Crystallographic bibliography of Co-precipitate derived (311) Guite (Co3O4) crystalline materials

Upcycling recyclable waste materials into value-added products provides an opportunity to extend the life cycle of valuable resources. This act not only minimizes the exploitation of natural resource reserves but also reduces the volume of solid waste. In this study, waste polyethylene terephthalate (PET) was depolymerized via alkali hydrolysis to reclaim terephthalic acid (H 2 bdc). The reclaimed H 2 bdc was used as a linker to synthesize various iron terephthalate (Febdc) metal-organic frameworks (MOFs). For comparison, MOFs were also synthesized with commercially obtained linker under identical conditions. The effect of three different sources of iron, i.e., anhydrous FeCl 3 , FeCl 3 .6H 2 O and Fe(NO 3 ) 3 .9H 2 O were examined while keeping other synthesis parameters constant. The obtained MOFs were characterized to assess their crystallinity and phase, textural properties, morphology, functional groups, and thermal degradation behavior by powder X-ray diffraction (XRD), N 2 sorption isotherm measurements, scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR) and thermogravimetric analysis (TGA), respectively. The source of iron was found to influence the formation of a particular phase irrespective of the source of the linker. Specifically, the use of anhydrous FeCl 3 resulted in the formation of MOF-235(Fe) phase while FeCl 3 .6H 2 O yielded MIL-101(Fe) phase and Fe(NO 3 ) 3 .9H 2 O produced nanocrystalline material. However, using HCl as a reaction modulator along with Fe(NO 3 ) 3 .9H 2 O resulted in the formation of crystalline material belonging to MIL-68(Fe) phase. Finally, the synthesized MOFs were examined for CO 2 capture application via gravimetric method. The MOFs obtained from reclaimed linkers showed similarity in their material properties or CO 2 uptake performance compared to their commercial counterpart.

High volumes of untreated wastewater are discharged into various water bodies worldwide, leading to the distortion and deterioration of the aquatic environment. The use of untreated wastewater to irrigate food crops often results in food poisoning-related deaths due to high levels of pollutants, including heavy metals. Herein, bimetallic oxides (Ag 2 O/ZnO) were incorporated on the surface of multiwall carbon nanotubes (MWCNTs) by wet impregnation at different mixing ratios to design Ag 2 O/ZnO/MWCNTs nanocomposites (AZM X ), which were used for the removal of Cr, Pb and Zn ions from irrigation water. The synthesized nanocomposites were characterized by BET, XRD, TEM, and SEM/EDS to confirm the successful incorporation of Ag 2 O/ZnO on the surface of MWCNTs. The characterization results confirmed the formation of highly crystalline materials with enhanced surface area, which can be attributed to the improved dispersion and interfacial interaction between Ag₂O/ZnO and MWCNTs. This synergistic effect increases the effective surface area regardless of the mixing ratios relative to individual nanoparticles. Among the tested heavy metals, Pb showed the highest removal efficiency (98.62%) using the AZM 2:1:1 nanocomposite under optimum conditions of dosage (0.8 g) and contact time (25 min). The adsorption data fitted well with the Langmuir isotherm model, suggesting that the heavy metals adsorbed to the surface of AZM X in a monolayer fashion. The adsorption kinetics revealed that the adsorption process was better explained by pseudo-second-order kinetics. Thermodynamic studies demonstrated that the metal ion adsorption by AZM X was spontaneous, feasible, and endothermic. The desorption study revealed that hydrochloric acid was the most effective desorbing agent. The AZM 2:1:1 nanocomposite maintains more than 90% removal rate of Pb after five regeneration cycles. This study suggested that the developed novel bimetallic oxides–MWCNTs nanocomposites are capable of efficiently removing metal ions from aqueous environments. • A novel AZMx composites was designed for effective metal ions removal. • Characterization confirmed successful incorporation of Ag 2 O/ZnO on MWCNTs surface. • Adsorption followed pseudo-second-order kinetics and Langmuir isotherm. • Thermodynamic analysis showed the process is endothermic and spontaneous. • AZM2:1:1 showed better adsorption performance toward Cr(VI), Pb(II), and Zn(II). • The AZM2:1:1 retained 90% of Pb removal even after 5 reuse cycles.

