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Regulation of the complex structure is greatly significant for the preparation of single-molecule magnets (SMMs). In this work, a multidentate ligand of N,N′-bis(3-carboxy-4-hydroxyphenyl)-1,4,5,8-naphthalenetetradicarboximide (H4NDISA) has been synthesized and reacted with dysprosium(III) salt. By controlling the ratio of metal ions to the ligand and reaction temperature, three new dysprosium(III) complexes are obtained, namely, [Dy2(H2NDISA)3(DMF)3(H2O)10]·1.4DMF·2.6H2O (1), {[Dy(H2NDISA)1.5(DMF)(H2O)4]·3DMF·4H2O}n (2), and {[Dy(HNDISA)(H2O)2]·4H2O}n (3). Their structures are determined by single crystal X-ray diffraction. Crystallographic data demonstrate that complex 1 is a dinuclear dysprosium(III) complex linked by the bidentate ligand of H4NDISA. The intramolecular Dy(III)⋯Dy(III) distance is 23.0861(7) Å. In complex 2, the carboxyl group in one of the ligands adopts a μ-η2:η1 bridging mode to connect two Dy(III) ions, resulting in a Dy(III)⋯Dy(III) distance of 5.2611(5) Å. The other ligand adopts a tetradentate coordination mode to bridge two Dy(III) ions, forming an infinite one-dimensional chain structure along the c axis. Complex 3 displays a two-dimensional network structure. One carboxyl group in the ligand adopts a μ-η1:η1 bridging mode growing along the c axis. Another carboxyl group in the ligand adopts a μ-η2:η1 bridging mode. The shortest distance of Dy(III)⋯Dy(III) is 4.6138(5) Å. DC and alternating current (AC) magnetic susceptibilities of complexes 1–3 were measured. AC magnetic susceptibility measurements show that complexes 1–3 exhibit frequency-dependent ac susceptibilities. [ABSTRACT FROM AUTHOR]

An asymmetric strategy is a constructive means to regulate the energy and properties of energetic materials. In this work, a series of asymmetric energetic compounds based on bi(1,2,4-triazole) were designed and synthesized, and the related structural features and performances were systematically investigated by NMR spectroscopy, FT-IR spectroscopy, MS, EA, and DSC for their impact on asymmetric functional groups. Among them, a single trinitromethyl group-modified energetic compound termed "TNBN" was confirmed by X-ray single-crystal diffraction analysis. Benefiting from the asymmetric trinitromethyl groups, the structure of TNBN showed a unique stacking pattern, and exhibited good detonation performance (8787 m s−1 and 31.1 GPa) and acceptable insensitivity to mechanical stimuli (IS = 30 J and FS = 288 N) compared with its similar symmetric counterparts. This work aids understanding of the structure–performance relationship of asymmetric energetic compounds and demonstrates that appropriate modulation of the asymmetric trinitromethyl group is an effective approach to achieve high-energy insensitive energetic materials. [ABSTRACT FROM AUTHOR]

The design of novel energetic compounds constitutes a pivotal research direction within the field of energetic materials. However, exploring the intricate relationship between their molecular structure and properties, in order to uncover their potential applications, remains a challenging endeavor. Therefore, employing multi-molecule assembly techniques to modulate the structure and performance of energetic materials holds immense significance. This approach enables the creation of a new generation of energetic materials, fueling research and development efforts in this field. In this study, a series of coordination compounds are synthesized by utilizing tetranitroethide (TNE) as an anion, which possesses a high nitrogen and oxygen content. The synthesis involves the synergistic modification between metal ions and small molecule ligands. Characterization of the obtained compounds is carried out using various techniques, including single crystal X-ray diffraction, IR spectroscopy, elemental analysis, and simultaneous TG–DSC analysis. Additionally, the energy of formation for these compounds is calculated using bomb calorimetry, based on the heat of combustion. The detonation performances of the compounds are determined through calculations using the EXPLO 5 software, and their sensitivities to external stimuli are evaluated. [ABSTRACT FROM AUTHOR]

Exosomes have attracted increasing attention in the early diagnosis of tumors due to their participation in physiological and pathological processes. Herein, a novel label-free aptasensor based on the CuNi bimetallic metal–organic frameworks (MOFs) that was decorated with MXene quantum dots (MQDs) was fabricated for exosome sensing. The CuNi-MOFs functionalized with dual specific aptamers, CD63 and MUC1, served as an ideal nanocarrier and catalyst for efficient recognition and capture of target exosomes. Meanwhile, the MQDs with excellent electron transfer can promote the electrochemical catalytic performance of this designed aptasensor. It is noteworthy that the large specific surface area of 2D bimetallic CuNi-MOF nanosheets can offer plenty of exposed active sites and facilitate the connection of aptamers, thereby achieving the goal of specific capture and detection of exosomes. The as-prepared electrochemical aptasensor possesses a wide linear range of 1 × 101 to 1 × 106 particles μL−1 for exosome detection and a low detection limit of 5 particles μL−1 (S/N = 3). Besides, the as-prepared aptasensor exhibited satisfactory electrochemical stability for the detection of exosomes, which can provide new ideas for clinical detection and tumor diagnosis. [ABSTRACT FROM AUTHOR]

The discovery of unconventional scale-free ferroelectricity in HfO 2 -based fluorite thin films has attracted great attention in recent years for their promising applications in low-power logic and nonvolatile memories. The ferroelectricity of HfO 2 is intrinsically originated from the widely accepted ferroelectric metastable orthorhombic Pca 2 1 phase. In the last decade, defect-doping/solid solution has shown excellent prospects in enhancing and stabilizing the ferroelectricity via isovalent or aliovalent defect-engineering. Here, the recent advances in defect-engineered HfO 2 -based ferroelectrics are first reviewed, including progress in mono-ionic doping and mixed ion-doping. Then, the defect-lattice correlation, the point-defect promoted phase transition kinetics, and the interface-engineered dynamic behaviour of oxygen vacancy are summarized. In addition, thin film preparation and ion bombardment doping are summarized. Finally, the outlook and challenges are discussed. A multiscale structural optimization approach is suggested for further property optimization. This article not only covers an overview of the state-of-art advances of defects in fluorite ferroelectrics, but also future prospects that may inspire their further property-optimization via defect-engineering.