples of 15-metallacrown-5 complexes demonstrating a magnetocaloric effect (−ΔSM at 13 T reaches 24.26 J K−1 kg−1 at 5 K and 19.14 J K−1 kg−1 at 4 K for 1 and 2, respectively). [ABSTRACT FROM AUTHOR]

Lanthanide clusters with high magnetic entropy and an exquisite structure have always been a hot research direction. Herein, two delicately structured lanthanide clusters were synthesized using isonicotinic acid (HIN) as a ligand by the solvothermal method, namely {[Gd4(IN)4(μ3-OH)4(OAc)2(H2O)6]·Cl2·7H2O}n (1) and {[Dy4(IN)4(μ3-OH)4(OAc)2(H2O)6]·Cl2·8H2O}n (2). Structural analysis indicates that the two compounds exhibit comparable structures, and both have the same cubane-like Ln4 metal skeleton and form an interesting dragonfly molecular configuration by connecting to HIN. Moreover, {Ln4} serves as the fundamental structural unit for the construction of a 1D channel of 1, with a diameter of approximately 10.08 Å, which is connected to each other by extra {Ln4} units to form an exquisite porous 3D structure of 1. Cl− exists as an anion-template in its 3D structure, balancing the charge and maintaining its structural stability. Magnetic measurements indicate that 1 exhibits a rather satisfactory magnetic entropy change, reaching a maximum value of −ΔS maxm = 31.59 J kg−1 K−1 at 2 K for ΔH = 7 T. [ABSTRACT FROM AUTHOR]

A new cyanido bridged Zn(II)–Mn(II) mixed-metal coordination polymer, {[Zn(μ-L)(μ-CN)2Mn0.5]·(CH3OH)}n (1), has been synthesized by the reaction of Zn(CN)2, Mn(II) salts and a hydrazone ligand (HL = (E)-N′-(phenyl(pyridin-2-yl)methylene)isonicotinohydrazide) in methanol. Compound 1 was characterized using various analytical methods (including elemental analysis, photoluminescence, FT-IR, XRD, SEM, and EDX analyses, and TGA), and its structure was determined by X-ray analysis. These analyses confirmed the formation of a mixed metal Zn(II)–Mn(II) coordination polymer containing both cyanide and hydrazone bridging ligands. This mixed metal coordination polymer exhibits interesting emission spectra by having several emissions via excitation at 230, 270, 375 and 385 nm. The catalytic activity of compound 1 in chemical CO2 fixation was investigated in the presence of epoxides, and the effects of various parameters on its catalytic performance were evaluated. The results of catalytic studies show that compound 1 can efficiently catalyze the chemical CO2 fixation reaction under mild conditions. The amount of co-catalyst, temperature of the reaction, nature of the solvent and also the substituent connected to the epoxide ring are some of the important parameters that have considerable effects on the catalytic activity of 1. [ABSTRACT FROM AUTHOR]

Developing and investigating advanced multifunctional materials with magnetic properties as candidates for assembling spin qubits for quantum computing is imperative. A new polytopic ligand based on oxamate and aniline was used to promote the synthesis of three neutral homometallic lanthanide-coordinated polymers. New complexes with the formula {Ln(phox)3(DMSO)2(H2O)}n, where Ln = Eu3+ (1), Gd3+ (2), and Tb3+ (3) [phox = N-(phenyl)oxamate and DMSO = dimethylsulfoxide], were synthesized and well characterized by spectroscopic methods as well as X-ray crystallographic analysis. All crystalline structures comprise neutral zigzag chains. The lanthanide ions are linked by three phox ligands, in which two oxygen atoms from two different ligands are responsible for connecting the trivalent lanthanide ions, and one phox ligand completes the coordination sphere in a bis-bidentate mode, together with two DMSO molecules and one water coordination molecule. The coordination sphere of lanthanide ions consisted of spherical capped square antiprism (CSAPR-9) symmetry. The magnetic properties of 1–3 were investigated in the 2–300 K temperature range. The dynamic (ac) magnetic properties of 2 reveal a frequency dependence involving the phonon bottleneck mechanism below 33 K under nonzero applied dc magnetic fields, resulting in an example of a field-induced single-molecule magnet. Solid-state photophysical measurements for Eu3+ (1) and Tb3+ (3) complexes indicate that the N-(phenyl)oxamate ligands are very efficient in sensitizing the lanthanide(III) ions in the visible region of the electromagnetic spectrum. Compounds 1 and 3 exhibited an emission in the red and green regions, respectively. Experimental results and theoretical calculations using the Sparkle/RM1 method support a quantum efficiency of ∼72% for 1, suggesting its potential as a candidate for light conversion molecular devices (LCMDs). [ABSTRACT FROM AUTHOR]

Two bidentate ligands (L1 = 1-pentyl-2-(pyridin-2-yl)-1H-benzimidazole and L2 = 1-heptyl-2-(pyridin-2-yl)-1H-benzimidazole) were employed for the synthesis of five mononuclear Fe(II) coordination compounds 1–5 containing perchlorate, tetrafluoroborate and triflate counterions. Single-crystal X-ray diffraction analysis confirmed the expected molecular structures of all the reported compounds, revealing a moderately distorted octahedral geometry of {FeN6} coordination chromophores. All five compounds exhibit thermal spin crossover with T1/2 temperatures allocated above 400 K. The theoretical calculations supported the experimental magnetic investigation and helped to explain the electronic structures of the reported complexes with respect to the occurrence of thermal spin state switching. In addition, compound 4 was employed for the preparation of Langmuir–Blodgett films and fabrication of molecular films using the method of spontaneous evaporation of the subphase. While the formation of Langmuir–Blodgett films was unsuccessful due to the instability of the compound at the water/air interface, the latter technique allowed the formation of molecular films of 4 with well-defined thickness and homogeneity. [ABSTRACT FROM AUTHOR]