Amorphous systems lack long-range order, making their properties strongly dependent on short-range order (SRO) and medium-range order (MRO) structural motifs and their network connectivity. While graph neural networks (GNNs) excel for crystalline materials, their performance on amorphous systems is limited by graph construction ambiguities, message-passing bottlenecks, data scarcity, and transferability issues. This review surveys traditional descriptors and then focuses on topological approaches: complex network descriptors, persistent homology, rigidity theory (also known as topological constraint theory), and graph limit metrics. We summarize how rings, voids, and percolating backbones correlate with mechanics, transport, and thermodynamics across metallic glasses, oxide glasses, polymers, and organic semiconductors, among others, highlighting their potential to inform the exploration and design of amorphous energy materials. Finally, we provide a shortlist of topological variables with potential for property modeling and set out three directions in datasets, unified topology modeling and topology aware GNN architectures.

Covalent organic frameworks (COFs) are crystalline porous materials featuring ordered π arrays and well-defined channels, whose structures can be rationally designed through topology-guided polymerization. Over the last two decades, the development of diverse π-building units bearing various reactive groups has enabled a wide range of COF architectures. Particularly, aldehydes are the most extensively employed monomers for constructing COFs ranging from azine to imine, squaraine, hydrazone, and olefinic linkages. However, ketones, a handy analogue to aldehydes with even richer diversity, remain to be well explored as monomers for the design and synthesis of COFs. Here we report acylhydrazone-linked COFs by exploring ketones as building units to condense with hydrazides under solvothermal conditions. We observed that a careful screening of reaction conditions including solvent, catalyst, temperature, and time enables the finding of optimal systems to produce highly crystalline and porous acylhydrazone-linked COFs with designable micro- and mesoporosity. Surprisingly, the acylhydrazone linkage plays a decisive role in both structural formation and functional evolution. For the pores, the acylhydrazone linkage strengthens pore confinement, enhances water adsorption, and increases adsorption heat. Concurrently, for the skeletons, it enhances thermal and chemical stabilities, promotes π-delocalization, enables tunable light emission, decreases bandgaps, and improves photoconductivity. These findings introduce a new paradigm for designing COFs with acylhydrazone linkages to create unparalleled structures, properties, and applications.

The fabrication of crystalline stimuli-responsive materials with high-contrast and rapid-response behavior and establishing an efficient strategy system for performance regulation are highly appealing for the development of intelligent materials. In this context, four novel multistimuli-responsive functional coordination polymers (CPs), {[Ln(m-bcbp) (NDC)0.5(H2O)1.5(NO3)0.5]·Cl·(NO3)}n (Ln = Eu, CP 1-Eu; Ln = Dy, CP 1-Dy) and {[Ln(m-bcbp) 0.5(NDC) (H2O)2]·Cl}n (Ln = Eu, CP 2-Eu; Ln = Dy, CP 2-Dy), based on viologen ligand and lanthanide ions were successfully prepared and systematically characterized. All CPs exhibit fast and reversible chromic responses under UV irradiation and applied voltage, enabled by the strong electron-donating ability of the electron-rich ancillary ligands, excellent redox activity of viologen, and distinct π-π stacking between them. Moreover, the formation of viologen radicals via photoinduced electron transfer (PIET) confers upon these compounds highly contrasted photomagnetic (30.8% reduction for CPs 1-Dy) and photoluminescent (95.4% quenching for CPs 1-Eu) responses. Furthermore, based on the well-defined crystal structure, the intrinsic coordination flexibility, and the diverse photoresponsive behavior, the performance regulation mechanism was comprehensively elucidated.

The chirality-induced spin selectivity (CISS) effect provides a nonmagnetic route to generate spin-polarized charge transport, yet converting spin selectivity into intrinsic chemical asymmetry within crystalline materials remains a fundamental challenge. Here, we report an enantiomeric pair of chiral helical Fe- and Cr-based metal-organic frameworks (MOFs) assembled from homochiral bipyridine ligands and trinuclear metal clusters, which function as intrinsically spin-polarizing platforms for enantioselective electropolymerization. Single-crystal X-ray diffraction (SC-XRD) reveals long-range helical architectures featuring continuous one-dimensional transport channels. Magnetic conductive atomic force microscopy (mc-AFM) demonstrates pronounced CISS behavior, with spin polarization ratios reaching up to 90% for the Fe-MOFs and ∼74% for their Cr analogues, reflecting metal-dependent spin-orbit coupling (SOC) effects. When processed as thin films on nonmagnetic electrodes, the Fe-MOFs intrinsically generate spin-polarized currents without external magnetic fields and govern the stereochemical outcome of electropolymerization, enabling the enantioselective growth of polythiophene derivatives from achiral monomers. In contrast, the isostructural Cr-MOFs exhibit weaker spin polarization and induce reduced chiral responses during polymerization. Notably, this work represents the first demonstration of CISS-driven asymmetric electropolymerization originating from chiral materials and identifies chiral MOFs as a versatile platform for translating CISS into enantioselective chemical synthesis.

