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Oxygen reduction reaction (ORR) is Achilles' heel of zinc‐air battery. The ideal electrocatalyst for ORR should combine both high activity and high stability. In order to achieve this goal, a new N, S co‐doped carbon coated Fe3N nanoparticles electrocatalyst with redistributed charge was designed and synthesized. The doping of S elements destroyed the ordered structure of carbon matrix, which cooperated with Fe3N nanoparticles to cause charge redistribution of carbon atoms. Furthermore, the carbon shell protected Fe3N from corrosion during the electrocatalytic process. Fe3N/NSC electrocatalyst showed excellent ORR property with E1/2=0.86 V, and the zinc‐air battery assembled based on it could run stably for more than 650 hours. This work provides a strategy to regulate the redistributed charge of carbon atoms to boost its electrocatalytic activity and stability together. [ABSTRACT FROM AUTHOR]

Utilization of metal–organic frameworks (MOFs) as electrodes for energy storage/conversion is challenging because of the low chemical stability and poor electrical conductivity of MOFs in electrolytes. A nanoscale MOF, Co0.24Ni0.76‐bpa‐200, possessing ultrahigh stability with uncommon semiconductor behavior (σ=4.2×10−3 S m−1) was fabricated. The MOF comprises a robust hydrophobic paddlewheel and an optimized Co/Ni ratio, with consequent control over MOF size and the degree of conjugation of the coligand. A DFT study revealed that appropriate Ni2+ doping reduces the activation energy of the system, thus providing a higher carrier concentration, and the strongly delocalized N‐donor ligand notably increases the metal–ligand orbital overlap to achieve efficient charge migration, leading to continuous through‐bond (‐CoNi‐N‐CoNi‐)∞ conduction paths. These structural features endow the MOF with a good cycling stability of 86.5 % (10 000 cycles) and a high specific capacitance of 1927.14 F g−1 among pristine MOF‐based electrodes. [ABSTRACT FROM AUTHOR]

The precise synthesis of electrode materials that integrate highly redox‐active transition‐metal oxide with conductive transition‐metal sulfide has always been a challenge, due to the extraordinarily robust coordination affinity of sulfur for transition metals. Herein, through controlling the calcined sulfurization temperature to stimulate the activity of oxygen to compete with sulfur, an integrated Co1−xS/CoFe2O4@rGO nanoflower is fabricated in the range of 780–830 °C by employing well‐designed Co0.8Fe0.2‐MOF‐74@rGO as precursor. The hierarchical‐pore structure evolved from the bimetallic MOF@rGO provides a suitable electrolyte environment to promote fast Faradaic reactions, which endows Co1−xS/CoFe2O4@rGO with a high specific capacity of 2202 F g−1 and remarkable cycling stability (90% after 20 000 cycles), superior to those of the most well‐known metal‐organic framework (MOF) derived systems. The assembled Co1−xS/CoFe2O4@rGO//AC asymmetric supercapacitor shows an outstanding energy density up to 61.5 Wh kg−1 at a power density of 700 W kg−1. A combined experimental and density functional theory calculation demonstrates that the merged Co1−xS/CoFe2O4 interface with optimized electronic structure facilitates electron transfer pathways and realizes the effective synergy of high redox activity from CoFe2O4 and good conductivity from Co1−xS, leading to the excellent electrochemical performance of the material. Additionally, the formation mechanisms of the temperature‐controlled different phases are systematically investigated. [ABSTRACT FROM AUTHOR]

The first isolable silylene–germylene complex 5 was assembled by a salt metathesis reaction between the germylene anion 3 and the N‐heterocyclic chlorosilylene 4, and structurally characterized. The central structure of 5 demonstrates a remarkable gauche‐bent geometry with the silylene and germylene units, which are interconnected by a Si−Ge bond with a length of 2.4498(9) Å. This value is not only perceptibly longer than the distances known in doubly bonded germasilenes, and also slightly longer than those in germylsilanes. The DFT calculations on 5 confirmed a nearly nonpolar SiI−GeI single‐bond nature and its bonding orbital, as well as the aromaticity of the C3NGe‐rings in 3 and 5. The latter increases the molecular stability of 3 and 5, and makes the preparation of silylene–germylene complex 5 a reality. [ABSTRACT FROM AUTHOR]

A rigid β‐diketiminate ligand was used to synthesize a cationic hydroxyborane and an anionic oxoborane. The anionic oxoborane has a negatively charged oxo‐group, which possesses a 1.301(3) Å B–O double bond and interacts with the hydrogen bond of an imidazolium cation. Theoretical calculations successfully illustrate the unsaturated nature of the B–O bond and the stability of the conjugated C3N2B‐ring in the oxoborane. The isolation of the new oxoborane compound offers promising approaches to unsaturated boron species. [ABSTRACT FROM AUTHOR]

