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The synthesis of ultrafine metal nanoparticles and their integration onto 2D nanomaterials have attracted significant interest due to their outstanding chemical and electrochemical activity. Among 2D materials, MXenes have emerged as promising candidates for hybridization owing to their abundant surface nucleation sites and high electrical conductivity. However, achieving uniform growth of ultrafine metal nanoparticles on MXene surfaces remains a challenge due to non‐uniform metal nucleation and growth behaviors. In this study, a novel coordination‐assisted surface functionalization method is presented to graft organic ligands onto MXene, promoting the uniform growth of ultrafine metal nanoparticles. By leveraging the mutual attraction between metal ions, organic ligands, and MXene surface functional groups, MXene surfaces are efficiently functionalized through palladium coordination complexes. Subsequent ligand‐induced growth facilitated the uniform nucleation of ultrafine metal nanoparticles, resulting in densely anchored nanoparticles of 1–3 nm in size on MXene. Comprehensive characterizations reveal the effectiveness of the method, demonstrating exceptional properties of the MXene‐metal nanoparticle hybrid, particularly in hydrogen sensing applications. This study highlights the potential of coordination‐assisted surface functionalization for the controlled synthesis of MXene‐based nanomaterials with tailored properties for diverse applications. [ABSTRACT FROM AUTHOR]

Encapsulation of a single protein within a confined space can lead to distinct properties compared to bulk solutions, but controlling the number of encapsulated proteins and their environment remains challenging. This study demonstrates the encapsulation of single proteins within well‐defined, tunable cavities of self‐assembled coordination cages, thereby enhancing protein stability. Within uniform cavities of size‐tunable coordination cages, 15 different proteins of varying sizes (3–6 nm in diameter) and properties (e.g., isoelectric points and hydrophobicity) were successfully confined. Various analytical techniques confirmed that the proteins maintained their secondary structures and enzymatic activities under denaturing conditions such as exposure to organic solvents, heat, and buffers. These findings suggest that such coordination cages have the potential to serve as synthetic hosts for precisely controlling protein functions within their customizable cavities. [ABSTRACT FROM AUTHOR]

In this work, two silver/copper‐based coordination compounds {[Ag(tty)]⋅NO3}n (1) and {[Cu2Cl2(tty)2(H2O)2]⋅Cl⋅NO3 ⋅ (H2O)2}n (2) (tty=1,2,4,5‐tetra(1H‐1,2,4‐triazol‐1‐yl))benzen), were synthesized using the different metal salts under the hydrothermal condition. Structural analyses show that compound 1 features tilted L‐shaped 1D Ag chains structure and compound 2 presents a 2D layer with free Cl−, NO3− and water molecules. The experimental results reveal that 1 displays considerably high thermal stability with the thermal decomposition temperature above 337 °C compared to compound 2, which further exemplifies that the framework structures may have a crucial effect on the resultant thermal stability. Additionally, the non‐isothermal kinetics parameters were evaluated at different heating rates by Kissinger's and Ozawa‐Doyle's methods. Importantly, the kinetic triplets (the apparent activation energy (Ea), the preexponential factor (logA) and the mechanism function (ƒ(α)) and the related thermodynamic parameters (the Gibbs energy of activation, ▵G≠, the enthalpy of activation, ▵H≠, and the entropy of activation, ▵S≠) of the thermal decomposition processes are discussed and calculated in detail. [ABSTRACT FROM AUTHOR]

The preparation and characterization of two novel europium–azobenzene complexes that demonstrate the effectiveness of this ligand for stabilizing reactive, redox-active metals are reported. With the family of rare earth metals receiving attention due to their potential as catalysts, critical components in electronic devices, and, more recently, in biomedical applications, a detailed understanding of factors contributing to their coordination chemistry is of great importance for customizing their stability and reactivity. This study introduces azobenzene as an effective nonprotic ligand system that provides novel insights into rare earth metal coordination preferences, including factors contributing to the coordinative saturation of the large, divalent europium centers. The two compounds demonstrate the impact of the solvent donors (tetrahydrofuran (THF) and dimethoxyethane (DME)) on the overall coordination chemistry of the target compounds. Apart from the side-on coordination of the doubly-reduced azobenzene and the anticipated N-N bond elongation due to decreased bond order, the two compounds demonstrate the propensity of the europium centers towards limited metal-π interactions. The target compounds are available by direct metallation in a straightforward manner with good yields and purity. The compounds demonstrate the utility of the azobenzene ligands, which may function as singly- or doubly-reduced entities in conjunction with redox-active metals. An initial exploration into the computational modeling of these and similar complexes for subsequent property prediction and optimization is performed through a methodological survey of structure reproduction using density functional theory. [ABSTRACT FROM AUTHOR]

Pnictogen pincer complexes are a fascinating class of compounds due to their dynamic molecular and electronic structures, and valuable stoichiometric or catalytic reactivity. As recognition of their unique chemistry has grown, so too has the library of pincer ligands employed and pnictogen centres engaged to prepare them. Here we computationally study how the choice of pincer ligand framework and pnictogen influence the electronic and steric outcomes within the complexes obtained. The most relevant electronic parameter is the pnictogen‐centred electrophilicity, which has been quantified by fluoride ion affinities and LUMO energies, while the most relevant steric parameter is the crowding around the central pnictogen, which has been quantified by the %Vbur values and visualized using steric maps. The resulting trends are analyzed with reference to binding pocket size, acceptor orbital type, electronic delocalization, π‐donor strengths, and heteroatom incorporation. Thus, considering 16 ligand frameworks and 4 heavy pnictogen centres, this study provides a broad‐spectrum view of stereo‐electronic variation in pnictogen pincer complexes, which, together with a recent study on geometric variation in the same family, provides a substantial dataset to guide future molecular design and reactivity studies. [ABSTRACT FROM AUTHOR]

A series of isostructural early actinide AnIV complexes was synthesized in order to investigate the influence of a conjugated framework in the ligand backbone on An bonding. Therefore, the AnIV complexes [An(pyrophen)2] (An = Th, U, Np, and Pu) with the pure N–donor ligand bis(2‐pyrrolecarbonylaldehyde)‐o‐phenylenediamine referred to as pyrophen, were synthesized and characterized. Solid state analysis via single‐crystal X‐ray diffraction (SC‐XRD) reveals two sets of ligands binding in an almost orthogonal arrangement to the actinide center. For the larger actinides Th and U, the coordination sphere allows for additional coordination by a solvent molecule. Nuclear magnetic resonance spectroscopy (NMR) studies show the presence of highly symmetrical complexes in solution in good agreement with the solvent‐free solid structures. While SC‐XRD suggests mainly ionic binding, an analysis of paramagnetic NMR contributions and quantum chemical bond analysis hint towards significant covalency in the U, Np, and Pu compounds. This series of An complexes allowed for a thorough structural and theoretical comparison of a conjugated system to a closely related N‐donor ligand (pyren)[1] as well as to the mixed N,O Schiff base ligands salophen (conjugated) and salen (non‐conjugated). [ABSTRACT FROM AUTHOR]

