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This study uses first-principles calculations to investigate the asymmetric Zr2CO/VSe2 heterostructure for hydrogen evolution reaction (HER) applications, focusing on its interlayer interactions, electronic structures, and HER performance across six stacking angles. Our findings demonstrate remarkable structural stability, characterized by interlayer distances of 2.1 Å to 2.7 Å and binding energies from −150.521 to −257.939 meV Å−2. Band structure analyses highlight the heterostructures' exceptional conductivity, essential for catalytic efficiency. Additionally, charge density difference calculations reveal significant charge transfer and redistribution at the interface, providing insights into the interlayer interactions and their influence on catalytic activity. Notably, the Gibbs free energy of hydrogen adsorption (ΔGH*) remains within ±0.1 eV across all configurations, indicating superior HER activity. Further analysis shows that the work function (Φ) serves as a critical electronic structure descriptor, influencing HER performance. The relationship between work function and ΔGH* across different interlayer distances underscores the predictive value of the work function for HER activity. These insights provide a theoretical foundation for developing advanced and effective non-noble metal HER catalysts, paving the way for innovations in sustainable energy technologies. [ABSTRACT FROM AUTHOR]

Multi-functionalised nano-platforms based on persistent-luminescence nanoparticles (PLNPs) have attracted considerable attention for biomedical applications owing to their lack of background noise and suitability for in vivo imaging without the need for in situ excitation. However, nano-platforms based on PLNPs for continuous photodynamic therapy (PDT) are currently lacking. Herein, we report a nano-platform (LiGa4.99O8:Cr0.01/IrO2, LGO:Cr/IrO2) prepared using PLNPs (LiGa4.99O8:Cr0.01, LGO:Cr) covalently bonded with iridium oxide nanoparticles (IrO2 NPs), producing near-infrared (NIR) persistent luminescence, "afterglow" PDT and photo-thermal therapy (PTT) effects. The LGO:Cr/IrO2 not only exhibits NIR-persistent luminescence at 719 nm and a PTT effect under 808 nm irradiation but also a continuous "afterglow" PDT effect without the need for in situ excitation owing to persistent energy transfer from LGO:Cr to the IrO2 NPs, in turn generating reactive oxygen species (ROS). This multi-functional nano-platform is expected to further promote the application of PLNPs in tumour treatment. [ABSTRACT FROM AUTHOR]

Perovskite quantum dots (QDs) have been identified as propitious candidates for next-generation high-definition displays owing to their excellent photoelectric properties, such as size-tuneable optical bandgaps, narrow emission and extraordinary charge-transport properties. However, during the purification process of QD synthesis, QDs are always accompanied by problems of ligand falling off and mismatches of Pb atoms, which will decrease the photoluminescence quantum yield (PLQY) of QDs and affect the device performance adversely. Here, a simple method by doping alkali halide CaCl2 as a co-precursor is proposed to improve the optoelectronic properties of CsPbI3 QDs. Excess halide anions could provide a halide-rich environment and efficiently passivate surface defect states of CsPbI3 QDs. Meanwhile, introducing alkali metal ions could reduce nonradiative decay rates by suppressing the defects originating from Pb atoms with insufficient coordination in CsPbI3 QDs. These results will stimulate research on LEDs for next-generation high-definition display technologies. [ABSTRACT FROM AUTHOR]

The removal of carbon dioxide (CO2) from acetylene (C2H2) is not only industrially important for acetylene purification but also scientifically challenging owing to their high similarities in physical properties and molecular sizes. Multi-walled and ultramicroporous metal–organic frameworks (MOFs) can provide multiple specific interactions with C2H2 supplied to form a cooperative effect for efficient separation properties. Herein, we report a new strategy involving the extension of vertices to create an infinite multi-walled MOF (In-TATB) from 2,4,6-tris(4-carboxyphenyl)-1,3,5-triazine (H3TATB) and In(III) ions. Two 3D frameworks built from In(III) chains and TATB3− molecules interpenetrate through strong π–π interactions between triazine rings. Taking advantage of the confined ultramicroporous space (3.8 Å × 4.1 Å) and accessible sites of multiple walls, In-TATB shows a high adsorption enthalpy of C2H2 (36.6 kJ mol−1 at 298 K and low-coverage) and excellent separation of C2H2/CO2 mixtures with an IAST selectivity of 11.8 (at 298 K and 1 bar). More importantly, both dry and wet breakthrough results validated its exceptional separation performance for C2H2/CO2 mixtures, affording a high dynamic separation factor. This work provides a novel and powerful approach to address this extremely challenging gas separation in industry. [ABSTRACT FROM AUTHOR]

A new family of low-coordinate mononuclear DyIII single-molecule magnets [(TrapenTMS)Dy(LB)] (Trapen = tris(2-aminobenzyl)amine; TMS = SiMe3; LB = THF 1, pyridine 2, ONMe33) has been synthesized and structurally characterized by single crystal X-ray diffraction. The five-coordinate DyIII ions exhibit distorted triangular bipyramidal geometries, among the different neutral ligands LB on the apex and the same TrapenTMS ligand, making the pyramid base of the trigonal bipyramid. Magnetic data analysis reveals that 1–3 are characteristic of SMM behaviors without a dc field, accompanying an unambiguous quantum tunneling of magnetization. Under an extra dc field of 500 Oe, field-induced slow magnetic relaxation behaviors occur with Raman and/or QTM processes. Ab initio calculations were also performed to rationalize the observed discrepancy in the magnetic behaviors, and the result illustrates that the SMM behavior could be effectively manipulated by the axial symmetry of the triangular bipyramidal DyIII motifs. [ABSTRACT FROM AUTHOR]