A family of four mononuclear DyIII β‐diketonate complexes with formulas [Dy(tmhd)3(Br2‐bpy) (1), [Dy(tmhd)3(Br‐bpy)] (2), [Dy(tmhd)3(dppz)] (3), and [Dy(tmhd)3(mcdpq)] (4) (tmhd=2,2,6,6‐tetramethyl‐3,5‐heptanedione, Br2‐bpy=5,5′‐dibromo‐2,2′‐bipyridine, Br‐bpy=5‐bromo‐2,2′‐bipyridine, dppz=dipyrido [3,2‐a:2′,3′‐c]phenazine, mcdpq=2‐methoxyl‐3‐cyanodipyrido[3,2‐f:2,3′‐h]quinoxaline) were prepared by modifying the capping N‐donor coligands. DyIII centers in these complexes feature an N2O6 octacoordinate environment with distorted square‐antiprismatic D4d symmetry. Magnetic investigations evidenced single‐ion magnet behavior in all complexes with energy barriers Ueff of 42.10 (1), 61.47, (2), 77.53 (3), and 2.51 K (4) in the absence of static field, as well as 206.03 (1), 224.13 (2), 247.76 (3), and 49.70 K (4) under applied dc field (Hdc=1500 Oe for 1 and 2; Hdc=1200 Oe for 3 and 4). The different natures of the N‐donor ligands induce changes in both the coordination geometry and their intermolecular interactions, which severely impact their magnetic dynamics. The disparities in their magnetic behaviors and the uniaxial anisotropies are also explained and substantiated by theoretical calculations. Cap variations: A combination of electron‐donating β‐diketonate ligands and different capping N‐donor coligands led to a family of four mononuclear DyIII complexes exhibiting nearly identical D4d symmetry but differing magnetic dynamics, which were elucidated by a combination of magnetic investigations and ab initio calculations. [ABSTRACT FROM AUTHOR]

Taking advantage of the steric hindrance and charge-driving effects, four air-stable pentagonal bipyramidal mononuclear DyIII compounds were hydrothermally synthesized. With a tetradentate ligand, N, N′-bis(2-methylenepyridinyl)ethylenediamine (Bpen), invariably coordinates to DyIII in an equatorial plan, 1- 3 achieve an orderly transformation of the ligand field by sequentially replacing the remaining sites of the DyIII ion. Compound 4 possesses the same coordination atoms but a different peripheral coordination sphere with 3. Magnetic characterizations display that the compounds are field-induced single-ion magnets (SIM) with actually low barriers, even though 2 has both the same atoms and a similar geometry of the first sphere compared with [Dy(bbpen)Cl] ( 2′, H2bbpen= N, N′-bis(2-hydroxybenzyl)- N, N′-bis(2-methylpyridyl)ethylenediamin), a high-performance SIM previously reported. Detailed ab initio calculations have been employed to further elucidate the electronic and magnetic structure of the low-lying energy levels of compounds 1- 4 and 2′. The theoretical results indicate there is an apparent difference in the electronic structure for these compounds. The analysis on the electrostatic potential further demonstrates that although the pentagonal bipyramidal D5 h is one of the ideal configurations expected, the electron density of the donor atoms from the different hybridizations and other functional groups, outside the first sphere, should also be considered in the rational design of promising molecular magnets. [ABSTRACT FROM AUTHOR]

A new solvent-free energetic MOF, [Pb(HBTI)] n ( 1) (H3BTI=4,5-bis(1 H-tetrazole)-1 H-imidazole), has been synthesized under hydrothermal and acidic conditions. It was characterized by elemental analysis, IR, thermogravimetric, differential scanning calorimetry (DSC) and SEM. Single crystal X-ray diffraction analysis revealed that 1 features a rigid 3D framework architecture free of solvent molecules. Thermal analysis demonstrated that the thermostability of 1 was up to 325 °C. Non-isothermal kinetic and apparent thermodynamic parameters of exothermic decomposition process of 1 were determined by Kissinger's and Ozawa's methods. Through oxygen-bomb combustion calorimetry, the standard molar enthalpy of formation of 1 was determined. The calculated detonation properties (heat of detonation, detonation velocity and detonation pressure) and sensitivity tests of 1 were carried out. In addition, 1 was explored as combustion promoter to accelerate the thermal decompositions of ammonium perchlorate (AP) by differential scanning calorimetry. Experimental results indicated that 1 possesses potential application prospects in the field of explosives and propellants. [ABSTRACT FROM AUTHOR]

