CrystEngComm最新文献

Owing to their rich redox behavior and strong metal chelating ability, tetraoxolene ligands have been established as one of the foundational building blocks for multifunctional metal–organic materials. Here, we show how simple and often overlooked synthetic parameters can be used to control the structures of transition metal and lanthanide-based metal–tetraoxolene materials across multiple length scales. Through the synthesis of twelve new compounds, we provide a comprehensive survey detailing how the choice of solvent, initial ligand redox state, and in situ oxidant impact the local coordination geometry and chain architecture, as well as the crystal size and shape (e.g., rods vs. platelets). This work represents an important step towards the synthesis of new metal–tetraoxolene materials with predictable architectures and, therefore, targeted functionality.

In this work, we prepared lead-free Cs₃Bi₂I_9−xBr_x (x = 0, 1, 2, 3, 6, and 9) thin films using a green anti-solvent method under air conditions and used them to fabricate memristors with an Al/Cs₃Bi₂I_9−xBr_x/ITO structure. These memristors exhibited non-volatile and bipolar resistance switching behavior without electroforming. Notably, the bandgap of the Cs₃Bi₂I_9−xBr_x (x = 0, 1, 2, 3, 6, 9) series films was regulated by bromine doping. The switching ratio of devices changed with the films' band gap and increased from 10² to 10³. The resistance state of the Al/Cs₃Bi₂I_9−xBr_x/ITO devices was maintained even after 150 switching cycles and 10⁴ seconds of reading. Moreover, the Al/Cs₃Bi₂Br₉/ITO memristor showed excellent stability in the air after 100 days. This study offers beneficial insights into designing perovskite materials and regulating the performance of perovskite memristors.

Accurately designing and controlling the synthesis of circularly polarized luminescent (CPL) materials with both large asymmetry factor (g_lum) and high quantum yield (Φ_lum) values is a key scientific challenge. In this study, chiral ligands and luminescent π-conjugated systems are utilized as mixed ligands to form chiral helical polymers R/S-Ln-phen (Ln = Eu/Tb) by the regulation of intramolecular and intermolecular interactions. This approach aims to amplify the chirality and enhance luminescence efficiency. The compounds R/S-Eu-phen and R/S-Tb-phen demonstrated extremely high Φ_lum (86.88% for R/S-Eu-phen and 88.93% for R/S-Tb-phen) and relatively large g_lum (≈10⁻³) values.

A new salt-inclusion compound CsCl·(VOSe₂O₅)₄ was synthesized by the hydrothermal method, showing a linear spin-1/2 chain structure composed of corner-sharing VO₆ octahedra along the c-axis, where such spin-chains are stacked into a regular square lattice on the a–b plane. Magnetic measurements confirm that the title compound does not possess a long-range magnetic ordering down to 2 K, but shows a typical paramagnetic behavior.

This study presents the synthesis and characterization of a new zinc-based coordination polymer, {[Zn(BPMEDA)I]₂⁺·2I₃⁻}_n (zinc-CP), utilizing Zn(II) ions and the N,N′-bis(2-pyridylmethyl)-1,2-ethylenediamine tetrahydrochloride dihydrate (BPMEDA) ligand. Powder X-ray diffraction (PXRD), Fourier-transform infrared spectroscopy (FTIR), single-crystal X-ray diffraction (SCXRD), energy-dispersive X-ray spectroscopy (EDAX), scanning electron microscopy (SEM), and elemental mapping confirmed zinc-CP's structural integrity and composition. Furthermore, we assessed the stability of our crystal at different pH levels and evaluated its water stability by immersing the crystal in water over several days. The photoluminescence detection capability of zinc-CP was investigated with nine different antibiotics, revealing that the macrolide antibiotics, roxithromycin (RXM) and azithromycin (AZM), exhibited the highest limits of detection (LOD). Additionally, the photocatalytic degradation phenomenon of zinc-CP was assessed for the same antibiotics, demonstrating remarkable degradation rates of 97.59% for sulfadiazine (SDZ) and 94.52% for RXM. These findings demonstrate zinc-CP's potential as a sensitive sensor and photocatalyst for environmental pharmaceutical contaminants. Zinc-CP can identify and degrade pharmaceutical pollutants like antibiotics, indicating its potential for environmental cleanup. Zinc-CP's sensitive detection and catalytic breakdown make it a promising material for controlling pharmaceutical waste in water and other ecosystems in an environmentally responsible manner.