The 1D homochiral coordination polymer (CP-1) {[Co(dTMP)(bpe)2(H2O)3]·9H2O}n was constructed by using 2′-deoxy thymidine 5′-monophosphate disodium salt (dTMP·2Na), and auxiliary ligand bpe (1,2-bis(4-pyridyl)ethene) and characterized by single-crystal XRD, PXRD, IR, UV-visible, CD and TGA analyses. Molecular simulations revealed the selective chiral behaviour of CP-1 towards phenylalanine and histidine, as indicated by their higher binding free energies compared to other amino acids. Theoretical parameters were also compared with experimental UV-visible verdicts. Notably, the D -enantiomers of phenylalanine and histidine demonstrated strong bonding abilities and optimal configurations for probing and distinguishing them from their L -counterparts. These findings led to propositions suggesting that the dissimilarities between these D and L amino acid forms and their binding orientations with CP-1 may contribute to alterations in the CD signal. CP-1 exhibited a robust inherent circular dichroism (CD) signal in aqueous solutions, modulated by the presence of specific amino acids, namely D / L phenylalanine and D / L histidine. Leveraging the measurement of CD signal intensity, a sensor capable of detecting unmodified amino acids has been developed. Unlike previously reported approaches that relied on complex chemical reactions between initially CD-silent molecules and probed amino acids, this new method offers a more straightforward means of amplifying the CD signal. Consequently, this change facilitates a more accurate differentiation between the enantiomers of these specific amino acids compared to others. [ABSTRACT FROM AUTHOR]

Eugenol, the major constituent of clove oil, has been explored as an essential natural ingredient for ages owing to its versatile pharmacological properties. However, to date, the coordination chemistry of eugenol derivatives has not been much explored. In the present work, an eugenol-based Schiff base ligand (HL) was synthesized and structurally confirmed through ESI-MS, NMR, and FT-IR spectroscopy studies. Consequently, the N,O-donor chelating ligand HL was coordinated with Cd2+, in the presence of bridging pseudohalides (thiocyanate, SCN−, and dicyanamide, N(CN)2−) to synthesize two luminescent coordination polymers (CPs 1 and 2): [Cd2(L)2(X)2]n (where HL = 4-allyl-2-(((2-(benzylamino)ethyl) imino)methyl)-6-methoxyphenol and Xs are bridging pseudohalides, i.e., SCN− and N(CN)2−) on a Cd-eugenol scaffold. The CPs depicted structural diversity, bulk-phase purity, thermal stability, and the presence of interlayer supramolecular C–H⋯π interactions together with C–H⋯S (for CP 1) and C–H⋯N (for CP 2) interactions. The CPs further exemplified themselves as selective and sensitive 'turn-off' probes towards trinitrophenol (TNP) (quenching efficiency: 82.02% and 83.86% for 1 and 2) among a pool of hazardous nitroaromatic compounds (NACs). Accordingly, 1 and 2 exhibited an ultralow limit of detection (LOD) of 0.29 and 0.15 μM, with high quenching constants (KSV) of 5.91 × 104 and 17.60 × 104 M−1, respectively. In addition, TNP sensing events were evidenced to be recyclable and exhibited fast response (∼31 s, 1, and ∼40 s, 2), which increased its real-world viability. Vapor phase TNP sensing was also accomplished upon drop-casted CP films. Experimental investigations and theoretical DFT study confirmed the cooperative occurrence of RET-IFE-PET-collisional quenching and non-covalent π⋯π stacking as key factors involved in the TNP sensing performance. The competency of 1 and 2 in the detection of TNP from several complex environmental matrices (CEMs), viz. matchstick powder, river and sewage water, and soil specimens, was also established with good recovery (∼66–86% and ∼68–93% for 1 and 2, respectively) and high KSV values (3.90–11.39 × 104 and 6.17–18.79 × 104 M−1 for 1 and 2, respectively). [ABSTRACT FROM AUTHOR]

Although organometallic porous polymer networks are recognized as promising heterogeneous catalysts, the relationship between ligand/monomer geometry and network parameters is usually not well understood due to the lack of atom-resolved characterization methods for the amorphous network matrix. In this work, a series of copper(II) salen-type metal complexes was synthesized, using trans- and cis-1,2-diaminocyclohexane segments, and thoroughly characterized by single-crystal X-ray diffraction and solution- and solid-state NMR spectroscopy. Terminal ethynyl groups of the complexes were then transformed into polyacetylene chains by coordination chain-growth homopolymerization, resulting in highly porous (458–655 m2 g−1) organometallic polymer networks with a copper(II) ion content of about 12 wt%. The presence of paramagnetic copper(II) moieties in these complexes and respective polymer networks required the application of tailored NMR techniques, which together with X-ray crystallography and DFT calculations of the paramagnetic NMR shifts made it possible to investigate the differences in the complex geometry in liquid, powder and crystalline form and compare it with the complex geometry in polymer networks. All prepared organometallic polymer networks were also tested as heterogeneous catalysts for styrene oxidation with uncommonly high substrate conversions and compared with their low-molecular-weight analogues. The high reusability of such heterogeneous polymer-based catalysts was also proven. [ABSTRACT FROM AUTHOR]