Peripheral nerve injury (PNI) results in persistent pain, a burning sensation, tingling, or complete loss of sensation. Treating large nerve defects is a major challenge, and the use of autologous nerve grafts (ANGs) cannot overcome this challenge. Hence, substitutes for ANGs that can serve as artificial nerve fibers are urgently needed in the clinical treatment of PNI. To develop such substitutes, we genetically engineered a virus nanofiber (M13 phage) that displays a high density of RGD peptide on its sidewall, producing an RGD-displaying phage (R-phage). In the presence of neural stem cells (NSCs), the resultant negatively charged R-phage nanofibers were electrostatically bound to a complex (with a net positive charge) of negatively charged fibrin and positively charged polyethyleneimine (PEI). The biocompatible injectable fibrin gel (FG) was integrated with R-phage and seeded with NSCs, forming a hydrogel termed R-phage/FG, which is further extruded through a syringe to form a fiber. The developed fiber-shaped hydrogel exhibited the desired excellent physical–chemical properties, and controllable and appropriate mechanical properties (170–240 kPa) similar to native nerve. The R-phage/FG not only promoted NSC adhesion, infiltration, and proliferation, but also induced efficient preferential differentiation of NSCs into neurons in the hydrogels in a non-differentiating medium within only 4 days. After the NSC-seeded R-phage/FG was injected into the long-gap (10 mm) defect of a rat's sciatic nerve, a solid neuron-rich hydrogel fiber was formed as an artificial nerve fiber graft that stimulated neurogenesis in the transplanted area within 60 days for nerve regeneration. These results suggest that the R-phage/FG fiber represents a potential substitute ANG for repairing large nerve injuries. This work demonstrates a new phage-based biomaterial that can be used as a graft for treating PNI through neurogenesis. [ABSTRACT FROM AUTHOR]

Four air-stable mononuclear Co(II) complexes, with the formulas [Co(dapbh)(H2O)(CH3OH)] (1), [Co(Hdapbh)(N3)(CH3OH)]·(CH3OH) (2), [Co(H2aapbh)(CH3OH)2]·(NO3)2 (3) and [Co(H2bapbh)(H2O)(NO3)]·(NO3) (4), have been synthesized and structurally characterized by single crystal X-ray diffraction. In all of the complexes, the Co(II) centers constrained by the rigid pentadentate ligand H2LR with two protonable hydrogens adopt a heptacoordinated pentagonal-bipyramidal geometry. The combined analyses of magnetic data and ab initio calculations unveil large easy-plane magnetic anisotropies for these complexes (D = +37.338, +37.273, +41.138 and +41.139 cm−1 for 1–4, respectively), which indicate that the chemical alterations of the equatorial ligand and the ligand field strength in the axial positions synergistically fine-tune the magnitude of the D values. Magnetic investigations demonstrate the field-induced single-ion magnetic behavior in complexes 1, 2 and 4 with diverse energy barriers (Ueff) of 12.25 for 1, 44.15 for 2 and 48.72 K for 4, corresponding to the geometrical distortion of the heptacoordinated Co(II) ion. That is, the greatest deviation from the ideal D5h symmetry in 4 is responsible for the highest barrier. [ABSTRACT FROM AUTHOR]

Based on a β-diketiminate ligand, an iron(III) tetrahedral high-spin complex, [LFeIII(Cl)2] (1), and an iron(II) high-spin triangular planar complex, [LFeIICl] (2), have been synthesized and structurally characterized. Also, complex 1 can be considered as a precursor to produce 2via a reduction process, with a concomitant change in its magnetic anisotropy. Combined experiments and ab initio calculations support the observation of field-induced single-ion magnet (SIM) behaviour for 2 with an effective spin-reversal energy barrier of Ueff = 40.02 K, as a direct consequence of the large intrinsic magnetic anisotropy (easy axis) arising from out-of-state spin-orbit coupling in the trigonal planar FeII complex. Noteworthy butterfly hysteresis loops were observed from 2 up to 8 K, which represents the first case in Fe(II) complexes. [ABSTRACT FROM AUTHOR]

Two air-stable Co(III)–Co(II) mixed-valence complexes of molecular formulas [CoIICoIII(L)(DMAP)3(CH3COO)]·H2O·CH3OH (1) and [CoIICoIII(L)(4-Pyrrol)3 (CH3COO)]·0.5CH2Cl2 (2) (H4L = 1,3-bis-(5-methyl pyrazole-3-carboxamide) propane; DMAP = 4-dimethylaminopyridine; and 4-Pyrrol = 4-pyrrolidinopyridine) were synthesized and characterized by single-crystal X-ray crystallography, high-field electron paramagnetic resonance (HFEPR) spectroscopy, and magnetic measurements. Both complexes possess one five-coordinated paramagnetic Co(II) ion and one six-coordinated Co(III) ion with octahedral geometry. Direct-current magnetic susceptibility and magnetization measurements show the easy-axis magnetic anisotropy that is also confirmed by low-temperature HFEPR measurements and theoretical calculations. Frequency- and temperature-dependent alternating-current magnetic susceptibility measurements reveal their field-assisted slow magnetic relaxation, which is a characteristic behavior of single-molecule magnets (SMMs), caused by the individual Co(II) ion. The effective energy barrier of complex 1 (49.2 cm−1) is significantly higher than those of the other dinuclear Co(III)–Co(II) SMMs. This work hence presents the first instance of the dinuclear Co(III)–Co(II) single-molecule magnets with a five-coordinated environment around the Co(II) ion. [ABSTRACT FROM AUTHOR]

Two β-Diketiminate cobalt(II) compounds of formula [LCo(μ-Cl)]2·2C6H14 (1) and [LCoClPy]·0.5C7H8·0.5C6H14 (2) (L = [PhC-(PhCN-Dip)2]−, Dip = 2,6-iPr2C6H3) have been synthesized and structurally characterized by single crystal X-ray diffraction. Compound 1 exhibits a dinuclear structure, whereas 2 is a mononuclear structure having a pyridine ligand. The tetra-coordinate CoII centers in both compounds show distorted tetrahedral geometry configuration. Magnetic measurements reveal that only 2 exhibits field-induced slow relaxation of magnetization with an effective spin-reversal energy barrier of 16.27 K, though large easy-axis magnetic anisotropies for both compounds are unveiled by the analysis of ab initio calculations. Dimeric Co–Co units in 1 indicate intramolecular antiferromagnetic interaction. Compared to individual CoII fragment of 1, the first excited quartet state of 2 is strongly destabilized, leading to a smaller unquenched orbital angular momentum and D value. The comprehensive factors above are responsible for the difference in the magnetic behavior between 1 and 2. [ABSTRACT FROM AUTHOR]