Weakly‐coordinating anions (WCAs) are employed in a wide range of applications, but limitations remain, including high reactivity, limited redox window, complicated synthesis, high cost, low solublity, and low structural tunabililty. Herein, we report a new class of WCA based on alkyl or aryl (R) substituted silicates bearing fluorinated pinacolate ligands, “[RSiF24]−”. Anions bearing a variety of R groups were prepared, enabling facile tuning of sterics and solubility. A range of cations employed in chemical reactivity has been supported by these anions, including ether‐free alkali cations, Ag+, Ph3C+, Fc+, [NiI(COD)2]+. [Pd(dppe)(NCMe)Me]+ has been generated by salt metathesis or protonation of a metal‐alkyl bond, showcasing the ability of the [RSiF24]− anions to support applications in coordination chemistry and catalysis. Electrochemical studies on the [Bu4N]+ variant show an exceptionally wide stability window for the [MeSiF24]− anion of 7.5 V in MeCN. CV experiments demonstrate reversible Mg deposition and stripping. [ABSTRACT FROM AUTHOR]

Unlike cyclopropanes, the analogous B2C species (diboriranes) tend to adopt non‐classical Hückel‐aromatic structures with bridging moieties R between the boron atoms. The coordination of the thus generated cyclic 2e− π‐system to transition metals is completely unexplored. We here report that complexation of non‐classical diboriranes cyclo‐μ‐RB2Dur2CPh (R=H, SnMe3; Dur=2,3,5,6‐tetramethylphenyl) to Fe(CO)3 fragments allows for the carbonylative ring expansion of the B2C ring to either four‐ or five‐membered rings depending on the nature of the BRB 3‐center‐2‐electron bond (3c2e): The H‐bridged diborirane (R=H) initially reacts with Fe2(CO)9 to the allylic π‐complex with an agostic BH/Fe interaction. Subsequent formal hydroboration of CO from excess Fe2(CO)9 results in the side‐on ring expansion under formation of a five‐membered B2C2O ring, coordinated to the Fe(CO)3 moiety. In contrast, in case of the stannyl‐bridged diborirane (R=SnMe3) under the same conditions, CO is added end‐on to the B−B bond with the carbon terminus formally inserting into the B2Sn 3c2e‐bond. The two carbonylative ring expansion products can also be described as nido and closo clusters, respectively, according to the Wade‐Mingos rules. [ABSTRACT FROM AUTHOR]

Reductive proton‐coupled electron transfer (PCET) has important energetic implications in numerous synthetic and natural redox processes. The development of catalytic systems that can mediate such transformations has become an attractive target, especially when light is used to generate the reactive species towards solar‐to‐chemicals conversion. However, such approach becomes challenged by kinetic competition with H2 evolution. Here we describe the excited state reactivity of a molecular Zr‐based platform under visible light irradiation for the efficient reduction of multiple bonds. Mechanistic investigations shine light on a charge separation process that colocalizes an excited electron and an acidic proton to promote selective PCET. We further leveraged this reactivity for the photocatalytic reduction of a variety of organic substrates. Our results demonstrate the promise of this molecular platform to design strong photocatalytic PCET mediators for reductive transformations. More broadly, we also show the potential relevance of PCET mechanisms in the (photo)redox chemistry of Zr‐based molecular materials. [ABSTRACT FROM AUTHOR]

Geometrically‐constrained pnictogen pincer complexes have emerged in recent years as platforms for unique stoichiometric and catalytic chemical transformations. These complexes feature dynamic conformations ranging from fully planar at the pnictogen centre to distorted‐pyramidal geometries, as well as variation between phases. Although the valued reactivity of pnictogen pincer complexes is ascribed to their geometries, there is no unified model to explain the observed conformational outcomes across different ligands and pnictogen centres. Here we propose such a model through computational analysis of more than 1300 structures across 64 complexes (16 ligands and 4 heavy pnictogens), explaining the experimental observations and making new predictions. By looking at signatures of bond stability (bond lengths, Wiberg bond indices) and delocalization (NPA charges, Hirshfeld charges), our framework posits a pnictogen‐based σ‐bonding effect that favours pyramidalization and exists in competition with a ligand‐based π‐bonding effect that favours planarity. Variations in structure as a function of pnictogen identity, ligand tethering, electronics, and aromaticity can be reconciled with reference to a balance between these two opposing forces. Careful consideration of the σ/π‐bonding effects may aid in the rational design of future pnictogen pincer complexes with predictable geometries and reactivities. [ABSTRACT FROM AUTHOR]

Cyclic amino(alkyl) and cyclic amino(aryl) carbenes (cAACs/cAArCs) have been established as very useful ligands for catalytic and photonic applications of transition metal complexes. Herein, we describe the synthesis of a structurally related sterically demanding, electrophilic [2.2]isoindolinophanyl‐based carbene (iPC) that bears a [2.2]paracyclophane moiety. The latter leads to more delocalized frontier orbitals and intense green fluorescence of (HiPC)OTf (2) from an intra‐ligand charge transfer (1ILCT) state in the solid state. Base‐promoted synthesis of the free carbene led to an unusual ring expansion and subsequent dimerization reaction, but the beneficial ligand properties can be exploited by trapping in situ at a metal center. The iPC ligand is a very potent π‐chromophore, which participates in low energy metal‐to‐ligand (ML)CT transitions in [RhCl(CO)2(iPC)] (4) and IL‐"through‐space"‐CT transitions in [Au(iPC)2]OTf (5). The steric demand of the iPC leads to high stability of 5 against air, moisture, or solvent attack, and ultralong‐lived green phosphorescence with a lifetime of 185 μs is observed in solution. The beneficial photophysical and electronic properties of the iPC ligand, including a large accessible π surface area, were exploited by employing highly efficient energy transfer (EnT) photocatalysis in a [2+2] styrene cycloaddition reaction using 5, which outperformed other established photocatalysts in comparison. [ABSTRACT FROM AUTHOR]

Given their high safety, environmental friendliness and low cost, aqueous zinc-ion batteries (AZIBs) have the potential for high-performance energy storage. However, issues with the structural stability and electrochemical kinetics during discharge/charge limit the development of AZIBs. In this study, vanadium oxide electrodes with organic molecular intercalation were designed based on intercalating 11 kinds of charged organic carboxylic acid ligands between 2D layers to regulate the interlayer spacing. The negatively charged carboxylic acid group can neutralize Zn2+, reduce electrostatic repulsion and enhance electrochemical kinetics. The intercalated organic molecules increased the interlayer spacing. Among them, the 0.028EDTA · 0.28NH4+ · V2O5 · 0.069H2O was employed as the cathode with a high specific capacity (464.6 mAh g−1 at 0.5 A g−1) and excellent rate performance (324.4 mAh g−1 at 10 A g−1). Even at a current density of 20 A g−1, the specific capacity after 2000 charge/discharge cycles was 215.2 mAh g−1 (capacity retention of 78%). The results of this study demonstrate that modulation of the electrostatic repulsion and interlayer spacing through the intercalation of organic ligands can enhance the properties of vanadium-based materials. [ABSTRACT FROM AUTHOR]