Porous molecular crystals (PMCs) have gained significant importance as next-generation functional porous materials. However, the selective crystallisation of the PMC phase remains a challenge. Herein, we have systematically controlled the stability of the luminescent PMC phase prepared using the luminescent Pt(II) complex [Pt(pbim)(N^O)] (pbim = 2-phenylbenzimidazolate, N^O = N-heteroaryl carboxylate) with Pt⋯Pt electronic interactions. The PMC phase formation varied significantly among the complexes depending on the heteroaryl group of the ancillary N^O ligand; the oxazolyl-bearing complex did not form a PMC phase, whereas the pyrazyl- and 5-fluoropyridyl-bearing complexes spontaneously formed a porous structure. This difference was rationalised by the π-stacking capability of the heteroaryl group of the ancillary ligand. Furthermore, owing to the presence of the one-dimensional Pt⋯Pt chains in this PMC phase, the photophysical properties of PMCs resulting from the Pt⋯Pt interactions were also significantly changed by the ancillary ligands. [ABSTRACT FROM AUTHOR]

Thermal expansion regulation by chemical decoration at a molecular level is of great technological value for materials science. Herein, we show that the spin crossover active compound Fe(pyz)Pt(CN)4 (pyz = pyrazine) shows a rare 2D negative thermal expansion (NTE) in the ab-plane. By introducing axial coordination iodine ions or reducing the framework dimension from 3D to 2D, the NTE behavior can be effectively switched to positive thermal expansion (PTE) or even zero thermal expansion (ZTE). Moreover, it is found that different spin states of Fe2+ also influence the magnitude of NTE. Compared with the low-spin (LS) sate, the high-spin (HS) state tends to enhance the magnitude of NTE. Combined in situ structural and Raman spectral analyses revealed that the NTE mainly originates from the transverse vibration of a bridging cyano group and the tailorable thermal expansion is closely related to the state of the Fe–C≡N–Pt linkage. The present study shows how the rational regulation of the building unit and framework dimensions can effectively control thermal expansion behaviors. This insight can serve as guidance for designing and synthesizing novel NTE materials. [ABSTRACT FROM AUTHOR]

The syntheses, structures, luminescence and magnetic properties of a new series of Ln(III) complexes of the formula [Ln(L)(H2O)2(DMF)2][Ln(L)2] (in which H2L is N,N′-ethylaminebis[1-phenyl-3-methyl-4-formylimino-2-pyrazoline-5-one]; Ln(III) – Gd (1), Tb (2), or Dy (3) ions). The crystal structures were determined by single-crystal X-ray diffraction measurements for all the above-mentioned complexes. The crystals of these compounds consist of cationic [Ln(L)(H2O)2(DMF)2]+ and anionic [Ln(L)2] moieties which form a 3D supramolecular architecture by the H-bonds and electrostatic forces. Luminescence emission in the visible range was observed for Tb(III) and Dy(III) compounds upon ligand sensitization, with moderate quantum yields of 3.2% for the Dy complex and 24.2% for the Tb analogue. Moreover the Tb(III) complex demonstrates triboluminescence activity. The dynamic magnetization studies revealed that 1 and 2 demonstrate field-induced magnetic relaxation with effective energy barriers, ΔE‖kB = 24 K (for 1) and 85 K (for 2), while the Dy complex 3 exhibits slow relaxation of magnetization in zero field with an activation energy of 256 K. [ABSTRACT FROM AUTHOR]

An in situ hydrolysis of the P–Cl bonds of the carbophosphazene [{NC(NMe2)}2{NPCl2}] (LPCl2) in the presence of hydrated lanthanide(III) nitrates in a dichloromethane and methanol (2 : 1) solvent mixture afforded a series of novel 1D coordination polymers: [{Ln(LHPO2)3(NO3)2(CH3OH)(H2O)} (Cl)]n {where Ln(III) = Gd (1), Tb (2), Dy (3), or Er (4) and LHPO2 is the hydrolyzed carbophosphazene (LPCl2) ligand}. X-ray crystallographic analysis revealed that complexes 1–4 are isostructural and crystallized in the monoclinic crystal system having P21/c space group. The coordination polymers are formed because of the involvement of the geminal P(O)(OH) moieties of the carbophosphazene ligand. Each lanthanide(III) ion is 9-coordinate (9O) in a distorted muffin geometry. Magnetic measurements revealed that both DyIII and ErIII analogues exhibit field-induced single-molecule magnet (SMM) behavior at 0.8 kOe and 2.2 k Oe, respectively. At such dc fields, the dynamic magnetic susceptibility displays complex behavior with a triple magnetic relaxation contribution for 3, while two contributions were identified for 4. The observed static and dynamic magnetic behavior for complexes 1–4 were further rationalized with the aid of BS-DFT and CASSCF/SO-RASSI/SINGLE_ANISO calculations. [ABSTRACT FROM AUTHOR]

A thiophene-derived Schiff base ligand (E)-2-morpholino-N-(thiophen-2-ylmethylene)ethanamine was used for the synthesis of M(II) complexes, [TEM(M)X2] (M = Co, Cu, Zn; X = Cl; M = Cd, X = Br). Structural characterization of the synthesized complexes revealed distorted tetrahedral geometry around the M(II) center. In vitro investigation of the synthesized ligand and its M(II) complexes showed considerable anti-urease and leishmanicidal potential. The synthesized complexes also exhibited a significant inhibitory effect on urease, with IC50 values in the range of 3.50–8.05 μM. In addition, the docking results were consistent with the experimental results. A preliminary study of human colorectal cancer (HCT), hepatic cancer (HepG2), and breast cancer (MCF-7) cell lines showed marked anticancer activities of these complexes. [ABSTRACT FROM AUTHOR]

