CrystEngComm最新文献

Mechanochemical preparation of multi-component systems, such as cocrystals and salts, is at the forefront of crystal engineering, driven by its dual benefits of environmental friendliness and efficient material exploration. The intrinsic relationship between mechanochemical milling and supramolecular chemistry arises from the solvent-free nature of the milling process. This study reports the new salts of antifibrinolytic agents, aminocaproic acid (ACA) and aminomethylbenzoic acid (AMA), with various coformers, namely oxalic acid (OXA), tartaric acid (TAT), caffeic acid (CAF), 2-chloro-4-nitrobenzoic acid (CNB), saccharin (SAC), and orotic acid (ORA). Additionally, the crystal structure of the anhydrous AMA compound was determined and reported in this work. The crystal structures of the developed salts were elucidated using single-crystal X-ray diffraction analysis and further analysed by spectroscopic (FT-IR) and thermal methods (DSC and TGA). The salts of ACA with OXA resulted in two solid forms with varying stoichiometry of water molecules (ACA–OXA–H₂O (1 : 1 : 2); ACA–OXA–H₂O (1 : 1 : 1.5)), while ACA–CAF–H₂O was obtained in a 3 : 2 : 2.6 stoichiometric ratio of ACA, CAF, and H₂O in the asymmetric unit. AMA–TAT and AMA–CNB were obtained as hydrates, while AMA–OXA, AMA–SAC, and AMA–ORA were obtained as anhydrous salts. Bulk quantities of ACA and AMA salts were synthesised using both solution-based and mechanochemical ball milling techniques. Unlike conventional solution-based approaches, which typically consume significant amounts of solvents and energy, this study highlights the influence of various ball milling parameters, such as milling media, ball size, frequency, and duration, under both solvent-assisted and neat grinding conditions for the preparation of multicomponent solids of ACA and AMA. A linear correlation was observed between the percentage completion and milling frequency of the ball mill, as well as the time required for completion of the salification process. Interestingly, the different hydrate forms of ACA–OXA (ACA–OXA–H₂O (1 : 1 : 2) and ACA–OXA–H₂O (1 : 1 : 1.5)) were prepared in bulk quantities by ball milling, by fine-tuning the milling parameters, whereas the solvent-based slurry method resulted in only the ACA–OXA–H₂O (1 : 1 : 2) form.

Previous studies have shown that particle size and core–shell structure have a great impact on the electromagnetic parameters and microwave absorbing performance of materials. Here, ZnFe₂O₄ nanoparticles with a particle size of approximately 4 nm were successfully synthesized using a magnetic field-assisted steam–thermal method at 120 °C. The synthesized ZnFe₂O₄ nanoparticles were coated with silica (SiO₂) and carbon (C). The ZnFe₂O₄@C composite exhibited significantly superior microwave absorption performance, attaining a strong absorption peak of −46.2 dB at 8.80 GHz. We conducted a systematic investigation on their microstructures, electromagnetic parameters and microwave absorption performance. These results not only shed light on the understanding of interfacial effects induced by high-density interfaces formed by ultra-fine particles within the coating but also provide an appealing mode for the implementation of heterogeneous interfacial engineering using coatings.

This study successfully achieved the growth of heavily nitrogen-doped polycrystalline silicon carbide (poly-SiC) crystals via the physical vapor transport (PVT) method. Notably, poly-SiC crystals with a low resistivity of 12 mΩ cm were obtained through process optimization, demonstrating significant advancement in electrical performance. The systematic investigation focused on three critical aspects – growth temperature, chamber pressure, and post-growth wafer processing – with their synergistic effects on crystal quality comprehensively demonstrated through resistivity mapping, polytype characterization and growth rate analysis. Experimental results revealed that temperature predominantly governs the resistivity of nitrogen-doped poly-SiC through doping efficiency. By implementing a specially designed parameter decoupling strategy involving orthogonal experimental arrays and furnace structural modifications, we effectively resolved the complex inter-dependencies among temperature and pressure. By developing an advanced PVT method with low cost and easily controlled growth conditions, low-resistivity poly-SiC wafers can be produced and processed as a material for wafer bonding application.

Controlling the material properties of crystalline pharmaceutical materials is essential for developing materials with robust performance and manufacturability. Identification of the crystal facets present in a material opens up the opportunity for developing strategies to control and engineer material to meet manufacturing needs. This proof of concept study presents a workflow for using powder X-ray diffraction (PXRD) and angle resolved polarised Raman spectroscopy (ARPRS), in combination with density functional theory (DFT) calculations, to identify facets in samples unsuitable for single-crystal face indexing with XRD. Using Paracetamol (PCM) form I as a model compound, we demonstrate how preferred orientation effects in PXRD can be used with ARPRS measurements at different sample orientations, obtained by rotating in the plane perpendicular to the laser incidence direction, to define facet assignments from a set of possible planes. PXRD alone cannot distinguish the (011) and (01) facets, but these can be differentiated with ARPRS by analysing the change in normalised band intensity of selected vibrational modes under crystal rotation. Information on the symmetry and orientation of vibrational modes relative to the incident laser can be related to the orientation of functional groups, and this information is consistent with the predicted particle morphology as well as with measurements of the interfacial angle between the facets and corresponding Miller planes.