While the interest in single-molecule magnets (SMMs) lies in their potential applications in information storage and quantum computing, the switching of their slow magnetic relaxation associated with dynamic crystal-to-crystal transformation is insufficiently exploited. Herein, three pentagonal-bipyramidal (PBP) Dy(III) complexes, [Dy(Bcpen)(Cl)3] (1), [Dy(Bcpen)(OPhCl2NO2)3] (2) and [Dy(Bcpen)(OPhCl2NO2)3]·0.5CH3CN (2·CH3CN), are successfully assembled, and structurally and magnetically studied (Bcpen = N,N-bis(4-chloro-2-methylenepyridinyl) ethylenediamine and Cl2NO2PhOH = 2,6-dichloro-4-nitrophenol). The molecular characteristics and magnetic properties of complexes 2 and 2·CH3CN, constructed with the motivation of modulating a magnetic switch by external stimuli, are systematically explored. Dramatically, 2 and 2·CH3CN can mutually transform through reversible single-crystal-to-single-crystal (SCSC) conversion associated with the capture and release of guest CH3CN molecules, resulting in an infrequent on/off switching of PBP Dy(III) molecule-based magnets. Further measurements on the desolvated and resolvated samples, complexes 2-re and 2·CH3CN-re, confirm the fascinating transformation processes. The magneto-structural relationship has been rationally investigated and discussed with ab initio calculations as well. [ABSTRACT FROM AUTHOR]

The synthesis, characterization, crystal structure and detailed magnetic properties of a pyrazine (pyz) and azido (N3) bridged cobalt(II) compound of formula [Co(N3)2(pyz)] (1) are reported. Compound 1 shows a layered structure formed by Co(II) chains with double μ-N3(κN1,N1) bridges that are further connected by μ-(pyrazine-κN1,N4) bridges. The layers present weak van der Waals interactions between azido terminal groups. The magnetic properties show the presence of a metamagnetic behaviour in 1 with two critical fields of 200 and 400 mT at low temperatures. AC magnetic measurements show the presence of a long-range 2D ferromagnetic order at Tc ≈ 8.0–7.0 K for dc fields above 200 mT and a long-range 3D ferromagnetic order at Tc ≈ 4.5 K for dc fields above 400 mT. [ABSTRACT FROM AUTHOR]

The ever-growing antibiotic-resistant bacteria pose a huge threat to public health. Restoring the susceptibility of ineffective antibiotics by inorganic nanomaterials and combining the photothermal and antibiotic effects could be an optional strategy to combat this resistance. Here, cefotaxime (CTX) loaded tellurium nanoparticles (Te NPs) were fabricated to recover the antibacterial activity of the ineffective β-lactam antibiotic CTX against methicillin-resistant Staphylococcus aureus (MRSA) and at the same time perform photothermal therapy under light-emitting diode (LED) irradiation with a wavelength in the range of 420–480 nm. The combination of 50 μg mL−1 Te–CTX NPs with 5 min LED irradiation produced a 30.4 °C temperature increase and killed 99% of MRSA in vitro. In vivo evaluation in mice revealed that Te–CTX NPs and LED irradiation accelerated the healing of MRSA infected wounds and presented biosafety. Furthermore, this combination accelerated glutathione oxidation and resulted in the disruption of the antioxidant defence system of MRSA. Such a synergistic antibiotic and photothermal therapy provides an innovative way for the treatment of antibiotic-resistant bacterial infections. [ABSTRACT FROM AUTHOR]

Two novel dual-photosensitized stable complexes, namely [Eu(dpq)(BTFA)3] (1) and [Tb(dpq)(BTFA)3] (2), have been successfully assembled via a mixed ligand approach using dipyrido[3,2-d:2′,3′-f]quinoxaline (dpq) and 3-benzoyl-1,1,1-trifluoroacetone (BTFA). The crystallographic data reveal mononuclear lanthanide cores in both 1 and 2, in which each eight-coordinated Ln(III) ion is located in a slightly distorted dodecahedron (D2d). The room-temperature photoluminescence spectra of complexes 1 and 2 indicate that both BTFA and dpq can effectively sensitize Eu(III) and Tb(III) characteristic luminescence. Moreover, heterometallic Ln-complexes can be synthesized, leading to a new series of differently doped EuxTb1−x complexes. Luminescence experiments on them reveal dual-emission peaks of Eu3+ and Tb3+, which lead to a gradual change in the luminous colour between yellow-green, yellow, orange, orange-red and red upon increasing the Eu3+ content. On the basis of the intrinsic strong emission properties and nontoxic nature of complexes 1 and 2, we explore their potential application as cellular imaging agents. Fluorescence microscopy data suggest the cytosolic and nuclear localization of 1 and 2 in HeLa and MCF-7 cells. [ABSTRACT FROM AUTHOR]

pH-Dependent self-assembly and structural transformation have been observed in a series of porous In(III)-MOFs, H3O[In3(pta)4(OH)2]·10H2O (NXU-1), [In(pta)2]·C3H10N (NXU-2) and [In(pta)2]·C3H10N (NXU-3) (H2pta = 2-(4-pyridyl)-terephthalic acid). The structural diversities of NXU-1–3 reveal that the pH value of the reaction plays a key role in the assembly of In-MOFs. NXU-1 with excellent stability exhibits highly selective CO2 adsorption over CH4 as compared to NXU-2 and NXU-3, owing to the presence of abundant multiple active sites unveiled by theoretical calculations. [ABSTRACT FROM AUTHOR]