In this study, three different solvent systems have been employed to investigate the effect of reaction parameters on the synthesis of four alkaline earth metal-based MOFs namely [Ca(0.5 1,4-phenyl diacetic acid)2(H2O)DMF]∞ (Ca-MOF-1), [Ca(1,4-naphthalene dicarboxylate)DMF]∞ (Ca-MOF-2), [Ca2(0.5 1,2,4,5-benzene tetracarboxylate)2(H2O)3DMF]∞ (Ca-MOF-3) and [Ca2(2,6-naphthalene dicarboxylate)2(H2O)6]∞ (Ca-MOF-4). The crystal structures of these four MOFs have been resolved through single crystal X-ray analysis and the bulk phase purity of these MOFs was assessed using PXRD and FT-IR analysis. To check the stability of these MOFs, thermogravimetric analysis (TGA) was carried out. To analyze the robustness of these MOFs, the PXRD of the samples was also collected at different pH levels. These MOFs were further explored as Lewis acid catalysts for the alcoholysis of epoxides and the activity of these catalysts depend on the open metal sites present in the MOFs. The catalytic activity follows the order: Ca-MOF-2 > Ca-MOF-4 > Ca-MOF-1 > Ca-MOF-3. The activity was also checked with various epoxide substrates using Ca-MOF-2. Density functional theory (DFT) calculations also support this trend with the help of the thermodynamic feasibility of epoxide binding, considering model MOF structures. The weak interaction between the epoxide oxygen and the metal centre of the most stable MOF structure has also been clarified by computational studies. [ABSTRACT FROM AUTHOR]

A series of four Cd(II) complexes with 5-methyl-4-imidazolecarboxaldehyde (L) with different inorganic anions within or outside the coordination sphere of general formula: [CdCl2L2] (1), [CdBr2L2] (2), [CdI2L2] (3), and [CdL4](PF6)2·3H2O (4) was synthesized through one-step and two-step reactions, respectively. All complexes were obtained as colorless crystals without the need for recrystallization and exhibited solubility in aqueous solutions. Structural analysis revealed different coordination environments for each complex, with variations in bond lengths and angles. The crystal packing of the complexes was stabilized by hydrogen bonding and π–π stacking interactions. FT-IR analysis indicated coordination of the ligand to the metal ion, and UV-Vis studies confirmed the stability of the complexes in solution. Computational analysis has revealed the polar nature of the complexes and their favorable stability constants. Affinity studies with DNA using the switchSense technique demonstrated rapid association and dissociation processes for all complexes, with temperature-dependent binding constants. Thermodynamic analysis suggested spontaneous with positive entropy change and endothermic formation processes for the complexes. Overall, the study underscores the synthesis, examination, and interaction with DNA of Cd(II) complexes, demonstrating their promise within medicinal chemistry. [ABSTRACT FROM AUTHOR]

A new doubly carboxylato-bridged Co(II) dinuclear complex, [Co(bdtbpza)(NCS)]2 (1), was obtained in a satisfactory yield by employing a 'scorpionate'-type precursor, bdtbpza {bis-(3,5-di-tert-butylpyrazol-1-yl)acetate}, and was then structurally characterized. Single-crystal X-ray diffraction analysis revealed that, in 1, each Co(II) is penta-coordinated, leading to a distorted trigonal–bipyramidal geometry within the coordination environment of N3O2. Weak antiferromagnetic coupling within the Co(II) ions in 1 was found based on the isotropic spin Hamiltonian H = −J(S1·S2) for the Si = 3/2 system. For evaluating the spin density distribution and the mechanism for the magnetic exchange coupling, DFT analysis was performed, with the calculated result agreeing the experimental magnetic data. A study into electrochemical H2 evolution, involving cyclic voltammetry (CV), controlled potential electrolysis (CPE), and gas chromatographic (GC) analyses of the graphite electrode modified with the cobalt complex in a neutral aqueous solution revealed the high catalytic activity of the complex with a low overpotential toward H2O reduction. The faradaic efficiency of the catalyst was found to be 83.7% and the di-cobalt catalyst-modified electrode displayed quite an interesting H2-evolution activity compared with that of bare electrodes. These results are encouraging for the future potential application of 1 in water splitting. [ABSTRACT FROM AUTHOR]

Zinc(II)-complexes with the general formula [Zn(L)2] containing 8-hydroxyquinoline Schiff bases functionalized with 1-(3-aminopropyl)imidazole or 1-(3-aminopropyl)-2-methyl-1H-imidazole on 2-position and their respective ligands (HL1 or HL2) were synthesized and characterized by NMR, UV-Vis, FTIR and CD spectroscopies as well as ESI-MS spectrometry. Single crystals of HL2 and [Zn(L1)2]n were analysed by SC-XRD. [Zn(L1)2]n shows a 1D polymeric chain structure of alternating Zn(II) cations and bridging Schiff base ligands, in contrast to previously reported monomeric structures of analogous complexes. DFT calculations were performed to rationalize the polymeric X-ray structure of Zn(L1)2. Results showed that the ligands can bind as bi- or tridentate to Zn(II) and there is the possibility of a dynamic behavior for the complexes in solution. Both ligands and complexes present limited stability in aqueous media, however, in the presence of bovine serum albumin the complexes are stable. Molecular docking simulations and circular dichroism spectroscopic studies suggest binding to this protein in close proximity to the Trp213 residue. Biological studies on a panel of cancer cells revealed that the Zn(II)-complexes have a lower impact on cell viability than cisplatin, except for triple-negative breast cancer cells in which they were comparable. Notwithstanding, they display much higher selectivity towards cancer cells vs. normal cells, than cisplatin. They induce the generation of ROS and DNA double-strand breaks, primarily through apoptosis as the mode of cell death. Overall, the novel Zn(II)-complexes demonstrate improved induction of apoptosis and higher selectivity, particularly for melanoma cells, compared to previously reported analogues, making them promising candidates for clinical application. [ABSTRACT FROM AUTHOR]