We report on the synthesis and characterization of Mn(III) chloride (MnIIICl3) complexes coordinated with N-oxide ylide ligands, namely trimethyl-N-oxide (Me3NO) and pyridine-N-oxide (PyNO). The compounds are reactive and, while isolable in the solid-state at room temperature, readily decompose into Mn(II). For example, "[MnIIICl3(ONMe3)n]" decomposes into the 2D polymeric network compound complex salt [MnII(µ-Cl)3MnII(µ-ONMe3)]n[MnII(µ-Cl)3]n·(Me3NO·HCl)3n (4). The reaction of MnIIICl3 with PyNO forms varied Mn(III) compounds with PyNO coordination and these react with hexamethylbenzene (HMB) to form the chlorinated organic product 1-cloromethyl-2,3,4,5,6-pentamethylbenzene (8). In contrast to N-oxide coordination to Mn(III), the reaction between [MnIIICl3(OPPh3)2] and 2,2,6,6-tetramethyl-1-piperidinyloxy (TEMPO) resulted in electron transfer-forming d5 manganate of the [TEMPO] cation instead of TEMPO–Mn(III) adducts. The reactivity affected by N-oxide coordination is discussed through comparisons with other L–MnIIICl3 complexes within the context of reduction potential. [ABSTRACT FROM AUTHOR]

In this section of Resonance, we invite readers to pose questions likely to be raised in a classroom situation. We may suggest strategies for dealing with them, or invite responses, or both. "Classroom" is equally a forum for raising broader issues and sharing personal experiences and viewpoints on matters related to teaching and learning science. This article presents an experimental module that provides rich observations for deriving a spectrochemical series of ligands, one of the key topics in coordination chemistry. The experiment involves the reaction of Co(II) aqueous solution with different ligand solutions. The module includes guiding and reflective questions as part of prelab and postlab sections. These questions are aimed at enhancing the learning of concepts associated with the experiment. The implementation of the module is structured as a jigsaw puzzle, providing an opportunity for collaborative group interactions to arrive at the spectrochemical series. The technical requirements of the module are minimal, making it suitable for adoption in any undergraduate (UG) chemistry lab. [ABSTRACT FROM AUTHOR]

The major source of fluoride, namely calcium difluoride (CaF2), is derived from the mineral fluorspar. Recent advances in the activation of CaF2 via mechanochemical methods have inspired investigation of the fundamental properties of Ca–F bonds in molecular complexes. However, the paucity of well‐defined molecular Ca–F‐containing complexes undermines systematic understanding of the factors governing nucleophilic fluoride delivery. Here we report the use of a multidentate bis(phenoxide) ligand based on a 1,4,7‐triazacyclononane (TACN) scaffold for the formation of well‐defined Ca–F complexes and demonstrate their capabilities in fluoride delivery. Key to this synthesis is a desymmetrization step carried out on the TACN ligand within the Ca coordination sphere. A series of stable anionic dinuclear calcium fluoride complexes has then been accessed and characterized by NMR spectroscopy (critically by 19F NMR) and X‐ray crystallography. Nucleophilic fluoride delivery can be used to generate C−F, Si–F and S−F bonds, with a notable advance over amide‐derived ligand scaffolds being the reduced extent of side reactions derived from competing attack on the electrophile by the less nucleophilic O‐donor anionic ligand set. [ABSTRACT FROM AUTHOR]

A full selectivity control over the catalytic hydrogenation of nitroaromatics leads to the production of six possible products, i.e., nitroso, hydroxylamine, azoxy, azo, hydrazo or aniline compounds, which has however not been achieved in the field of heterogeneous catalysis. Currently, there is no sufficient evidence to support that the catalytic hydrogenation of nitroaromatics with the use of heterogeneous metal catalysts would follow the Haber's mechanistic scheme based on electrochemical reduction. We now demonstrate in this work that it is possible to fully control the catalytic hydrogenation of nitroaromatics into their all six products using a single catalytic system under various conditions. Employing SnO2‐supported Pt nanoparticles facilitated by the surface coordination of ethylenediamine and vanadium species enabled this unprecedented selectivity control. Through systematic investigation into the controlled production of all products and their chemical reactivities, we have constructed a detailed reaction network for the catalytic hydrogenation of nitroaromatics. Crucially, using oxygen‐isolated characterization techniques is essential for identifying unstable compounds such as nitroso, hydroxylamine, hydrazo compounds. The insights gained from this research offer invaluable guidance for selectively transforming nitroaromatics into a wide array of functional N‐containing compounds, both advancing fundamental understanding and fostering practical applications in various fields. [ABSTRACT FROM AUTHOR]

The reaction of titanium(IV) chloride with sodium hexafluoroisopropoxide, carried out in hexafluoroisopropanol, produces titanium(IV) hexafluoroisopropoxide, which is a liquid at room temperature. Recrystallization from coordinating solvents, such as acetonitrile or tetrahydrofuran, results in the formation of bis‐solvate complexes. These compounds are of interest as possible Ziegler–Natta polymerization catalysts. The acetonitrile complex had been structurally characterized previously and adopts a distorted octahedral structure in which the nitrile ligands adopt a cis configuration, with nitrogen lone pairs coordinated to the metal. The low‐melting tetrahydrofuran complex has not provided crystals suitable for single‐crystal X‐ray analysis. However, the structure of chloridotris(hexafluoroisopropoxido‐κO)bis(tetrahydrofuran‐κO)titanium(IV), [Ti(C3HF6O)3Cl(C4H8O)2], has been obtained and adopts a distorted octahedral coordination geometry, with a facial arrangement of the alkoxide ligands and adjacent tetrahydrofuran ligands, coordinated by way of metal–oxygen polar coordinate interactions. [ABSTRACT FROM AUTHOR]

The mode of coordination of copper(II) ions with dopamine (DA, L) in the binary, as well as ternary systems with Ado, AMP, ADP, and ATP (L′) as second ligands, was studied with the use of experimental—potentiometric and spectroscopic (VIS, EPR, NMR, IR)—methods and computational—molecular modeling and DFT—studies. In the Cu(II)/DA system, depending on the pH value, the active centers of the ligand involved in the coordination with copper(II) ions changed from nitrogen and oxygen atoms (CuH(DA)3+, Cu(DA)2+), via nitrogen atoms (CuH2(DA)24+), to oxygen atoms at strongly alkaline pH (Cu(DA)22+). The introduction of L′ into this system changed the mode of interaction of dopamine from oxygen atoms to the nitrogen atom in the hydroxocomplexes formed at high pH values. In the ternary systems, the ML′-L (non-covalent interaction) and ML′HxL, ML′L, and ML′L(OH)x species were found. In the Cu(II)/DA/AMP or ATP systems, mixed forms were formed up to a pH of around 9.0; above this pH, only Cu(II)/DA complexes occurred. In contrast to systems with AMP and ATP, ternary species with Ado and ADP occurred in the whole pH range at a high concentration, and moreover, binary complexes of Cu(II) ions with dopamine did not form in the detectable concentration. [ABSTRACT FROM AUTHOR]