Dynamic covalent chemistry has enabled adaptive behavior in organic polymer networks and molecular crystals, yet analogous control in inorganic crystalline solids remains largely unexplored. Here we show that elemental selenium can operate as a dynamic covalent inorganic crystal, whose architectural and functional adaptability arises from dynamic covalent Se─Se bonds within the trigonal selenium backbone. External mechanical (or optical) stimuli drive Se─Se bond cleavage and reformation, mediating structural reconfiguration of the crystalline framework. Embedding selenium in a crosslinked polymer matrix creates a mechanically programmable environment that exerts real-time and persistent mechanical signals in situ. Under this chemo‑mechanical coupling, crystal branching frequency and three-dimensional architecture respond to matrix stiffness and external light, and these translate directly into tunable dielectric behavior in polymer-selenium composites. This work expands dynamic covalent chemistry from organic to inorganic crystalline materials, and reveals dynamic covalent inorganic crystals as a new class of adaptive materials.

Crystalline materials that exhibit attractive mechanical responses under external stresses have attracted considerable interest due to their potential applications across multiple fields. Here, we present a crystalline form of 9-fluorenone hydrazone (9-FH) that exhibits dual mechanical stress response, that is, plasticity and elastoplastic behavior, on different crystallographic faces. This dual mechanical response arises from specific molecular packing features, wherein intermolecular interactions play a key role in modulating the crystal's mechanical properties from the different faces. Here, large 9-FH single crystals demonstrate excellent plastic behavior under applied forces, attributed to the reorganization of weak interactions across the slip planes. Moreover, this comprehensive analysis offers detailed insights into the distinct mechanical responses of 9-FH and the underlying mechanism.

Porous crystalline materials traditionally rely on robust coordination or covalent bonds. Herein, we report a new C3-symmetric molecular nanographene 1 containing three hexabenzocoronene (HBC) units that self-organizes into a permanently porous framework exclusively using weak van der Waals interactions. Single-crystal x-ray diffraction results reveal a propeller geometry with C3 symmetry, forming two-dimensional honeycomb sheets parallel to the ab plane stabilized by π···π and C-H···π interactions. Nitrogen adsorption measurements at 77K confirm a Type I(b) isotherm with a record-breaking Brunauer-Emmett-Teller (BET) surface area of 1108m2 g-1, the highest reported to date for purely organic van der Waals frameworks. Furthermore, compound 1 exhibits aggregation-induced emission (AIE) and remarkable thermal stability up to 290°C. These results demonstrate that carefully designed nanographenes can achieve high structural predictability and robust porosity without the need for metal nodes or covalent linkages, opening new avenues for gas storage applications.

ABSTRACT Porous crystalline materials traditionally rely on robust coordination or covalent bonds. Herein, we report a new C 3 ‐symmetric molecular nanographene 1 containing three hexabenzocoronene (HBC) units that self‐organizes into a permanently porous framework exclusively using weak van der Waals interactions. Single‐crystal x‐ray diffraction results reveal a propeller geometry with C 3 symmetry, forming two‐dimensional honeycomb sheets parallel to the ab plane stabilized by π···π and C–H···π interactions. Nitrogen adsorption measurements at 77 K confirm a Type I(b) isotherm with a record‐breaking Brunauer–Emmett–Teller (BET) surface area of 1108 m 2 g −1 , the highest reported to date for purely organic van der Waals frameworks. Furthermore, compound 1 exhibits aggregation‐induced emission (AIE) and remarkable thermal stability up to 290° C. These results demonstrate that carefully designed nanographenes can achieve high structural predictability and robust porosity without the need for metal nodes or covalent linkages, opening new avenues for gas storage applications.