Anionic metal–organic frameworks (MOFs) are beginning to have a great impact in the field of absorption and separation of ionic organic molecules due to the enhanced electrostatic interactions between their anionic frameworks and counter-ionic guests. Herein, the rational design and synthesis of two mesoporous anionic MOFs, [Zn3(ITTC)3](Me2 NH2)3·3DMF·H2O (1) and [Cd2(ITTC)3](Me2NH2)5·2DMF (2), where H3ITTC = 4,4′,4′′-(1H-imidazole-2,4,5-triyl) tribenzoic acid, is reported. Structural analysis revealed that both materials are anionic MOFs with a 2-fold interpenetrating three dimensional (3D) framework. The cross sectional area of the open one-dimensional rectangular channels is 31.7 Å × 15.6 Å for 1, of which the architecture is indicative of an unprecedented (3,3,4,5)-connection topology. For 2, the diameter of the open one-dimensional regular hexagonal channel is about 34.1 Å, decorated with uncoordinated carboxyl O atoms, and the framework exhibits a (3,4)-connected fcu network. Due to their anionic frameworks and bulky pore window sizes, both MOFs can be employed for absorbing and separating the cationic organic dye methylene blue (MB). The results reveal that both MOFs have better dye adsorption selectivity for MB, than for MO and SDI, because of charge and size-matching effects, enabling them to be potential candidates for use in environmental cleaning. By comparison, 2 presents superior selectivity and adsorptivity for cationic MB which depends on the presence of a basic functionalized pore surface. [ABSTRACT FROM AUTHOR]

A β-diketonate mononuclear dysprosium complex, with the formula [Dy(dpq)(BTFA)3] (1), has been prepared via self-assembly between 3-benzoyl-1,1,1-trifluoroacetone (BTFA) and dipyrido [3,2-d:2′,3′-f]quinoxaline (dpq) ligands. The crystallographic data reveal that the central Dy(III) ion is eight-coordinated by six oxygen atoms from three BTFA ligands and two N atoms from auxiliary dpq ligands, forming an approximately square-antiprismatic (SAP) coordination geometry with a D4d axial symmetry. Magnetic measurements point out that complex 1 exhibits single-molecule magnet (SMM) behaviours with an anisotropy barrier of 45.65 K under a zero direct-current (dc) field. With an applied dc field of 1200 Oe, the quantum tunnelling of the magnetization (QTM) is suppressed in 1 with an enhanced effective barrier of 178.42 K. A diamagnetic Y(III) analogue [Y(dpq)(BTFA)3] (2) and diluted species [Dy0.06Y0.94(BTFA)3(dpq)] (1@Y) were constructed to further perform the dilution experiment. The results unveil that the SMM behaviour observed in 1 is of molecular origin and is related to the single-ion magnetic behaviour of Dy(III) itself, even though the elimination of the dipolar and intermolecular interactions can modestly slow down the magnetic relaxation rate. The relaxation mechanisms and magneto-structure relationship are rationally discussed by ab initio calculations as well. [ABSTRACT FROM AUTHOR]

A series of five mononuclear β-diketonate-Dy(III) complexes, with formulas Dy(ntfa)3(Br-bpy) (1), Dy(ntfa)3(Br2-bpy) (2), Dy(ntfa)3(5,5-(CH3)2-bpy) (3), Dy(ntfa)3(4,4-((CH3)3)2-bpy) (4) and Dy(ntfa)3(4,4-(CH3)2-bpy) (5) (ntfa = 4,4,4-trifluoro-1-(2-naphthyl)-1,3-butanedione, Br-bpy = 5-bromo-2,2′-bipyridine, Br2-bpy = 4,4′-dibromo-2,2′-bipyridine, 5,5-(CH3)2-bpy = 5,5′-di-methyl-2,2′-bipyridine, 4,4-((CH3)3)2-bpy = 4,4′-di-tert-butyl-2,2′-bipyridine, and 4,4-(CH3)2-bpy = 4,4′-di-methyl-2,2′-bipyridine), have been prepared by altering the capping N-donor coligands. Dy(III) ions in all complexes possess N2O6 octa-coordinated environments, displaying a distorted square antiprismatic D4d symmetry in complexes 1–4, as well as a triangular dodecahedron D2d symmetry in 5. Magnetic investigations evidence the SIM behavior in the five complexes with the energy barriers (Ueff) of 104.19 K (1), 122.93 K (2), 84.20 K (3), 64.16 K (4) and 80.23 K (5) under zero applied dc field. The potential QTM effects in the title complexes are successfully suppressed in the presence of the extra applied fields. The crystal field parameters and orientations of the magnetic easy axes were obtained from the simulation of the magnetic data and the electrostatic model calculation. The distinct electronic effects originating from the subtle changes of the substituents on the capping N-donor coligands induce varying coordination microenvironments and geometries on the Dy(III) sites, further drastically impacting the overall magnetic properties of the title complexes. The disparities of the uniaxial anisotropy and the magnetic dynamics for 1–5 have been elucidated by ab initio calculations as well. [ABSTRACT FROM AUTHOR]

A β-diketonate mononuclear dysprosium compound, [Dy(DBM)2(bpy)(CH3OH)2]·Cl− (1) (DBM = dibenzoylmethane, bpy = 2,2′-bipyridine), has been prepared and structurally and magnetically characterized. The metal centers in 1 adopt an approximately square-antiprismatic (SAP) coordination environment with D4d axial symmetry. Magnetic investigations unveil that 1 displays slow magnetic relaxation of SMM behavior with an effective barrier (Ueff) of 25.13 K under a zero dc field as well as 68.30 K in the presence of a 1200 Oe dc field. The comparative studies of some known Dy(III)-based SIMs with DBM ligands show that the energy barriers can be significantly tuned by adjusting the distortion of the SAP configuration on DyIII ions. Ab initio calculations demonstrate that relaxation of the magnetization for 1 mainly takes place via the first excited-state Kramers doublet through Orbach, Raman, and thermally assisted quantum-tunnelling mechanisms. [ABSTRACT FROM AUTHOR]