Rapid detection of potentially toxic heavy metals like Hg(II) has attracted great attention in the last few decades due to the importance to maintain a safe and sustainable environment for human beings. Coordination chemistry and concepts therein, play an important role in the detection of Hg(II). Size, charge, and nature of the donor atom and the respective cation (metal ion), are crucial in selective interactions between the sensor and metal ions. The sensors designed for the purpose, coordinate to Hg(II) ion through various donor sites, coordination causes a change in the electron density in organic molecules and results in either visible color change or enhancing/quenching fluorescence intensity. Since Hg(II) is soft metal, with d10 electron system, so majority of the sensors have soft donor sites which prefer to coordinate with Hg(II). Oxygen is also present in some chelating ligands which is least preferred coordination site, due to its hard nature. There are several reports of replacing other ligating sites by sulfur for enhanced mercury sensing. In some cases, desulfurization is being detected as clear change in spectral behavior during the sensing process. Efforts are still in progress to design and introduce a sensor with utmost sensitivity and selectivity. In this review, we made an attempt to explain the coordination aspects of Hg(II) detectors, reasons for poor efficiency and possible suggestions to improve the selection criterion of various compounds. It will help researchers to know about important concepts in designing more sensitive and selective sensors for detection of Hg(II) in environmental and biological samples. [ABSTRACT FROM AUTHOR]

Transition metal complexes have historically played a pivotal role in creating vibrant pigments utilized across artistic mediums such as ceramics, paintings, and glass mosaics. Despite their extensive historical use, our understanding of the mechanisms governing transition metal complex behavior has predominantly emerged in recent times, leaving numerous aspects of this process ripe for exploration. These complexes exhibit striking color variations under diverse conditions when employed in pigment formulations. This review utilizes a bottom-up scientific approach, spanning from microscopic to macroscopic scales, to unravel the molecular origins of the colors generated by transition metal complexes in pigments and ceramic glazes. Advanced spectroscopy techniques and computational chemistry play pivotal roles in this endeavor, highlighting the significance of understanding and utilizing analytical data effectively, with careful consideration of each technique’s specific application. Furthermore, this review investigates the influence of processing conditions on color variations, providing valuable insights for artists and manufacturers aiming to enhance the precision and quality of their creations while mitigating environmental impact.

The novel and exciting class of porphyrin‐based compounds are the main group coordination‐driven porphyrins (MGCPs) with a central main group element into the porphyrin macrocycle. MGCPs have unique properties, reactivity, and potential applications in catalysis, sensing, biomedicine etc. This comprehensive review article discusses recent advances in the field of main group coordination driven porphyrins and explores some of its potential uses in solar cells, catalysis, antimicrobial, optoelectronic devices, sensing, and catalysis. The addition of main group elements to porphyrin systems has resulted in the production of entirely novel compounds that have intriguing qualities including increased stability and catalytic activity. Significant modifications in these unique compounds features are apparent through the analysis of their structural properties. It encompasses FTIR, proton NMR, electrical and optical characterisation in addition to an electrochemical analysis of those parameters. They serve as significant building blocks for the creation of cutting‐edge materials and technologies in a variety of scientific and technical disciplines because to their special qualities and adaptability. Researchers working in the domains of coordination chemistry, catalysis, and materials science will find this study to be of interest since it offers a thorough examination of current developments in main group coordination driven porphyrins and their prospective applications. Overall, main group porphyrins are used in many different fields, such as sensing, catalysis, and optoelectronic devices. [ABSTRACT FROM AUTHOR]

Helical nanostructures fabricated via the self‐assembly of artificial motifs have been a captivating subject because of their structural aesthetics and multiple functionalities. Herein, we report the facile construction of a self‐assembled nanohelix (NH) by leveraging an achiral aggregation‐induced emission (AIE) luminogen (G) and pillar[5]arene (H), driven by host–guest interactions and metal coordination. Inspired by the “sergeants and soldiers” effect and “majority rule” principle, the host–guest complexation between G and H is employed to fixate the twisted conformation of G for the generation of “contortion sites”, which further induced the emergence of helicity as the 1D assemblies are formed via Ag(I) coordination and hexagonally packed into nano‐sized fibers. The strategy has proved feasible in both homogeneous and heterogeneous syntheses. Along with the formation of NH, boosted luminescence and enhanced productivity of reactive oxygen species (ROS) are afforded because of the efficient restriction on G, indicating the concurrent regulation of NH′s morphology and photophysical properties by supramolecular assembly. In addition, NH also exhibits the capacity for bacteria imaging and photodynamic antibacterial activities against Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli). [ABSTRACT FROM AUTHOR]

The design and study of rich, bulky phosphorus ligands is a key area of research for homogeneous catalysis. Here, we describe an original strategy using a hydrophosphination reaction to produce phosphines of interest for coordination chemistry and homogenous catalysis. In particular, the phosphine obtained by reacting diphenylphosphine with acenaphthylene (ligand 2) gives a ligand that adopts an unusual spatial geometry. The coordination chemistry of the ligand has been investigated with Au(I), Ag(I), Cu(I), and Pd(II), for which a complete characterization could be made, particularly in X-ray diffraction studies. The reactivity of some of these complexes has been demonstrated, particularly in Pd-catalyzed cross-coupling reactions and Au-catalyzed hydroaminations and in the hydration of alkynes. [ABSTRACT FROM AUTHOR]

Metal complexes of benzotriazole-type ligands continue to attract the intense interest of many inorganic chemistry groups around the world for a variety of reasons, including their aesthetically beautiful structures, physical properties and applications. 1-methylbenzotriazole (Mebta) is the N-substituted archetype of the parent 1H-benzotriazole. The first attempt to build a "periodic table" of Mebta, which includes its complexes with several metal ions, is described in this work. This, at first glance, trivial ligand has led to interesting results in terms of the chemistry, structures and properties of its metal complexes. This work reviews the to-date published coordination chemistry of Mebta with Mn(II), Fe(II), Fe(III), Co(II), Ni(II), Cu(I), Cu(II), Zn(II), Pd(II), Au(I) and {UVIO2}2+, with emphasis on their preparations, reactivity, structures and properties. Unpublished results from our group comprising other Co(II), Ni(II), Cu(II) and Zn(II) complexes, as well as Cd(II), Hg(II), Ag(I), In(III) and Sn(IV) ones are briefly reported. Mebta can also provide access to 1D and 3D heterometallic thiocyanato-bridged Co(II)/Hg(II) and Ni(II)/Hg(II) compounds. In almost all cases, Mebta behaves as a monodentate ligand with the nitrogen of position 3 of the azole ring as the donor atom. However, there are two copper complexes in which this molecule adopts a bidentate bridging coordination behavior. Our efforts to complete the "periodic table" of Mebta are continued. [ABSTRACT FROM AUTHOR]