Three dinuclear coordination compounds, [Ln2(Hhms)2(NO3)4]·MeCN [Ln = Dy (1) and Er (2)] and [Dy2(Hhms)2(NO3)2(H2O)3]·(NO3)2·MeCN·(H2O)2 (3), have been isolated bearing the asymmetric Schiff-base ligand 1-(2-hydroxy-3-methoxybenzylidene)semicarbazide (H2hms). The potentially tetradentate ONOO-donor ligand shows considerable metal-ion-selective phenoxo bridging in 1–3. Compounds 1 and 2 display a hula-hoop-like coordination geometry, whereas this geometry is broken by an additional µ2-OH2 bridge in compound 3. The structural discrepancies induced by the different bridging modes in 1 and 3 affect the magnetism. Compound 1 exhibits slow relaxation of the magnetization, which suggests single-molecule magnet (SMM) behavior, whereas no out-of-phase alternating-current signal was observed for 3. Meanwhile, compared with a previously reported Dy2 compound, compound 1 has the same coordination sphere but exhibits different magnetic properties, which has been attributed to differences in the ligand backbone. Fine-tuning of the ligand field is dominated by µ-O bridges and by the extent of conjugation in the backbone of the ligand, which affects the SMM/non-SMM behavior. [ABSTRACT FROM AUTHOR]

A new energetic MOF, [Cu2(to)(dns)(H2O)] n ( 1; H2to = 1,2,4-triazol-5-one, H2dns = 3,5-dinitrosalicylic acid), has been synthesized and structurally characterized. Single-crystal X-ray diffraction analysis revealed that 1 possesses a compact 3D architecture. Noteworthy, the two oxygen atoms of one nitro coordinate to two CuII ions in a syn-anti mode, which decreases its sensitivity but has no influence on its explosive properties. Based on the results of thermogravimetric and differential scanning calorimetry analyses, MOF 1 displays a rapid thermal decomposition process and superior thermostability. The non-isothermal kinetics of the exothermic process of 1 were studied by the methods of Kissinger and Ozawa. The sensitivity tests and calculated detonation properties show that 1 has the potential to be used in green explosives. [ABSTRACT FROM AUTHOR]

3-Oxy-furoxanate is immobilized in a heterometallic energetic metal-organic framework (MOFs). Two furoxan-based MOFs ([Ag2K4(BDOFO)(BDFO)2(H2O)6] n, [K2(BDFO)] n) and a salt ([(BDFO2−)(NH2NH3+)2(H2O)] n (BDOFO2−=4,5-bis(dinitromethyl)-3-oxy-furoxanate, BDFO2−=4,5-bis(dinitromethyl)-furoxanate) are synthesized and their energetic performance evaluated. This study outlines the systematic investigation of detonation performance of 3-oxy-furoxan and its derivatives. [ABSTRACT FROM AUTHOR]

Five lanthanide coordination polymers ( Ln-CPs) based on pyridine-dicarboxylate and lanthanide metal ions were synthesized and characterized, namely [Sm(pydc)(Hpydc)(H2O)5] ·4H2O ( 1) (H2pydc = 2, 5-pyridine-dicarboxylic acid), [Ho(pydc)(Hpydc)(H2O)3] n ·4nH2O ( 2), [Ce(pydc)(bdc)(H2O)] n ( 3) (H2bdc = 1, 4-benzenedicarboxylic acid), [Nd2(dipic)3(H2O)3] n ( 4), and [Pr2Ag2(dipic)4(H2O)5] n ·5nH2O ( 5) (H2dipic = 3, 5-pyridine-dicarboxylic acid). Complexes 1 and 2 display mononuclear structure and 1D zigzag chains, respectively. In complex 3, the CeIII ions are connected through pydc2- and bdc2- ligands to generate an intricate 3D architecture. Complex 4 is constructed through dinuclear {Nd2} SBUs and oxygen bridging from carboxyl groups of dipic2- to generate a 3D framework. In 5, PrIII ions and AgI ions are assembled into a 2D heterometallic layer, in which the rare Ag ···Ag weak interactions are observed. Furthermore, the solid state luminescent properties of 1- 4 were measured and discussed. [ABSTRACT FROM AUTHOR]

Reaction of Co(II) with the nitrogen-rich ligand N, N-bis(1 H-tetrazole-5-yl)-amine (H2bta) leads to a mixed-valence, 3D, porous, metal-organic framework (MOF)-based, energetic material with the nitrogen content of 51.78%, [Co9(bta)10(Hbta)2(H2O)10] n⋅(22 H2O) n ( 1). Compound 1 was thermohydrated to produce a new, stable, energetic material with the nitrogen content of 59.85% and heat of denotation of 4.537 kcal cm−3, [Co9(bta)10(Hbta)2(H2O)10] n ( 2). Sensitivity tests show that 2 is more sensitivity to external stimuli than 1, reflecting guest-dependent energy and sensitivity of 3D, MOF-based, energetic materials. Less-sensitive 1 can be regarded as a more safe form for storage and transformation to sensitive 2. [ABSTRACT FROM AUTHOR]

The asymmetric unit of the title compound, [CuCl(C(12)H(8)N(2))(2)]·[CuCl(2)], contains two complex Cu(II) cations and two cuprate(I) anions. The Cu(II) atom is coordinated by two phenanthroline (phen) mol-ecules and one chloride anion in a distorted trigonal-bipyramidal geometry. The Cu(II) complex cations form layers through π-π stacking [interplanar distance = 3.481 (2) Å]. The dichloridocuprate(I) anions are located between the layers, forming a sandwich-like structure.