The reactions of LnIII ions with a versatile pyridyl-decorated dicarboxylic acid ligand lead to the formation of a series of novel three-dimensional (3D) Ln-MOFs, [Ln3(pta)4(Hpta)(H2O)]·xH2O (Ln = Dy (1), Eu (2), Gd (3), Tb (4), H2pta = 2-(4-pyridyl)-terephthalic acid, x = 6 for 1, 2.5 for 2, 1.5 for 3 and 2 for 4). The Ln3+ ions act as nine-coordinated muffin spheres, linking to each other to generate trinuclear {Ln3(OOC)6N2} SBUs, which are further extended to be interesting 3D topological architectures. To the best of our knowledge, the Dy-MOF exhibits zero-field single-molecule magnet (SMM) behaviour with the largest effective energy barrier among the previously reported 3D MOF-based Dy-SMMs. The combined analyses of a diluted sample (1@Y) and ab initio calculations demonstrate that the thermally assisted slow relaxation is mainly attributed to the single-ion magnetism. Furthermore, fluorescence measurements reveal that H2pta can sensitize EuIII and TbIII characteristic luminescence. [ABSTRACT FROM AUTHOR]

A stable 3D In(III)-based metal–organic framework, [In(L)(μ2-OH)]·0.5H2O (1) (where H2L = 5-(1H-imidazol-1-yl)isophthalic acid), was successfully synthesized and fully characterized. As established by single-crystal X-ray diffraction, the compound 1 has a 4,6-connected 3D architecture crystalized in the monoclinic C2/c space group. On the basis of thermodiffractometry, 1 retains the crystallinity and the main framework below 450 °C. The structural integrity of 1 is sustainable in water, under harsh acidic and basic conditions (pH 2–13), and in common organic solvents, presenting excellent water stability and chemical stability. The photoluminescence properties of 1 are investigated as well. Remarkably, luminescence studies reveal that 1 can recognize Fe3+ ions with high selectivity from mixed metal ions in aqueous solution through a luminescence quenching phenomenon. The results suggest that the MOF may serve as a potentially useful sensory material for the detection of metal cations, and this work also demonstrates that highly hydrolytically stable In(III)-MOFs could be constructed and used for some meaningful applications in water. [ABSTRACT FROM AUTHOR]

Two mononuclear azido–cobalt(II) complexes, with the formulas [Co(3,3-Hbpt)2(N3)2(H2O)2] (1) and [Co(abpt)2(N3)2]·H2O (2) (3,3-Hbpt = 1H-3,5-bis(3-pyridyl)-1,2,4-triazole; abpt = 4-amino-3,5-bis(2-pyridyl)-1,2,4-triazole), have been prepared by altering the pyridyl-triazole coligands. In both complexes, the Co(II) centers feature hexa-coordinated environments with distorted octahedra in which the axial sites are identical, whereas the equatorial environments are finely modulated by the distinct chemical nature of the different coligands. It is worth noting that the distinct intermetallic distances in the two complexes (10.302 Å for 1 and 6.576 Å for 2) unambiguously cause a disparity in intermolecular interactions, implying their dissimilar magnetic behaviours. As a result, alternating current dynamic susceptibility measurements show that only 2 exhibits field-induced slow relaxation of magnetization with an effective energy barrier of 11.29 K, though large easy-axis magnetic anisotropies for both complexes are unveiled by combined analyses of the magnetic data and ab initio calculations. [ABSTRACT FROM AUTHOR]

We report that MoS2 nanosheets (MoS2 NSs) as a cocatalyst in situ coupled with MAPbI3 lead to a highly efficient composite photocatalyst for visible-light-driven photocatalytic H2 evolution. The most efficient MAPbI3/MoS2 NSs composite exhibits a high H2 evolution rate (206.1 μmol h−1) in MAPbI3-saturated HI solution, which is 121 times higher than that of pristine MAPbI3 (1.7 μmol h−1) and greatly superior to that of MAPbI3/Pt/C (68.5 μmol h−1), and the composite is very stable for H2 evolution in a 156 h reaction. [ABSTRACT FROM AUTHOR]

Two families of lanthanide(III) metal–organic frameworks (Ln-MOFs) constructed from a 2-(4-pyridyl)-terephthalic acid (H2pta) ligand, namely [Ln4(pta)5(Hpta)2(H2O)4]·xH2O (1-Eu, 2-Gd) and [Ln(Hpta)(C2O4)]·3H2O (3-Tb, 4-Dy, 5-Er and 6-Ho) (C2O4 = oxalic acid), have been discovered using the solvothermal method. On the basis of thermodiffractometry, all MOFs retain their crystallinity and main structure below 370 °C. Utilizing their excellent water stability and chemical stability, luminescence studies have been carried out. Notably, the Eu-metal organic framework (MOF) and Tb-MOF demonstrate pronounced luminescence, as well as high stability in water and other organic solvents. The luminescence explorations reveal that the Eu-MOF possesses good selectivity for testing Fe3+ in the aqueous phase via fluorescence quenching, while the Tb-MOF behaves as a multifunctional chemical sensor for the detection of Fe3+ cations and Cr2O72− anions in aqueous media and the recognition of nitrofuran (NIF) in DMF solvent. The recyclability and stability of Eu-MOF and Tb-MOF after the sensing experiments were observed to be adequate. By virtue of the superior stability, detection efficiency, applicability and reusability, Eu-MOF and Tb-MOF could be promising fluorescent materials for practical sensing applications. [ABSTRACT FROM AUTHOR]

In the presence of different nitrogen-rich ligands, two energetic MOFs with formulas [Ag(tza)]n (1) and [Ag(atza)]n (2) (Htza = tetrazole-1-acetic acid and Hatza = (5-amino-1H-tetrazole-1-yl) acetic acid) were successfully synthesized and characterized. X-ray single crystal structure analysis shows that both 1 and 2 have 2D layer-like topologies. The experimental and theoretical evaluations reveal the promising properties of both energetic compounds, such as prominent heats of detonation, high thermal stabilities, good sensitivities and excellent detonation performances. In contrast to 1, interestingly, the introduction of the amino group in 2 leads to various coordination modes of the ligands and different stacking patterns of the frameworks, resulting in the observation of the shorter Ag–O, Ag–Ag, C–N, N–N, and N＝N bond lengths in 2. Consequently, 2 features superior heats of detonation and thermostability compared to 1. The nonisothermal thermokinetic parameters are obtained by using the Kissinger and Ozawa methods, while the standard molar enthalpies of formation are calculated from the determination of constant volume combustion energies. In addition, both compounds were explored as practical additives to promote the thermal decomposition of ammonium perchlorate (AP). This work may provide an effective approach for manipulating the energetic properties and thermostability of high-energy compounds via the perturbation of energetic groups. [ABSTRACT FROM AUTHOR]