The theoretical identification of crystalline topological materials has enjoyed sustained success in simplified materials models, often by singling out discrete symmetry operations protecting the topological phase. When band structure calculations of realistic materials are considered, complications often arise owing to the requirement of a consistent gauge in the Brillouin zone, or down to the fineness of its sampling. Yet, the Berry phase, acting as topological label, encodes geometrical properties of the system, and it should be easily accessible. Here, an expression for the Berry phase is obtained, thanks to analytical Bloch states constructed from an infinite series of s-type Gaussian orbitals.Two contributions in the Berry phase are identified, with one having an immediate geometric interpretation, being equal to the Zak phase. Eigenvalues of a modular symmetry, considered here for the first time in the context of crystalline solid state systems, are put in correspondence with the Zak phase: modular symmetries allow to define a non-trivial action for the spatial inversion also when the system does not have an inversion centre, as for the considered case of space group no. 22 (F222), which is known to host symmetry equivalent Bloch states distinguishable by their Berry phase.

Chiral hybrid metal halides (CHMHs) have emerged as a promising class of ionic crystalline materials for circularly polarized luminescence (CPL). In these materials, organic cations primarily act as chirality sources, whereas the inorganic frameworks serve as the luminescent centers. The interactions between chiral organic cations and inorganic frameworks enable intrinsic CPL emission. The soft and ionic nature of CHMHs further distinguishes them from conventional covalent luminophores, offering exceptional structural and chiroptical tunability. This tutorial review summarizes recent progress in CPL-active CHMHs, focusing on the fundamental routes for CPL generation, amplification and application. Representative synthetic strategies for CHMHs are introduced, followed by an analysis of luminescence mechanisms and their relevance to CPL generation. Key strategies to enhance CPL performance, including composition engineering and external-field regulation, are also reviewed. Beyond fundamental understanding, emerging applications enabled by the unique properties of CHMHs, including circularly polarized light-emitting diodes, CPL-resolved scintillators, and anti-counterfeiting technologies, are summarized. Finally, key challenges and future perspectives are outlined to guide the development of high-performance CHMH-based chiroptical materials and devices.

The development of self-powered micro-energy sources is critical for internet of things, wearable electronics and implantable medical devices.γ-Glycine, a biocompatible piezoelectric material, shows great application potential in this field. However, its practical use is limited by the difficulty in achieving macroscopic dipole alignment ofγ-glycine crystals. Herein, an electric field-assisted physical vapor deposition (PVD) strategy is proposed to address this challenge. By applying a continuous DC bias field during PVD crystallization, macroscopically polarizedγ-glycine arrays with uniform molecular orientation have been successfully fabricated. Systematic characterizations using XRD, SEM, and PFM confirm enhanced crystallinity,γ-phase purity, and uniform polarization orientation. Piezoelectric energy harvesters based on these arrays exhibit a maximum open-circuit voltage of 0.25 V under 40 N periodic compression-over 400% higher than devices prepared without the electric field. Density functional theory calculations further reveal that directional hydrogen bonding in the non-centrosymmetric P31crystal structure enhances dielectric polarization and piezoelectric response. This work is devoted to providing a scalable route to high-performance biocompatible energy harvesters and offering new insights into controlling polar orientation in molecular crystalline materials.

Liquid crystal elastomers are unique choices for designing the next generation soft robots. Their synthesis relies exclusively on the polymerization/crosslinking of reactive mesogens with high molecular rigidity, necessitating high energy input to disrupt the molecular order for their actuation function. We report a non-mesogenic route towards designing liquid crystal elastomers. The monomeric precursors are non-mesogenic, but the supramolecular interactions are amplified in the polymerized network due to their cooperative nature, leading to liquid crystallinity. This allows resolving the common conflict between high actuation strain and low energy input, making it possible to design soft robots that can operate autonomously by harnessing the serendipitous energy from natural environments. Our molecular design broadens the scope of liquid crystalline materials, with potential implications beyond elastomeric actuators.