AbstractAll the data recently reported for the purported air/water stable PrIV complex, [(L)PrIV(L)4(OH0.94Cl0.06)2PrIV(L)]n (L = N-acetylanthranilate) [1], have been reinterpreted to show that it is, in fact, the PrIII complex [Pr2L6(H2O)2]n. Importantly, it is isomorphous with its reported EuIII analogue [Eu2L6(H2O)2]n [2], providing further evidence of the incorrect assignment in the literature. [ABSTRACT FROM AUTHOR]

We report the synthesis of a novel class of metal-complexing peptide-based polymers, which we name HyperMAPs (Hyper -loaded M et A l-complexed P olymers). The controlled solid-phase synthesis of HyperMAPs' scaffold peptide provides our polymer with a well-defined molecular structure that allows for an accurate on-design assembly of a wide variety of metals. The peptide-scaffold features a handle for direct conjugation to antibodies or any other biomolecules by means of a thiol-maleimide-click or aldehyde-oxime reaction, a fluorogenic moiety for biomolecule conjugation tracking, and a well-defined number of functional groups for direct incorporation of metal-chelator complexes. Since metal-chelator complexes are prepared in a separate reaction prior to incorporation to the peptide scaffold, polymers can be designed to contain specific ratios of metal isotopes, providing each polymer with a unique CyTOF spectral fingerprint. We demonstrate the complexing of 21 different metals using two different chelators and provide evidence of the application of HyperMAPs on a 13 parameter CyTOF panel and compare its performance to monoisotopic metal-conjugated antibodies. • Current metal chelating polymers for use in mass cytometry design limits amount of metals. • Complexing metals to chelators before attachment to a scaffold provides better quality control. • Our design enables 21 metals and demonstrates similar signal to current polymers. • Spectral deconvolution of multi-isotopic signal is shown, enabling combining isotopes per marker. [ABSTRACT FROM AUTHOR]

Morphological anisotropic engineering is powerful to synthesize metal–organic frameworks (MOFs) with versatile physicochemical properties for diverse applications ranging from gas storage/separation to electrocatalysis and batteries, etc. Herein, we developed a carbon substrate guided strategy to manipulate the facet‐dependent coordination for morphology engineering of Fe‐THBQ (tetrahydroxy‐1,4‐benzoquinone) frameworks, which is built with cubic Fe octamer bridged by two parallel THBQ ligands along three orthogonal axes, extending to a three‐dimensional (3D) framework with pcu‐e network topology. The electronegative O‐containing functional groups on carbon surfaces compete with THBQ linkers to selectively interact with the unsaturated coordinated Fe cations on the {111} facets and inhibit crystal growth along the <111> direction. The morphology of Fe‐THBQ evolves from thermodynamically favored truncated cube to cuboctahedron depending on the content of O‐containing functional groups on the carbon substrate. The Fe‐THBQ with varied morphologies exhibits facet‐dependent performances for electrochemical lithium storage. This work will shed light on the morphology modulation of MOFs for promising applications. [ABSTRACT FROM AUTHOR]

The first example of a bis(cyaphido) complex, trans‐[Ru(dppe)2(C≡P)2], is described, unequivocally demonstrating the synthetic accessibility and stability of complexes that feature more than one cyaphido ligand. Synthesis is achieved from the precedent cation [Ru(dppe)2(C≡P)]+ via sequential coordination and desilylation of the phosphaalkyne Me3SiC≡P. The heteroleptic analogue trans‐[Ru(dppe)2(C≡N)(C≡P)] is also prepared from the same cation and NaCN; both cyaphido complexes are structurally characterized, enabling the first direct comparison of cyaphide with cyanide, its isoelectronic and isolobal counterpart. This demonstrates an enhanced π‐acidity for −C≡P over −C≡N, while computational studies reveal also a higher π‐donor character for the cyaphido ligand. [ABSTRACT FROM AUTHOR]

Manganese is currently experiencing a great deal of attention in homogeneous catalysis as a sustainable alternative to platinum group metals due to its abundance, affordable price and low toxicity. While homogeneous nitrogen fixation employing well‐defined transition metal complexes has been an important part of coordination chemistry, manganese derivatives have been only sporadically used in this research area. In this contribution, the authors systematically cover manganese organometallic chemistry related to N2 activation spanning almost 60 years, identify apparent pitfalls and outline encouraging perspectives for its future development. [ABSTRACT FROM AUTHOR]

Multicomponent supramolecular self-assembled systems can potentially harness the properties of multiple systems simultaneously. However, creating multicomponent supramolecular nanostructures with narrow size distributions is challenging due to the dynamic nature of noncovalent interactions. In this article, we report the coassembly of a tris-Ni-(II)-salphen and a tris-Cu-(II)-salphen complex. Co-assembly of the complexes afforded nanofibers with low dispersity, with the metal complexes homogeneously distributed throughout the nanofibers. The length of the nanofibers could also be tuned by varying the ratio of the metal complexes. Density functional theory (DFT) calculations indicate that the dimerization of the copper-(II) complex is unfavorable, unlike the dimerization of the nickel-(II) complex. Co-assembly with the copper-(II) complex inhibits the self-assembly of the nickel-(II) complex, enabling length control of the bimetallic nanofibers. These results could pave the way for designing multicomponent supramolecular systems with applications in catalysis and magnetic devices. [ABSTRACT FROM AUTHOR]

The performance of lithium‐sulfur batteries is compromised by the loss of sulfur as dissolved polysulfides in the electrolyte and consequently the polysulfide redox shutting effect. Accelerating the conversion kinetics of polysulfide intermediates into sulfur or lithium sulfide through electrocatalysis has emerged as a root‐cause solution. Co−N−C composite electrocatalyst is commonly used for this purpose. It is illustrated here that how the effectiveness can be improved by modulating the coordination chemistry of Co−N−C catalytic sites through introducing Ru species (RuCo−NC). The well‐dispersed Ru in the Co−NC carbon matrix altered the total charge distribution over the Co−N−C catalytic sites and led to the formation of electron‐rich Co−N, which is highly active for the polysulfide conversion reactions. Using Ru to modulate the electronic structure in the Co−N−C configuration and the additional catalytic sites over the Ru−Nx species can manifest optimal adsorption behavior of polysulfides. Consequently, the sulfur cathode with RuCo−NC can reduce the capacity fade rate from 0.11 % per cycle without catalyst (initial capacity of 701 mAh g−1) to 0.054 % per cycle (initial capacity of 1074 mAh g−1) over 400 cycles at 0.2 C rate. The results of this study provide the evidence for a feasible catalyst modification strategy for the polysulfide electrocatalysis. [ABSTRACT FROM AUTHOR]