Complexation of dysprosium(III) ions with a multidentate hydrazone ligand, N-[(E)-pyridin-2-ylmethylideneamino]pyridine-2-carboxamide (L), in the presence of different β-diketonate coligands, leads to the formation of two novel DyIII dimers, with formulas Dy2(BTFA)4(L)2 (1) and Dy2(TTA)4(L)2 (2) (BTFA = 3-benzoyl-1,1,1-trifluoroacetone and TTA = 4,4,4-trifluoro-1-(2-thienyl)-1,3-butanedionate). They exhibit slightly different coordination geometries around DyIII centers and discrepant binuclear motifs – as a result of altering the β-diketonate coligands – which has an impact on the magnetic interactions between metal centers, the local tensor of anisotropy on each DyIII site and their relative orientations, therefore contributing to distinct magnetization dynamics. Compared to 2, complex 1 exhibits a more significant slow magnetic relaxation of SMM behavior in the absence of a dc field. The QTM effect is effectively repressed under a static field, resulting in the energy barriers of 57 K for 1 and 38 K for 2. Ab initio calculations clarify that, strong single-ion magnetic anisotropies exist in both complexes, whereas intermetallic ferromagnetic interaction and antiferromagnetic interaction are observed in 1 and 2, respectively, therefore resulting in dissimilar magnetization dynamics. [ABSTRACT FROM AUTHOR]

Transition metal layered double hydroxides (LDHs) have attracted wide public attention as highly promising non-precious metal electrocatalysts. Herein a ternary NiFeZr LDH was reported with excellent OER catalytic activity, benefiting from the rapid charge transfer caused by the synergistic effect of the doping of Zr and three-dimensional nanosheet structures. [ABSTRACT FROM AUTHOR]

High-throughput and large-scale patterning of enzymes with sub-10 nm resolution, the size range of individual protein molecules, is crucial for propelling advancement in a variety of areas, from the development of chip-based biomolecular nano-devices to molecular-level studies of cell biology. Despite recent developments in bio-nanofabrication technology, combining 10 nm resolution with high-throughput and large-scale patterning of enzymes is still an open challenge. Here, we demonstrate a high resolution and high-throughput patterning method to generate enzyme nanopatterns with sub-10 nm resolution by using thermochemical scanning probe lithography (tc-SPL). First, tc-SPL is used to generate amine patterns on a methacrylate copolymer film. Thermolysin enzymes functionalized with sulfonate-containing fluorescent labels (Alexa-488) are then directly immobilized onto the amine patterns through electrostatic interaction. Enzyme patterns with sub-10 nm line width are obtained as evidenced by atomic force microscopy (AFM) and fluorescence microscopy. Moreover, we demonstrate large-scale and high throughput (0.13 × 0.1 mm2 at a throughput of 5.2 × 104 μm2 h−1) patterning of enzymes incorporating 10 nm detailed pattern features. This straightforward and high-throughput method of fabricating enzyme nanopatterns will have a significant impact on future bio-nanotechnology applications and molecular-level biological studies. By scaling up using parallel probes, tc-SPL is promising for implementation to scale up the fabrication of nano-biodevices. [ABSTRACT FROM AUTHOR]

The utilization of two isomorphic ligands with different substituents leads to two centrosymmetric DyIII dimers, namely, [Dy2(bfbpen)2(H2O)2]·2I− (1) and [Dy2(bcbpen)2(H2O)2]·2I−·0.5H2O (2) (H2bfbpen = N,N′-bis-(2-hydroxy-5-fluoro-benzyl)-N,N′-bis-(pyridin-2-ylmethyl)ethylenediamine and H2bcbpen = N,N′-bis-(2-hydroxy-5-chloro-benzyl)-N,N′-bis-(pyridin-2-ylmethyl)ethylenediamine). Although Dy ions in both compounds uniformly exhibit a square-antiprism geometry, the critical difference found in the terminal substituents of the two ligands fine-tunes the local crystal field around Dy centers and the dinuclear molecular structures of 1 and 2. Magnetic investigations unveil that both 1 and 2 display dynamic magnetic relaxation of single-molecule magnet (SMM) behaviour with different energy barriers of 20.9 K for 1 and 72.7 K for 2 under a zero direct-current (dc) field, as well as 26.9 K for 1 under a 1200 Oe dc field. Compared to 1, the stronger uniaxial anisotropy and magnetic exchange in 2 render it a better SMM as evidenced by the higher energy barrier. Ab initio calculations are also performed on both Dy2 compounds to rationalize the observed discrepancy in their magnetic behaviours. The contribution illustrates that the SMM behaviour could be effectively enhanced by means of deliberate local structural manipulation. [ABSTRACT FROM AUTHOR]