Two new cyanido-bridged {FeIIMII} double chains were obtained by reacting cyanido anions [M(CN)4]2- with complex cations [FeII(tptz)]2+ (preformed in situ by mixing a hydrated tetrafluoroborate salt of iron(II) and a tptz ligand, tptz = 2,4,6-tri(2-pyridyl)-1,3,5-triazine) having the general formula [FeII(tptz) MII(CN)4]·2H2O·CH3CN, where M = Pd (1) or Pt (2). Additionally, two molecular complexes formulated as [FeII(tptz)2][MII(CN)4]·4.25H2O, where M = Pd (3) or Pt (4), were subsequently obtained from the same reaction, as secondary products. Single crystal X-ray analysis revealed that 1 and 2 are isostructural and crystallize in the P-1 triclinic space group. Their structure consists of a double-chain with a ladder-like topology, in which cyanido-based [M(CN)4]2- metalloligands coordinate, through three CN- ligands and three [FeII(tptz)]2+ complex cations. Compounds 3 and 4 are also isostructural and crystallize in the P1¯ triclinic space group, and the X-ray structural data show the formation of [FeII(tptz)2]2+ and [MII(CN)4]2- ionic units interconnected through H-bonds and π⋯π stacking supramolecular interactions. The static DC magnetic measurements recorded in the temperature range of 2-300 K showed that 1 and 2 exhibit incomplete spin transition on cooling, which is also confirmed by single crystal XRD analysis and Mössbauer spectroscopy. Compounds 3 and 4 are diamagnetic, most likely due to the encapsulation of Fe(II) in a tight pocket formed by two tptz ligands that preserve the low-spin state in the temperature range of 2-400 K. [ABSTRACT FROM AUTHOR]

Metal-organic cages (MOCs) are an emerging class of porous materials with promising applications. However, controlling the configuration of the cage packing, which can influence the overall porosity of the materials, remains a difficulty, as many factors can influence the cage assembly and stacking. Herein, we report a solvent strategy to fine-tune the packing configuration of a bilayer MOC, a small triangular prism cage (six Cu ions act as vertices, three nitrate ions act as pillars, and six nitrate ions act as caps) incorporated into a large triangular prism cage (another six Cu ions act as vertices, a couple of oxygen atoms act as pillars and six ligands (L1: 3,5-bis(pyridine-3-yl)-4H-1,2,4-triazole) act as a jointed cap) by the coordination between the triazole nitrogen from L1 and the inner vertex Cu ions. The involved solvents water, acetonitrile (MeCN) and N,N'-dimethylformamide (DMF) form hydrogen bonds with this bilayer MOC, resulting in three different types of packing associated with systemically tuned porosity (NTU-93: 12.2%, NTU-94: 19.3%, and NTU-95: 42.1%). Gas adsorption and breakthrough tests demonstrate that NTU-95 has potential ability for C2H2/C2H4 separation. This work not only shows a case of finely tuned packing of coordination cages, but also provides a powerful tool that may be extended to other cage families. [ABSTRACT FROM AUTHOR]

Two photochromic Cd(II)-CPs were obtained based on the viologen ligand using different synthetic routes, named {[Cd4(p-BDC)4(CPB)2(H2O)2]·2H2O·EtOH}n (1) and {[Cd(p-BDC)(CPB)(H2O)]·(L)·DMF}n (2) (p-H2BDC = 1,4-benzene-dicarboxylate, HCPB·Cl = 1-(4-carboxyphenyl)-4,4′-bipyridinium·Cl, L = 2,4-dinitrochlorobenzene, and DMF = N,N-dimethylformamide), respectively. Due to different coordination modes, the two Cd(II)-CPs show different structures. Compound 1 exhibits a three-dimensional (3D) framework with bimetallic nodes, while compound 2 displays a 2-fold interpenetrated (4,4) net topology. Notably, the two Cd(II)-CPs exhibit substantial disparities in photo/thermochromism, which can be attributed to variations in donor–acceptor (D–A) distances arising from structural differences. Compound 1 showed visually sensitive photo- and thermochromic behavior due to multi-pathway electron transfer and short D–A distances, which is relatively rare in electron-transfer type photochromic systems. In contrast, 2 only demonstrates insensitive photochromic behavior, with a slight deepening of the color observed after 2 hours of UV light, which is due to the mono-pathway electron transfer and long D–A distance. Moreover, we first combined Cd(II)-viologen CPs with polydimethylsiloxane (PDMS) to prepare a 1@PDMS flexible UV imaging film. 1@PDMS exhibits excellent bendability and stretchability and maintains good photochromic properties after 100 bending cycles. To demonstrate the rapid color response and distinct color contrast of 1, its application in anti-counterfeiting is also demonstrated. [ABSTRACT FROM AUTHOR]