Halide perovskite materials have gained enormous attention for their semiconducting properties, higher power conversion efficiency and potential applications in a wide range of fields of study, along with their two key limitations: stability and toxicity. Despite great progress made on halide perovskites and many promising research developments, the issues of stability and toxicity have not been fully resolved. Therefore, the coordination engineering of a new framework to obtain alternative new halide perovskite materials and a fundamental understanding of the coordination chemistry and electronic interactions forming the structure of these newly engineered halide perovskite materials are possible ways to overcome the issues related to both stability and toxicity. In this review, we comprehensively review the current development of halide perovskite families, both lead halide perovskites and lead-free halide perovskites, followed by the coordination engineering of the new frameworks to engineer new halide perovskite materials. All concerns regarding the fundamental ideas of coordination chemistry and electronic interactions are vital in forming halide perovskite structures and thus form the main aim of this review. We also discuss recent potential energy applications beyond photovoltaics and thus answer an essential and open question, 'what could happen in the future of halide perovskites?' in order to excite commercial enterprises and research institutions again as well as to motivate new predictions on the future continuity of this field. [ABSTRACT FROM AUTHOR]

The syntheses, coordination chemistry, and Mössbauer spectroscopy of hepta-iron(III) complexes using derivatised salicylaldoxime ligands from two categories; namely, 'single-headed' (H2L) and 'double-headed' (H4L) salicylaldoximes are described. All compounds presented here share a [Fe3-µ3-O] core in which the iron(III) ions are µ3-hydroxo-bridged in the complex C1 and µ3-oxo-bridged in C2 and C3. Each compound consists of 2 × [Fe3-µ3-O] triads that are linked via a central [Fe(µ2-OH)6]3- ion. In addition to the charge balance and microanalytical evidence, Mössbauer measurements support the fact that the triads in C1 are µ3-OH bridged and are µ3-O bridged in C2 and C3. [ABSTRACT FROM AUTHOR]

A synthetic route to the preparation of cobalt(III) complexes coordinated by bidentate phenylthioether ligands is described. Complexes of the type ((2-(X-phenylthio)ethylamine)- N , S)bis(ethylenediamine)cobalt(III) perchlorate, [(en)2Co(S (X-phenyl)CH2CH2 N H2)](ClO4)3, where X = 4-methoxy (2a), 4-methyl (2b), 3-methyl (2c), nothing (2d), 3-methoxy (2e), 4-bromo (2f) and 3-bromo (2g) were prepared. The synthetic route involves reaction of trans -dichloridobis(ethylenediamine)cobalt(III) chloride with NH2CH2CH2SC6H4X to produce cis -[(en)2CoCl(N H2CH2CH2SC6H4X)]Cl2 (1a – g). Formation of the Co–S bond, completing the ring closure, is then accomplished by removing the coordinated chlorido by addition of AgClO4 in sulfolane. Complexes were characterized by 1H and 13C NMR spectroscopy, UV-Vis spectroscopy and elemental analysis. In addition, the solid-state structure (X-ray) of the monohydrate of 2d confirms the coordination mode of the ligand. Preliminary kinetic investigations in basic solution show that the Co–S bond is broken resulting in the formation of [(en)2Co(OH)(N H2CH2CH2SC6H4X)]2+. At 15.0°C, a Hammett Plot is linear (r 2 = 0.981) with ρ = 2.24 ± 0.13. We have prepared a series of cobalt(III) complexes coordinated in a κ 2N,S manner by substituted phenylthioether ligands. The preparation is a two-step process starting with trans- dichloridobis(ethylenediamine)cobalt(III) chloride. NMR spectroscopy was used to characterize the complexes. In addition, the presence of an intense ligand-to-metal charge-transfer transition in the UV region confirms that a sulfur atom is bonded to the cobalt(III) center. In basic solution, the Co–S bond is broken, presumably by the classical SN1CB mechanism. The rate of the cleavage reaction increases as the electron-withdrawing ability of the phenyl substituent increases. (Image credit: Lee Roecker.) [ABSTRACT FROM AUTHOR]

Electrochemical biosensors are critical in advancing biomedical and pharmaceutical therapies because of their adaptability and cost-effectiveness. Voltammetric and amperometric sensors are of particular interest. These sensors typically consist of a specialized tip or biorecognition element and a transducer that converts biological data into readable signals. Efficient biosensor materials are essential for addressing health emergencies, with coordination polymers (CPs) and metal–organic frameworks (MOFs) showing promise. Functionalization strategies are necessary to enhance the usability of pristine MOFs, owing to issues such as low conductivity. The integration of conductive polymers with MOFs has resulted in the development of highly efficient biosensors. Both enzymatic and nonenzymatic biosensors are used for analyte detection; nonenzymatic approaches are gaining popularity owing to their durability and accuracy. MOFs and CPs have been applied in sensitive electrochemical biosensors to detect fatal brain tumors such as glioblastomas (GBM). These biosensors demonstrate enhanced selectivity and sensitivity, highlighting the potential of MOFs and CPs in advancing electrochemical biosensor technology for both in vivo and in vitro applications. [ABSTRACT FROM AUTHOR]

A simple direct condensation of 2,6‐bis(phenylamino)pyridine (1) and ClPPh2 under basic conditions allowed straightforward synthesis of the new multidentate Ph2P‐substituted anilido‐pyridine proligands 2 a and 2 b. Proligand 2 a was used in σ‐bond metathesis reactions with Me3Al affording either dinuclear product 3 a‐Al2 or mononuclear 4 a‐Al, depending on the reaction conditions. These complexes were authenticated by X‐ray crystallography, NMR spectroscopy and microanalysis. The analysis of the interaction between Me2Al and Ph2P fragments in 4 a‐Al was performed by structural and computational studies. The reactivity of 4 a‐Al was preliminary assessed in several representative reactions. [ABSTRACT FROM AUTHOR]

The conceptual replacement of nitrogen with phosphorus in common organic functional groups unlocks new properties and reactivity. The phosphorus‐containing analogues of triazenes are underexplored but offer great potential as flexible and small bite‐angle ligands. This manuscript explores the synthesis and characterisation of a family of air‐stable azophosphine‐borane complexes, and their subsequent deprotection to the free azophosphines. These compounds are structurally characterised, both experimentally and computationally, and highlight the availability of the phosphorus lone pair for coordination. This is confirmed by demonstrating that neutral azophosphines can act as ligands in Ru complexes, and can coordinate as monodentate or bidentate ligands in a controlled manner, in contrast to their nitrogen analogues. [ABSTRACT FROM AUTHOR]