By means of the solvent effect, three new azido-copper 1D coordination polymers, [Cu(4-aba)(N3)] (1), [Cu(4-aba)(N3)(CH3OH)] (2), and [Cu(4-aba)(N3)(C2H5OH)] (3) (4-aba = 4-azidobenzoic acid), were successfully prepared in the presence of Cu2+ ion, NaN3 and 4-azidobenzoic acid. Interestingly, 1 can be employed as a precursor and transformed to 2 and 3via the coordination of methanol or ethanol, respectively. Meanwhile, the identical products of 1, namely 1a and 1b, could be obtained from both 2 and 3 by a dealcoholized process. As a result, the geometric configurations of Cu(ii) ions vary from the tetracoordinated square-planar in 1 to the hexacoordinated octahedron in 2 or 3. Compound 1 displays a well-isolated 1D chain with dual-bridges of EO-azido and syn,syn-carboxylate, while isomorphic 2 and 3 are triple-bridged chain-like motifs containing EO-azido, syn,syn-carboxylate and μ2-alkanol. The structural transformations caused by the intervention of alkanol molecules modulate the intrachain Cu–Cu distances (3.570 for 1, 3.204 Å for 2 and 3.154 Å for 3) and Cu–N–Cu angles (127.3° for 1, 106.82° for 2 and 104.81° for 3). This modulation, however, further leads to different intrachain ferromagnetic interactions (J = 28.4 cm−1 for 1, 67.6 cm−1 for 2, 40.2 cm−1 for 3) that are qualitatively demonstrated by theoretical calculation. More importantly, the significant scenarios of magnetic ordering and slow magnetic relaxation, which are infrequent in most of the reported azido-copper cases, are only observed in 2 and 3, due to the distinct interchain networks among 1–3. In addition, heat-capacity measurements highlight the characteristics of long-range ferromagnetic ordering in 2 and 3. [ABSTRACT FROM AUTHOR]

Three metal–organic frameworks (MOFs), [Zn(pta)(H2O)]n (1) {[Zn(pta)]·H2O}n (2) and {[Cd(pta)]·H2O)}n (3) [H2pta = 2-(4-pyridyl)-terephthalic acid], were isolated by hydrothermal synthesis. Single-crystal X-ray analysis reveals that compound 1 shows a 2D layer-like network, while compounds 2 and 3 feature different 3D frameworks with Schläfli symbols of {4^2.6.8^3} and {4^6.6^4} respectively, in which the deprotonated pta2− ligands are indicative of diverse coordination modes. The thermostability, water stability and luminescent properties of 1–3 were investigated in the solid state at room temperature. It is noteworthy that 3 shows high selectivity for the detection of acetone in different solvents via a fluorescence quenching mechanism. By virtue of its excellent detection efficiency, applicability in water and reusability, compound 3 can be a promising fluorescent material for practical acetone sensing. [ABSTRACT FROM AUTHOR]

In situ grown amorphous molybdenum sulfide (MoSx) catalysts obtained by a photoreduction method have shown photocatalytic H2 evolution activity comparable to noble metals; however, the activity of the MoSx catalysts is still low due to the inevitable aggregation and the low intrinsic activity of active sites. Here, we report that in situ growth and activation of MoSx on ultrathin Co-containing metal–organic framework nanosheets (Co-BDC NSs, BDC: 1,4-benzenedicarboxylic acid) leads to the formation of a highly active H2 evolution catalyst (Co-BDC NSs/MoSx) in an erythrosin B-triethanolamine (ErB–TEOA) system under visible light irradiation (λ≥ 450 nm). During the photochemical synthesis of the Co-BDC NSs/MoSx catalyst, the ultrathin Co-BDC NSs can not only provide a large surface area to effectively anchor MoSx nanoparticles with a reduced size and a high dispersion, but also afford abundant coordinatively unsaturated and active Co sites to form highly active “CoMoS” sites; as a result, the Co-BDC NSs/MoSx catalyst exhibits a ∼20 times higher H2 evolution activity than free MoSx and an apparent quantum yield (AQY) of 15.0% at 500 nm. This work presents an efficient strategy to design highly efficient MoSx-based hybrid catalysts for solar photocatalytic H2 evolution reactions. [ABSTRACT FROM AUTHOR]

Based on different alkanol solvents, a family of azido–copper coordination polymers has been successfully synthesized. The as-synthesized compounds share the formula [Cu(4-tfmba)(N3)(solvent)]n, where 4-tfmba = 4-trifluoromethyl benzoic acid and solvent = CH3OH (1), C2H5OH (2) and C3H7OH (3). Single-crystal structure analysis indicates that the Cu(ii) centers in 1–3 are interconnected by an alternant triple-bridge of μ-1,1-azido, syn,syn-carboxy and μ2-alkanols, yielding homoplastically well-isolated 1D metal-chain patterns with tiny disparities in the geometric parameters. Noteworthily, the homologous alkanol solvents with growing carbon chain are not only the reaction solvents but are also employed to be the linkers to embed the structural frameworks of the resulting polymers, regulating in an orderly way the interchain structures and thus fine-tuning the magnetic behaviors of the resulting compounds. As a result, the predominant intrachain ferromagnetic exchanges caused by counter-complementarity of the threefold super-exchange channels are revealed in all three cases, finally giving rise to the ascending magnitudes of magnetic coupling effect (J = 56.21 cm−1 for 1, J = 68.94 cm−1 for 2 and J = 77.94 cm−1 for 3) and the well-organized scenarios of magnetic order and slow relaxation that are infrequent in known azido–Cu(ii) coordination networks. Among 1–3, the exchange of CH3OH for C2H5OH or C3H7OH, all of which coordinate through a single O atom, induces an interesting dynamic magnetic transition from a vitreous state to quasi-superparamagnet. Moreover, DFT calculations have been carried out to provide a qualitative and quantitative theoretic explanation of the magnetic behaviors of 1–3. [ABSTRACT FROM AUTHOR]

A novel one-dimensional azido-cobalt(ii) compound, [Co2(1-mbt)2(N3)4]n (1) (1-mbt = 1-((2-propyl-imidazol-1-yl)methyl)-benzo[1,2,3]triazole), was solvothermally synthesized. X-ray crystal structure analysis demonstrates that two crystallographically independent Co(ii) atoms in the asymmetrical unit of compound 1 exhibit a rectangular pyramid geometry. The 3D supermolecular network of 1 consists of well-isolated 1D metal chains in which the azido bridging ligands assume an unusual pattern of combination with the Co(ii) centre as the sign of [–EE–EO–EO–EO–]n. The various coordination modes of the azido anion are responsible for different magnetic exchanges between the adjacent Co(ii) ions. The end-to-end (EE) mode mediates the antiferromagnetic coupling, whereas the end-on (EO) manner contributes to the ferromagnetic interaction. Magneto-structural relationships are discussed with the aid of theoretical calculations which are employed to find the potential single-ion magnetic anisotropy and reproduce the observed magnetic coupling properly. Alternating current magnetic susceptibility measurements reveal that 1 features a typical behaviour of field-induced slow magnetic relaxation. Energetic characterization evidences that the resulting compound possesses satisfactory detonation properties, superior lack of sensitivity and thermostability owing to the high nitrogen content (N% = 40.10%) and a coherent intrachain configuration. The kinetic parameters of the exothermic processes for 1 are investigated by the Kissinger method and the Ozawa method. We note that 1 has potential application prospects as a new generation of environmentally friendly high-energy materials based on this nitrogen-rich and oxygen-free system. In addition, the compound is developed as a practical additive to promote the thermal decomposition of ammonium perchlorate (AP) and hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX). The finding in this work highlights an example of effective development of advanced magneto-energetic materials. [ABSTRACT FROM AUTHOR]