Developing high performance noble-metal-free electrocatalysts as an alternative to Pt-based catalysts for the oxygen reduction reaction (ORR) in energy conversion devices is highly desirable. We report herein the preparation of a coordination-polymer (CP)-derived Fe/CP/C composite as an electrocatalyst for the ORR with excellent activity and stability both in solution and in Zn-air batteries. The Fe/CP/C catalyst was obtained from the pyrolysis of an iron porphyrin Fe(TPP)Cl (5,10,15,20-tetraphenyl-21H, 23H-porphyrin iron(III) chloride) grafted Zn-coordination polymer with dangling functional groups 4,4'-oxybisbenzoic acid and 4,4'-bipyridine ligands. The Fe/CP/C catalyst showed much higher ORR activity with a half-wave potential (E1/2) of 0.90 V (vs. RHE) than the Fe/C catalyst (E1/2 = 0.85 V) derived from the carbon-blacksupported Fe porphyrins in 0.1 M KOH solution. When Fe/CP/C was used as the cathode electrocatalyst in Zn-air batteries (ZABs), the ZABs achieved a significantly higher open circuit voltage (OCV = 1.43 V) and maximum power density (Pmax = 142.8 mW cm-2) compared with Fe/C (OCV = 1.38 V, Pmax = 104.5 mW cm-2) and commercial 20 wt% Pt/C (OCV = 1.41 V, Pmax = 117.6 mW cm-2). Using dangling functional groups in CP to increase the loading efficiency of iron porphyrins offered a facile method to prepare high-performance noble-metal-free electrocatalysts for the ORR, which may provide promising applications to energy conversion devices. [ABSTRACT FROM AUTHOR]

A novel series of one-dimensional coordination polymers (CPs) is achieved via a facile one-pot synthesis strategy employing the nitrate salts of trivalent lanthanides, a pentadentate chelating ligand, and triphenylphosphine oxide at a controlled stoichiometry under ambient conditions. All the CPs are characterized comprehensively using spectroscopic, X-ray crystallographic and magnetometric studies. The CPs are found to be thermally stable up to a significantly high temperature and resistant to water for an indefinite time. They are photoactive and exhibit selective fluoride ion (F-) sensing with excellent efficiency both colorimetrically and fluorimetrically in the solid-state as well as in solution. The presence of F- concomitantly sensitizes the photoluminescence enhancement and visual decolourization of the CPs in solution owing to the ground-state intra-molecular proton transfer. The photophysical response of the CPs to F- in solution was found to be instantaneous (<30 s). The sensitivity of detection is observed to be significantly high over a wide range of F- concentrations, covering the beneficial and detrimental domains of F- concentrations in drinking water. The limit of detection (LoD) under ambient conditions was found to be in the micromolar (µM) range--the best being 0.22 µM found using UV-vis spectrometry and 7.5 µM using fluorimetry. In comparison, the USEPA standard cut-off for the upper limit of F- concentration in drinking water is 211 µM, and the LoD of measuring F- concentration using the USEPA standard method using a fluoride-selective electrode is 26.3 µM. The CPs display markedly high selectivity toward F- with negligible-to-no interference from the commonly abundant ions (Cl-, Br-, I-, CH3CO2-, CO32-, SO42-,HPO42-, NH4+, Na+, K+, Mg2+, and Ca2+) in terms of UV-vis spectral change. Moreover, they also exhibit solid-state IR-spectrometric sensitivity towards F- under ambient conditions. [ABSTRACT FROM AUTHOR]

A series of two-dimensional (2D) spin-crossover coordination polymers (SCO-CPs) [FeII(TPE)(NCX)2]·solv (1: X = BH3, solv = H2O·2CH3OH·DMF; 2: X = Se, solv = H2O·2CH3OH·0.5DMF; 3: X = S, solv = H2O·2CH3OH·0.5DMF) were synthesized by employing 1,1,2,2-tetra(pyridin-4-yl)ethene (TPE) and pseudohalide (NCX-) coligands. Magnetic measurements indicated that complexes 1-3 exhibited SCO behaviors with diminishing thermal hysteresis (7/4/0 K) upon decreasing the ligand-field strength. The critical temperatures (Tc) during spin transition were found to be inversely proportional to the coordination ability parameters (a™) with a linear correlation. The guest effect was also investigated in the solvent-exchanged phases 1-SE/2-SE/3-SE wherein the DMF molecules were replaced by methanol molecules. Compared with 1-3, 1-SE/2-SE/3-SE displayed more abrupt and complete single-step SCO behaviors but narrower thermal hysteretic loops. The results reported here demonstrate that the Tc values of these two families were dominated by the ligand-field strength of the NCX- anions (NCBH3 > NCSe > NCS), whereas the guest effect only modulated the kinetic factor of the SCO nature in this system. [ABSTRACT FROM AUTHOR]

The construction of sulfur-incorporated cluster-based coordination polymers was limited and underexplored due to the lack of efficient synthetic routes. Herein, we report facile mechanochemical ways toward a new series of SFe3(CO)9-based dipyridyl-Cu polymers by three-component reactions of [Et4N]2[SFe3(CO)9] ([Et4N]2[1]) and [Cu(MeCN)4][BF4] with conjugated or conjugation-interrupted dipyridyl ligands, 1,2-bis(4-pyridyl)ethylene (bpee), 1,2-bis(4-pyridyl)ethane (bpea), 4,4'-dipyridyl (dpy), or 1,3-bis (4-pyridyl)propane (bpp), respectively. X-ray analysis showed that bpee-containing 2D polymers demonstrated unique SFe3(CO)9 cluster-armed and cluster-one-armed coordination modes via the hypervalent µ5-S atom. These S-Fe-Cu polymers could undergo flexible structural transformations with the change of cluster bonding modes by grinding with stoichiometric amounts of dipyridyls or 1/[Cu(MeCN)4]+. They exhibited semiconducting behaviors with low energy gaps of 1.55-1.79 eV and good electrical conductivities of 3.26 × 10-8-1.48 × 10-6 S cm-1, tuned by the SFe3(CO)9 cluster bonding modes accompanied by secondary interactions in the solid state. The electron transport efficiency of these polymers was further elucidated by solidstate packing, X-ray photoelectron spectroscopy (XPS), X-ray absorption near-edge spectroscopy (XANES), density of states (DOS), and crystal orbital Hamilton population (COHP) analysis. Finally, the solid-state electrochemistry of these polymers demonstrated redox-active behaviors with cathodically-shifted patterns compared to that of [Et4N]2[1], showing that their efficient electron communication was effectively enhanced by introducing 1 and dipyridyls as hybrid ligands into Cu+-containing networks. [ABSTRACT FROM AUTHOR]