We have analyzed topological motifs of whole crystal structures and unconnected non-metal sublattices in 967 borides, 721 carbides, 899 nitrides and 927 silicides of metals within the periodic net model. In addition, we have classified the topological types of connected non-metal motifs in 333 carbides and 86 nitrides containing N–N or C–C bonds. The topology of the whole structure was found to be essentially predetermined by the sublattice motif; however, there were exceptions, which were caused by geometrical distortions of the structure. In contrast, sublattices of the same type can exist in different structural and topological types. We have proposed an integral criterion 〈G₃〉 of the sublattice distortion, which can also be considered as a measure of the sublattice uniformity. In most cases, the sublattices of non-metal atoms possess high uniformity, which reflects the tendency of the negatively charged atoms to be placed as distant as possible from each other. The sublattices, which have high symmetry, simple topology, and high uniformity in the most symmetrical embedding, were found to be the most suitable for the realization in different structures. The low uniformity of a sublattice indicates either strong interatomic interactions in the sublattice or its subordinate structural role.

In this study, we report on the synthesis and characterization of novel magnetic MoS₂/CoFe₂O₄/MIL101-(Fe) nanocomposite catalysts designed for the efficient reduction of toxic nitroaromatic compounds, such as nitrophenols and nitroanilines, to their corresponding amines at ambient temperature. The nanocomposites were engineered by integrating metal–organic frameworks (MIL101-(Fe)), flower-like MoS₂ microspheres, and CoFe₂O₄ nanocrystals using a hydrothermal method. The structural and physicochemical properties of the nanocomposites were thoroughly investigated using a suite of analytical techniques, including XRD, FT-IR, FE-SEM, EDX, VSM, BET surface area analysis, and zeta potential measurement. The results demonstrate that the MoS₂/CoFe₂O₄/MIL-101(Fe) nanocomposite exhibits high catalytic activity in the reduction of 4-nitrophenol (4-NP), 2-nitrophenol (2-NP), 2-nitroaniline (2-NA), and 4-nitroaniline (4-NA) to their respective amine derivatives. The conversion rates are notably high, with pseudo-first-order rate constants of 0.386, 0.086, 0.064, and 0.117 min⁻¹, respectively. Specifically, the complete conversion of these pollutants was achieved within 18–21 minutes, demonstrating the exceptional efficiency of the nanocomposite. Furthermore, the study explored the influence of catalyst dosage and reducing agent concentration on the reduction process's effectiveness. Notably, the magnetic nature of the nanocomposite facilitates its facile separation from the reaction mixture using an external magnet, significantly simplifying its recovery and reuse.

Coordination polymers (CPs) with high electrical conductivity have potential applications in electronic devices, sensors and energy storage systems. Herein, we present a Cd(II)-based two-dimensional (2D) CP [Cd₂(adp)₂(4-nvp)₄(H₂O)]·(H₂O)₇ [CP1; H₂adp = adipic acid and 4-nvp = 4-(1-naphthylvinyl)pyridine] and a Zn(II) based one-dimensional (1D) CP [Zn₂(adp)(4-nvp)₂(H₂O)(μ₃-OH)]·(H₂O)·(NO₃) (CP2) that exhibit electrical conductivity in the semiconducting regime and create a Schottky barrier diode (SBD) at the metal–semiconductor (MS) junction. However, CP1 shows higher conductivity as compared to CP2, which relates to the better orbital overlap of larger Cd(II) ions in CP1, providing a conjugation pathway for potent charge transport. These results are well-validated by theoretical prediction via density functional theory (DFT) computation based on band gap calculation. Such materials with semiconducting properties may pave the way for the fabrication of electronic and optoelectronic devices.

We report that the ligand-exchange reaction between [Ag(o-SPhCO₂H)]_n deposited on a solid substrate and the free p-HSPhCOOH ligand in solution results in crystal transformation from [Ag(o-SPhCO₂H)]_n to [Ag(p-SPhCO₂H)]_n on the substrate. Structural analysis revealed a structural transformation between CPs with different topologies via ligand exchange.

This study investigates the synthesis of zinc-based metal–organic frameworks (MOFs) using tetrahydrofuran (THF) as a solvent, focusing on forming distinct phases as models for potential battery applications. Contrary to expectations, the synthesis produced three unique phases: alpha, beta, and Zn-MOF-74a, instead of the anticipated Zn-MOF-74 structure. Comprehensive structural analysis using X-ray diffraction, infrared spectroscopy, and thermogravimetric analysis (TGA) revealed distinct crystallographic features for each phase, particularly the novel Zn-MOF-74a phase, which exhibits a heart-shaped pore structure and differs from the classic hexagonal MOF-74. The study also includes the first structural determination of the dry H₄DOBDC precursor, providing crucial insights for future research. The results demonstrate the significant impact of solvent choice, temperature, and pH on MOF phase formation and offer potential applications in energy storage and catalysis, especially for larger molecules. Further investigation is required to fully understand the electrochemical properties and phase stability of the newly identified Zn-MOF-74a and beta phases.