Triazaphospholes are potential polydentate ligands due to the presence of both phosphorus and nitrogen donor atoms within the aromatic 5‐membered heterocycle. The incorporation of an additional pyridyl‐substituent opens up the possibility of a post‐synthesis modification via chemoselective and also stepwise alkylation exclusively of the nitrogen atoms. This can be controlled by the choice and by the stoichiometry of the electrophile and allows the targeted synthesis of a variety of novel mono‐ and dicationic ligands. Reaction with Cu(I)‐halides causes the formation of cuprates of the type [CuXn](n−1)−, which enables coordination of the π‐acidic phosphorus donor to the negatively charged metal core, which is favored over the coordination by a strongly σ‐donating nitrogen atom. The use of cationic triazaphosphole derivatives can be used as a strategy to enforce the coordination of the ligand to an electron rich metal solely via the phosphorus atom. However, there is a subtle balance between the formation of either coordination polymers or dimeric structures, as the substitution pattern on the heterocycle and the nature of the halide have a large influence on the coordination motifs formed. [ABSTRACT FROM AUTHOR]

While metal‐mediated self‐assembly is a popular technique to construct discrete nanosized objects, highly symmetric structures, built from one type of ligand at a time, are dominating reported systems. The tailored integration of a set of different ligands requires sophisticated approaches to avoid narcissistic separation or formation of statistical mixtures. Here, we demonstrate how the combination of three structure‐guiding effects (metal‐templated macrocyclization, additional bridging ligands and shape‐complementarity) based on Co(III)salphen metal nodes allows for a rational and high‐yielding synthesis of structurally complex, lantern‐shaped cages with up to four differentiable bridges. Three new heteroleptic coordination cages based on dinuclear Co(III)salphen macrocycles were synthesized in a one‐pot reaction approach and fully characterized, including single crystal X‐ray analyses. One cage groups two of the same ligands, another two different ligands around a symmetric Co2‐bis‐salphen ring. In the most complex structure, this ring is unsymmetric, rendering all four connections between the two metal centers distinguishable. While heteroleptic assembly around Pd(II) nodes has been shown to be dynamic, beneficial for cage‐to‐cage transformations, assembly cascades and adaptive systems, the herein introduced cages based on kinetically more inert Co(III)salphen will be advantageous for applications in enzyme‐like catalysis and molecular machinery that require enhanced structural and chemical stability. [ABSTRACT FROM AUTHOR]

Metal complexes with multidentate ligands are frequently used as model compounds to shed light on the (bio)‐inorganic chemistry of H2S. Zinc complexes bearing salen‐type ONNO ligands with different bridging groups are particularly relevant in this respect. Here, we describe the use of zinc complexes with the sulfur‐analogues of the ONNO ligands with the S‐donors replacing either the neutral nitrogen donors or the anionic oxygen atoms of the classical salen ligands. In addition, we studied a hexadentate cyclic ligand, with four neutral sulfur atoms and two anionic oxygens. Having two coordinative pockets this ligand is able to form a bimetallic zinc complex. We report how the different coordinative environments of the explored ligands influence the stability of the zinc complexes and their abilities to form the related hydrosulfide species. [ABSTRACT FROM AUTHOR]

In this report, a Cu(II) complex Cu‐L4 containing a new tetradentate benzotriazole‐appended bipyridine ligand was synthesized and characterized fully via spectroscopic and crystallographic techniques. The crystal structure of the complex revealed that the ligand is bound to copper in a tetradentate fashion in a plane and the axial positions are occupied by an anion and a solvent molecule, resulting in a distorted octahedral geometry of the complex in solid‐state. This air‐stable complex was utilized as homogeneous precatalyst for the synthesis of several propargylamine derivatives by 3‐component A3 coupling reactions of aldehydes, amines, and alkynes under aerial atmosphere. [ABSTRACT FROM AUTHOR]

A complex of the natural flavonoid kaempferol with zinc (Kam-Zn) was synthesized, and its physicochemical properties were investigated using spectroscopic methods such as Fourier transform infrared spectroscopy (FT-IR), ultraviolet–visible (UV-Vis) spectroscopy and theoretical chemistry. Biological studies were conducted to evaluate the cytotoxic and antiproliferative effects of these complexes on MCF-7 breast cancer cells. Treatment with Kam 100 µM (84.86 ± 7.79%; 64.37 ± 8.24%) and Kam-Zn 100 µM (91.87 ± 3.80%; 87.04 ± 13.0%) showed no significant difference in proliferation between 16 h and 32 h, with the gap width remaining stable. Both Kam-Zn 100 μM and 200 μM demonstrated effective antiproliferative and cytotoxic activity, significantly decreasing cell viability and causing cell death and morphology changes. Antioxidant assays revealed that Kam (IC50 = 5.63 ± 0.06) exhibited higher antioxidant potential compared to Kam-Zn (IC50 = 6.80 ± 0.075), suggesting that zinc coordination impacts the flavonoid's radical scavenging activity by the coordination of metal ion to hydroxyl groups. Computational studies revealed significant modifications in the electronic structure and properties of Kam upon forming 1:1 complexes with Zn2+ ions. Spectroscopy analyses confirmed structural changes, highlighting shifts in absorption peaks and alterations in functional group vibrations indicative of metal–ligand interactions. FT-IR and UV-Vis spectra analysis suggested that Zn coordinates with the 3-OH and 4C=O groups of ligand. These findings suggest that the Kam-Zn complex exhibits interesting antiproliferative, cytotoxic and modified antioxidant effects on MCF-7 cells, providing valuable insights into their structural and anticancer properties. [ABSTRACT FROM AUTHOR]

The synthesis and structural characterization of three families of coordination complexes synthesized from 4′‐phenyl‐2,2′:6′,2′′‐terpyridine (8, Ph‐TPY), 4′‐(4‐chlorophenyl)‐2,2′:6′,2′′‐terpyridine (9, ClPh‐TPY) and 4′‐(4‐methoxyphenyl)‐2,2′:6′,2′′‐terpyridine (10, MeOPh‐TPY) ligands with the divalent metals Co2+, Fe2+, Mn2+ and Ni2+ are reported. The compounds were synthesized from a 1:2 mixture of the metal and ligand, resulting in a series of complexes with the general formula [M(R‐TPY)2](ClO4)2 (where M = Co2+, Fe2+, Mn2+ and Ni2+, and R‐TPY = Ph‐TPY, ClPh‐TPY and MeOPh‐TPY). The general formula and structural and supramolecular features were determinated by single‐crystal X‐ray diffraction for bis(4′‐phenyl‐2,2′:6′,2′′‐terpyridine)nickel(II) bis(perchlorate), [Ni(C21H15N3)2](ClO4)2 or [Ni(Ph‐TPY)2](ClO4)2, bis[4′‐(4‐methoxyphenyl)‐2,2′:6′,2′′‐terpyridine]manganese(II) bis(perchlorate), [Mn(C22H17N3O)2](ClO4)2 or [Mn(MeOPh‐TPY)2](ClO4)2, and bis(4′‐phenyl‐2,2′:6′,2′′‐terpyridine)manganese(II) bis(perchlorate), [Mn(C21H15N3)2](ClO4)2 or [Mn(Ph‐TPY)2](ClO4)2. In all three cases, the complexes present distorted octahedral coordination polyhedra and the crystal packing is determined mainly by weak C—H...π interactions. All the compounds (except for the Ni derivatives, for which FT–IR, UV–Vis and thermal analysis are reported) were fully characterized by spectroscopic (FT–IR, UV–Vis and NMR spectroscopy) and thermal (TGA–DSC, thermogravimetric analysis–differential scanning calorimetry) methods. [ABSTRACT FROM AUTHOR]