Owing to their structural designability and tuneable properties, supramolecular metal–organic complexes have recently emerged as promising candidates for the sensing and detection of molecules and anions. Herein, we synthesised three tripyrazolate-linked [M6L2] metallocages with the formulas [(bpyPd)6L2](NO3)6 (1), [(dmbpyPd)6L2](NO3)6 (2), and [(phenPd)6L2](NO3)6 (3) (H3L = tris(4-(5-(trifluoromethyl)-1H-pyrazol-3-yl)phenyl)amine, bpy = 2,2′-bipyridine, dmbpy = 4,4′-dimethylbipyridine, phen = 1,10-phenanthroline). Crystallography revealed that metal-directed coordination and the bidentate chelate behaviour of the ligand induced the self-assembly of supramolecular metal–organic cages. Notably, these cages were employed as turn-on fluorescence sensors for SO2 and its derivative (HSO3−) through a disassembly mechanism. Cages 1, 2, and 3 showed a highly selective and sensitive detection of HSO3− over other common anions in aqueous solutions and of SO2 gas over other common gasses, with an excellent anti-interference ability. These metallocages were subsequently applied as sensors in environmental and biological samples. This study not only enriches the ongoing research on metal–organic supramolecular materials but also facilitates the future preparation of stimuli-responsive supramolecular coordination complexes. [ABSTRACT FROM AUTHOR]

Hofmann-like cyanometallic complexes represent one of the biggest and well-known classes of FeII spin-crossover compounds. In this paper, we report on the first FeII Hofmann clathrate analogues with unsubstituted 1,2,3-triazole, which exhibit temperature induced spin transition. Two new coordination polymers with the general formula [FeII(1,2,3-triazole)2MII(CN)4] (M = Pt, Pd) undergo abrupt hysteretic spin crossover in the range of 190–225 K as revealed by magnetic susceptibility measurements. Two compounds are isostructural and are built of infinite cyanometallic layers which are supported by 1,2,3-triazole ligands. The thermal hysteresis loop is very stable at different scan rates from 0.5 to 10 K min−1. The compounds display strong thermochromic effect, changing their colour from pink in the low-spin state to white in the high-spin state. Our findings show that 1,2,3-triazole is suitable for elaboration of spin-crossover Hofmann clathrate analogues, and its use instead of more classical azines can advantageously expand this family of complexes. [ABSTRACT FROM AUTHOR]

Reactions between 1,2-di(tetrazol-2-yl)ethane (ebtz), 1,6-di(tetrazol-2-yl)hexane (hbtz) or 1,1′-di(tetrazol-1-yl)methane (1ditz) and Fe(BF4)2 in the presence of adiponitrile (ADN), glutaronitrile (GLN) or suberonitrile (SUN) resulted in the formation of coordination polymers [Fe(μ-ebtz)2(μ-ADN)](BF4)2 (1), [Fe(μ-hbtz)2(μ-ADN)](BF4)2 (2), [Fe(μ-1ditz)2(GLN)2](BF4)2·GLN (3) and [Fe(μ-1ditz)2(μ-SUN)](BF4)2·SUN (4). It was established that the application of dinitriles allows an increase in the dimensionality of the ebtz and hbtz based systems while maintaining the structure of the polymeric units characteristic of previously studied mononitrile based analogues. In 3 and 4, regardless of the type of dinitrile coligand, the motif of 2D polymeric layers constituted by 1ditz molecules remains preserved. However, the dimensionality of 1ditz based networks is governed by the coordination modes of dinitriles. 3, based on a shorter molecule of glutaronitrile, crystallizes as a two-dimensional (2D) coordination polymer. In this compound, dinitriles coordinate monodentately or play the role of guest molecules. The substitution of glutaronitrile with suberonitrile enables the bridging of neighboring polymeric layers, resulting in a 3D network. The intentional selection of bis(tetrazoles) and dinitriles as building blocks has led, as expected, to obtaining systems with the structure of the first coordination sphere consisting of four tetrazole rings and two axially coordinated nitrile molecules. It created the conditions required for the occurrence of thermally induced spin crossover. Magnetic measurements and single crystal X-ray diffraction studies were used for the characterization of the spin crossover properties of 1–4. [ABSTRACT FROM AUTHOR]