The characterization of ultrathin crystalline materials remains challenging because of their unique structural features, which limit the application of conventional X-ray powder diffraction (PXRD). Here, we present a general quasi-periodic sampling (QPS) method for accurately simulating and interpreting the PXRD patterns of such materials. The approach reconstructs diffraction signals by transforming low-dimensional crystals into three-dimensional periodic systems through the introduction of a pseudo-superlattice and a sufficiently thick vacuum layer. This modeling approach is compatible with most standard PXRD simulation software. Using this method, we systematically investigated close-packed metals, two-dimensional metal-organic frameworks (2D MOFs), and diverse inorganic layered materials to establish relationships between atomic structures and PXRD patterns. This work provides a cost-effective and reliable computational tool for structural analysis of ultrathin crystalline materials, with broad applicability in the rational design of such systems.

Coordination materials are pivotal for advancing multidisciplinary science. Conventional synthetic methods, solid-, liquid-, and gas-phase, suffer from limited reactant scope and poor control over product formation, hindering fundamental research and applications. Here, we introduce a heterogeneous in situ approach using zero-valent metals as cation sources in water, combined with linker supersaturation. This enables universal, eco-friendly, and scalable synthesis of crystalline coordination materials. We demonstrate its power by solving the challenge of synthesizing titanium coordination compounds, previously inaccessible via conventional routes. The resulting titanium materials display diverse dimensionalities, structural variety, and broad functional-group tolerance, highlighting their promise for adsorptive separation. Notably, the method extends broadly across metals, including rare earths, transition and main-group metals. Thus, it establishes a general paradigm for heterogeneous in situ synthesis in coordination chemistry and enables energy-efficient production of advanced separation materials. Our work redefines coordination material synthesis and accelerates the development of inorganic-organic hybrid solids.

A nonporous metal-organic material (MOM) captures water from the atmosphere under ambient conditions upon exposure to light. The water capture is achieved via a single-crystal-to-single-crystal [2 + 2] photocycloaddition. The MOM adopts an unusual condensed version of the primitive cubic (pcu) topology. The light generates isolated cavities within the crystal lattice that capture the water with overall retention of the pcu topology. The work underscores how MOMs can be advanced for controlled water capture with implications for sustainable water resource development, exemplifying how nonporous crystalline materials can be developed to capture small molecules from the atmosphere in the presence of light.

Abstract Molecular dynamics simulations play a crucial role in scientific research. Yet their computational cost often limits the timescales and system sizes that can be explored. Most data-driven efforts have focused on reducing the computational cost of the accurate interatomic forces required to solve the equations of motion. However, despite their success, these machine-learning interatomic potentials are still bound to small time steps. In this work, we introduce TrajCast, a transferable and data-efficient framework based on autoregressive equivariant message-passing networks, that directly updates the atomic positions and velocities, lifting the constraints imposed by traditional numerical integration. We benchmark our framework across various systems, including a small molecule, crystalline material and bulk liquid, demonstrating excellent agreement with reference molecular dynamics simulations for structural, dynamical and energetic properties. Moreover, we show that TrajCast can generalize in a zero-shot manner to unseen regions of phase space, producing physically meaningful ensembles in metastable equilibrium and out-of-equilibrium regimes beyond the training data, without compromising accuracy. Depending on the system, TrajCast allows for forecast intervals up to 30× larger than traditional MD time steps, generating over 15 ns of trajectory data per day for a solid with more than 4,000 atoms. By enabling efficient, large-scale simulations over extended timescales, TrajCast can accelerate materials discovery and explore physical phenomena beyond the reach of traditional simulations and experiments.

Piezoelectricβ-glycine is a promising molecular crystal, yet its controlled preparation remains challenging. Current nanoconfinement strategies, which rely primarily on rigid templates or simulations, cannot reliably capture the intrinsic confinement regime that leads toβ-phase formation. Here, we propose electric-field-driven nanoconfinement as a one-step, continuous, and interface-free approach to investigate glycine crystallization and to define the confinement regime that yields theβ-phase. We produced glycine nanoparticles via electrohydrodynamic spraying under a direct current field, automatically varying the spraying height to modulate nanoconfinement during nucleation and growth. Structural, morphological, and piezoelectric characterizations reveal that pureβ-glycine forms within a crystal radius range of 5-120 nm. By integrating these findings with thermodynamic and kinetic analysis, we elucidate the mechanism ofβ-phase formation and construct a crystallization phase map that delineates the confinement conditions necessary for its stabilization. This work identifies the critical nanoconfinement parameters for accessing piezoelectricβ-glycine and provides fundamental insights into polymorph control in molecular crystalline materials.