Transition metal complexes have historically played a pivotal role in creating vibrant pigments utilized across artistic mediums such as ceramics, paintings, and glass mosaics. Despite their extensive historical use, our understanding of the mechanisms governing transition metal complex behavior has predominantly emerged in recent times, leaving numerous aspects of this process ripe for exploration. These complexes exhibit striking color variations under diverse conditions when employed in pigment formulations. This review utilizes a bottom-up scientific approach, spanning from microscopic to macroscopic scales, to unravel the molecular origins of the colors generated by transition metal complexes in pigments and ceramic glazes. Advanced spectroscopy techniques and computational chemistry play pivotal roles in this endeavor, highlighting the significance of understanding and utilizing analytical data effectively, with careful consideration of each technique's specific application. Furthermore, this review investigates the influence of processing conditions on color variations, providing valuable insights for artists and manufacturers aiming to enhance the precision and quality of their creations while mitigating environmental impact. [ABSTRACT FROM AUTHOR]

7Li nuclear magnetic resonance (NMR) spectroscopy is an ideal tool to study hierarchically assembled helicates of the form Li[Li3L6Ti2]. Internally bound and external lithium ions can be well distinguished by solution‐ or solid‐state NMR spectroscopy and dimerization constants of the monomer/dimer equilibrium can be easily determined in solution. Averaged dimerization constants can be estimated in case of statistical mixtures of helicates formed from mixtures of ligands. [ABSTRACT FROM AUTHOR]

The discovery that cyclic (ArO)2PF can support Rh-catalysts for hydroformylation with significant advantages in tuning regioselectivity transformed the study of metal complexes of monofluorophos ligands from one of primarily academic interest to one with potentially important applications in catalysis. In this review, the syntheses of monofluorophosphites, (RO)2PF, and monofluorophosphines, R2PF, are discussed and the factors that control the kinetic stability of these ligands to hydrolysis and disproportionation are set out. A survey of the coordination chemistry of these two classes of monofluorophos ligands with d-block metals is presented, emphasising the bonding of the fluorophos to d-block metals, predominantly in low oxidation states. The application of monofluorophos ligands in homogeneous catalysis (especially hydroformylation and hydrocyanation) is discussed, and it is argued that there is great potential for monofluorophos complexes in future catalytic applications. [ABSTRACT FROM AUTHOR]

Coordination compounds, like iron(II) triazole complexes, exhibit spin crossover (SCO) behavior at around room temperature. Therefore, they are interesting for a variety of possible applications, and it is convenient to integrate them into polymers. Due to a reduction of the iron content and thus also 57Fe content in the sample through integration in polymers, Mössbauer measurements are only possible with greater difficulty or very long measurement times without expensive enrichment of the samples with 57Fe. So, other ways of improving the Mössbauer signal for these composite materials are necessary. Therefore, we pressed these composite materials to improve the Mössbauer spectra. In this study, we synthesized an iron(II) triazole spin crossover complex and an electrospun polymer complex composite nanofiber material including the same complex. For both products, Mössbauer measurements were performed at room temperature before and after using a press to show that the complex composite is not harmed through pressing. We investigate the influence of the pressing impact on the Mössbauer measurements in the context of measurement statistics and the measured signals. We show that pressing is not connected to any changes in the sample regarding the spin and oxidation state. We present that pressing improves the statistics of the Mössbauer measurements significantly. Furthermore, we use SEM measurements and PXRD to investigate whether or not the obtained fiber mats are destroyed in the pressing process. [ABSTRACT FROM AUTHOR]

The synthesis of a family of chiral and enantiomerically pure pyridyl‐diamide (pda) ligands that upon complexation with europium [Eu(CF3SO3)3] result in chiral complexes with metal centered luminescence is reported; the sets of enantiomers giving rise to both circular dichroism (CD) and circularly polarized luminescence (CPL) signatures. The solid‐state structures of these chiral metallosupramolecular systems are determined using X‐ray diffraction showing that the ligand chirality is transferred from solution to the solid state. This optically favorable helical packing arrangement is confirmed by recording the CPL spectra from the crystalline assembly by using steady state and enantioselective differential chiral contrast (EDCC) CPL Laser Scanning Confocal Microscopy (CPL‐LSCM) where the two enantiomers can be clearly distinguished. [ABSTRACT FROM AUTHOR]

We studied electrochemical behavior of UVO2+/UVIO22+ in non‐aqueous liquid electrolytes to clarify what is required to attain its reversibility for utilizing depleted U in a redox‐flow battery. To transfer knowledge from former pyrochemical systems in high temperature molten salts, 1‐ethyl‐3‐methylimidazolium bis(trifluoromethyl)sulfonylamide ([emim]Tf2N) ionic liquid was employed here. As a result, a reversible redox reaction of the UVO2+/UVIO22+ was successfully observed on a glassy carbon working electrode under presence of Cl− in [emim]Tf2N, where [UVIO2Cl4]2−+e−=[UVO2Cl4]3− occurs after stabilization of both U oxidation states by the Cl− coordination. The observed electrochemical responses are rather sensitive to an electrode material, so that cyclic voltammograms on a Pt working electrode were actually irreversible. To improve diffusivity of solutes, viscosity (η) of [emim]Tf2N diluted with an auxiliary molecular solvent, N,N‐dimethylformamide (DMF), was examined under absence and presence of Cl−. When the mole fraction of DMF (xDMF) is 0.769, η of the mixture becomes sufficiently low to be utilized as a liquid electrolyte. Finally, we have succeeded in demonstrating a reversible redox reaction of [UVIO2Cl4]2−+e−=[UVO2Cl4]3− in the [emim]Tf2N‐DMF (50 : 50 v/v, xDMF=0.769) liquid electrolyte containing [Cl−]=0.519 M, where η=6.2 mPa ⋅ s. [ABSTRACT FROM AUTHOR]

Closed‐chain oligopyrroles such as porphyrins or corroles have been well‐established in literature and experience a steadily strong interest by several fields of science. However, their open‐chain derivatives are comparatively underrepresented, despite their intriguing properties and promising applications. Here, we aim to review typical synthetic routes, as well as point towards several emergent properties, marking them as interesting candidates for various fields of study. The review focuses on two traditional methods (each starting from highly symmetric metalloporphyrins) and then expands its scope towards more recent variations before moving on to more exotic and recent highlights that have yet to be included into the canon. Key chemical reactivities (ring closure, substitution and fragmentation) are then followed by notable physicochemical properties, placing special emphasis on potential uses in molecular electronics and sensors. [ABSTRACT FROM AUTHOR]