Four salts of an anionic iron(III) bis-complex, [Fe(L L -thr)2]1−, were synthesized from water or methanol. H2L L -thr is a tridentate ligand derived from the L -threonine amino acid, and the cations used are Li+ (1), Na+ (2), K+ (3), and Ba2+ (4). Single-crystal X-ray diffraction showed that all the complexes are coordination polymers of different dimensionalities. The iron(III) complex binds to cations through its coordinated phenolate and non-coordinated carboxylate oxygen atoms. While Li+ forms a linear chain, all others have a pair of bridged cations intervening the iron(III) complexes. The 3D network of Ba2+ salt has a sizeable solvent-accessible space occupied by aquated chloride ions. The differences in circular dichroism (CD) spectra and significantly lower conductance values in water and methanol support partial retention of the polymeric nature in methanol. The visible spectra of 4 in methanol or water showed an ∼10 nm shift of the charge transfer bands from 3. However, the addition of Al3+ salt to 2 showed a significant colour shift. Further investigation confirmed that the colour shift is due to partial protonation of the complex with protons generated from salt hydrolysis. Most reports on visual aluminium detection consider aluminium's binding as the shift's source. The present results show that protonation due to hydrolysis of aluminium salt can skew the observation. [ABSTRACT FROM AUTHOR]

The accurate and rapid detection of antibiotics and heavy-metal-based toxic oxo-anions in water media employing coordination polymers (CPs) as luminescent probes has attracted a lot of attention. Three new Cd(II)-based ternary CPs derived from first-presented L ligands, including [Cd(DCTP)(L)(OH)]n (1), [Cd(TBTA)(L)(OH)]n (2), and [Cd(NPHT)(L)(H2O)]n (3) (L = 2-((1H-imidazol-1-yl)methyl)-5,6-dimethyl-1H-benzo[d]imidazole, H2DCTP = 2,5-dichloroterephthalic acid, H2TBTA = tetrabromoterephthalic acid and H2NPHT = 3-nitrophthalic acid), were successfully assembled and characterized. 1 and 2 show 2D hcb layers, which can be further extended into a 3D supramolecular framework via classic hydrogen bonding interactions. 3 features a 1D double chain that ultimately spreads into a 2D network through weak hydrogen bonding interactions. With the advantages of high stability and excellent luminescent properties, the three CPs display high sensitivity, selectivity, and good anti-interference for the sensing of pefloxacin (PEF) and Cr2O72− ions (LOD values toward PEF: 3.82 × 10−7 mol L−1 for 1, 4.06 × 10−7 mol L−1 for 2, and 1.36 × 10−8 mol L−1 for 3, and toward Cr2O72− ions: 5.97 × 10−7 mol L−1 for 1, 5.87 × 10−7 mol L−1 for 2, and 8.21 × 10−8 mol L−1 for 3). These CPs are the first examples of bifunctional luminescent sensors to detect PEF and Cr2O72− in aqueous solutions. The luminescence quenching mechanisms are explored in detail. [ABSTRACT FROM AUTHOR]

The adjustment of crystal symmetry and intramolecular magnetic coupling is of great importance for the construction of high-performance single-molecule magnets. By using an aggregation-induced-emission-active pyridine-carbohydrazone-based Schiff base ligand and phosphine oxides, four dinuclear and one one-dimensional DyIII-based complexes, [Dy2(TPE-pc)2(Bu3PO)2Cl2]·2CH3CN·2H2O (1), [Dy2(TPE-pc)2(Cy3PO)2Cl2] (2), [Dy2(TPE-pc)2(MePA)2Cl2]·2CH3OH (3), [Dy2(TPE-pc)2(Ph3PO)2Cl2]2 (4) and [Dy2(TPE-pc)2(DPPO)Cl2]n (5) (H2TPE-pc = (E)-N′-(2-hydroxy-5-(1,2,2-triphenylvinyl)benzylidene)picolinohydrazide, MePA = N-phenyl-N′,N′′-bis(morpholinyl) phosphoric triamide, DPPO = piperazine-1,4-diylbis(diphenyl phosphine oxide)), were isolated. All complexes are made up of an enol oxygen-bridged Dy2 unit, where DyIII ions possess a pentagonal bipyramidal geometry with pseudo D5h symmetry. Magnetic measurements reveal that intramolecular DyIII–DyIII couplings are ferromagnetic and all complexes display a significant slow magnetic relaxation phenomenon below 30 K under a zero dc field. Ab initio calculations indicate that the anisotropic magnetic axes of all DyIII ions are approximately perpendicular to the higher-order symmetric axes in all complexes, and that DyIII–DyIII magnetic couplings along the magnetic axes effectively suppress the ground state quantum tunneling effect of magnetization and promote the occurrence of slow magnetic relaxation. Raman relaxation prevails in all complexes. In addition, the H2TPE-pc ligand shows an aggregation-induced emission (AIE) effect; however, all complexes exhibit an aggregation-caused quenching (ACQ) phenomenon. [ABSTRACT FROM AUTHOR]

Herein, we report an efficient and straightforward approach for the synthesis of N-alkylated aminoquinoline derivatives by recyclable Cd-containing coordination polymer-catalyzed reactions of aminoquinolines with primary alcohols via the borrowing hydrogen strategy. In this work, a new type of coordination polymer [Cd(CIA)(phen)2(H2O)]n was successfully designed and fabricated. The molecular structure was corroborated by single-crystal X-ray diffraction and fully characterized by PXRD, FT-IR, TGA, and XPS. Importantly, this polymer revealed high catalytic activity for the N-alkylation reaction of 2-aminoquinoline and 8-aminoquinoline with inexpensive and low-toxicity alcohols as alkylating agents in excellent yields up to 95%. Interestingly, the present synthetic protocol was successfully applied for the gram-level synthesis of several biologically active compounds. In addition, several control reactions were carried out to investigate the possible mechanisms of this transformation. Finally, recycling experiments indicated that the cadmium coordination polymer showed good recovery performance for borrowing hydrogen reactions. [ABSTRACT FROM AUTHOR]