Herein, we report a highly active and durable single-atom Pt cocatalyst anchored onto g-C3N4 nanosheets (Pt–CN) for long-wavelength visible-light-driven photocatalytic H2 evolution. Upon spectral sensitization with Eosin Y (EY) dye, Pt–CN exhibits a ∼5-fold increase in specific activity over the Pt nanoparticles loaded g-C3N4 (Pt NPs–CN) under 520 nm irradiation and shows excellent recycling stability. [ABSTRACT FROM AUTHOR]

Multinary chalcogenide semiconductors (MCSs) recently emerged as a promising alternative to their binary counterparts for designing innovative solar energy conversion platforms due to a number of advantages including high absorption coefficient over a broad spectral range, conveniently tunable band structures through alloying, and nontoxicity for their use in real-world settings. The integration of MCSs with plasmonic metals into heteronanostructures is essential for promoting their light harvesting and conversion performance; however it is constrained by the large synthetic impediment arising from the incompatible activities of multiple precursors involved in growing the MCS domain via direct synthesis. Here using Au@Ag2ZnSnS4 core–shell nanocrystals (NCs) as a proof-of-concept demonstration, we report a new synthetic tactic based on cation exchange to access metal@MCS hybrid NCs with exceptional uniformity and precise control over the structural characteristics (both dimensions and morphology) in an aqueous environment. The prepared materials were explored as photoanodes for photoelectrochemical (PEC) hydrogen evolution, and the results suggested that our approach offers a good opportunity to unravel the delicate links between solar energy conversion efficiency and the structure of metal@MCS NCs. In view of the great versatility of cation exchange, we envision that this approach can be extended to fabricate a wide variety of metal@MCS NCs with unprecedented structures and functions. [ABSTRACT FROM AUTHOR]

Organizing magnetically discrete 3d transition metal ions, which behave as single-ion magnet (SIM) units, in a coordination network is a promising approach to design novel single-molecule magnets (SMMs). Herein a Co(ii)-based compound of formula [Co(3-Hppt)2(adip)(H2O)2]·2H2O (1), has been prepared and structurally analyzed by single-crystal X-ray crystallography. The structure of the title compound consists of well-isolated one-dimensional chains of Co(ii) ions where the octahedral metal atoms are spatially separated from each other by adipic acid bridges (Co…Co = 11.197 Å). The resulting compound presents a negative uniaxial anisotropy parameter (D = −33.9 cm−1) by the analysis of the direct current magnetic data, which is further probed by ab initio calculations. Alternating-current magnetic susceptibility experiments on 1 exhibit field-induced double magnetic relaxation processes with an anisotropic energy barrier of 38.8 K resulting from the single-ion anisotropy of the individual Co(ii) ions. [ABSTRACT FROM AUTHOR]

Two penta-coordinate Co2+ complexes, namely [Co(PDA)(H2O)2] (1) and [Co(PDA)(1,2-BIYB)0.5(H2O)]·(H2O) (2), (H2PDA = pyridine-3,5-dicarboxylate, 1,2-BIYB = 1,2-bis(imidazol-1-ylmethyl) benzene), which have similar ligand fields except for their local symmetries due to the different coordination atoms of Co2+, were synthesized, structurally analyzed, and magnetically investigated. Complexes 1 and 2 possess 3D supramolecular structures in which the 2D structures are further cross-linked by hydrogen bonds. Complex 1 can be observed to transform into 2 in the presence of 1,2-BIYB coligand, and 1 and 2 have distortion trigonal bipyramid geometries when the space group of Co2+ ion changes from C2/c in 1 to P2(1)/c in 2. Meanwhile, the average equatorial Co–O/N bond distances of CP 1 (2.1655 Å) are clearly larger than its axial Co–O bond distances (2.0704 Å); for CP 2, the average equatorial Co–O/N bond distances (2.0814 Å) are slightly shorter than the axial Co–O/N bond distances (2.0896 Å), which leads to different axial compression and distortion of the trigonal bipyramid metal environment. Fine-tuning of the structures arising from the auxiliary ligands has a definite impact on the magnetic properties of compounds 1 and 2. Both compounds share easy-plane magnetic anisotropies of their central Co2+ ions (D = 16 cm−1 for 1 and D = 59 cm−1 for 2) and different slow magnetic relaxations of magnetization with applied magnetic fields of 1500 Oe and 3000 Oe, respectively. [ABSTRACT FROM AUTHOR]

Highly compact ZIF-8 film coated stainless steel meshes (ZFCMs) are simply fabricated via the seeding method. The ZFCMs become more hydrophilic in air and close to superoleophobic under water. The prewetting induced underwater oleophobicity of the ZFCMs has been reported here for the first time. Water-prewetted ZFCMs possess excellent aqueous stability and can efficiently separate various oil/water mixtures. [ABSTRACT FROM AUTHOR]

Herein, we report a simple hydrothermal method for effectively grafting the Eosin Y (EY) dye onto TiO2 nanoparticles to afford a stable EY-sensitized TiO2 photocatalyst (EY-TiO2-HT), which shows an improved and stable H2 evolution activity under visible light (520 nm), achieving a 2.2 times higher turnover number for H2 evolution versus dye than the physical mixture of EY and TiO2 (EY-TiO2-mix). [ABSTRACT FROM AUTHOR]