We here explore how some frequently overlooked computational parameters affect the simulation of phonon frequencies in organic molecular crystals within the framework of density functional perturbation theory in a pseudo-core plane wave basis set. Specifically, we investigate how the density of the Fourier grid that is used to map real-space charge density affects the phonon frequencies and eigenvectors. We find that varying the density of this Fourier grid can affect low-frequency phonons by tens of wavenumbers and significantly alter the associated normal mode eigenvectors. Furthermore, we demonstrate that poorly converged charge density representations can lead to substantial errors in simulated thermodynamic quantities, with vibrational free energies affected by 3–4 kJ mol⁻¹ in certain systems. We show how this variation in predicted free energies can have a significant impact on our ability to correctly predict the relative stability of a series of model polymorphic systems. We finally discuss how careful convergence with respect to the Brillouin zone (q-point) sampling is imperative for the correct modelling of phonon dispersion relations in organic molecular crystals, particularly for systems characterised by weak, anisotropic interactions. Whilst no definitive ‘rules of thumb’ emerge for the convergence of these parameters, our findings highlight the critical role they play in obtaining reliable phonon frequencies from density functional perturbation theory. Our results also offer insight into the potential magnitude of errors that could arise in phonon simulations of organic molecular crystals if these parameters are not chosen carefully.

Crystallography provides a powerful framework for identifying, characterizing, and designing new ionic liquids (ILs) with targeted thermal and structural properties. While the design of imidazolium-based ILs has historically relied on empirical modification of alkyl chain length, cation symmetry, and electronic or steric effects, crystallography reveals how these molecular parameters dictate lattice packing, intermolecular interactions, and ultimately melting behavior. Despite extensive study, critical structure–property relationships remain unresolved, including the impact of C4 and C5 methylation, odd-numbered alkyl chains, and conformational polymorphism. From a crystal engineering perspective, the design of low-melting ionic compounds can be viewed as a deliberate inversion of traditional crystal design principles. Rather than promoting long-range order, researchers aim to disrupt specific noncovalent synthons and reduce lattice enthalpy to favor fluidity. This tutorial review unifies these perspectives by examining how crystallography has helped steer structural design to control interactions, torsion angles, molecular descriptors, and hydrogen-bond networks to modulate the behavior of dialkylated imidazolium salts. The discussion highlights how crystallography transforms the empirical art of IL synthesis into a rational, structure-guided design strategy for next-generation materials.

Lead halide perovskite single crystals (LHPSCs) featuring a grain boundary-free structure exhibit unique optoelectronic properties and attract widespread attention in recent research on perovskites. Depending on shallow defect dominance and low crystalline formation energy, LHPSCs are able to maintain superior crystal quality even in rapid solution growth processes compared to strict growth control for traditional semiconductors. This distinctive crystal fabrication-performance compatibility provides an ingenious opportunity for scaling up perovskite single crystal fabrication from laboratory prototypes to practical applications. Herein, the solution-growth strategies, as well as corresponding crystallization thermodynamics and kinetics of LHPSCs, are first discussed. We further summarize the latest progress in the fast solution growth regulation of LHPSCs and put forward the development perspective based on the current challenges. This study aims to elucidate the regulatory mechanism of crystalline growth rate and advance the fast solution fabrication of high-quality LHPSCs.

Metal–organic frameworks (MOFs) have emerged as one of the most versatile classes of crystalline porous materials, offering unprecedented tunability in composition, topology, and functionality. Driven by the principles of crystal engineering, MOF research has progressed from structural assembly to rational design, enabling meticulous control over framework architecture, pore environments, and functional attributes. This highlight summarizes recent advances in crystal-engineering strategies, including in situ self-assembly, mixed-linker and mixed-metal design, post-synthesis modification and template-assisted synthesis. These techniques collectively empower precise modulation of porosity, surface chemistry and active-site distribution, thereby tailoring MOFs for applications in gas storage, catalysis, sensing, and energy conversion. Furthermore, this highlight outlines the central challenges that continue to constrain the practical deployment of MOFs and discusses emerging directions of future crystal engineering focusing on MOFs.

Cocrystallization technology is a successful application of supramolecular chemistry in improving the performance of materials. Besides, this technology is regarded as a promising and effective approach to tune the properties of energetic compounds, especially for high-energy-density materials. In this work, based on the high energy density and high mechanical sensitivity of the explosive 2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane (CL-20), a cocrystallization method was put forward to decrease its sensitivity and enhance its safety. Based on this principle, a typical insensitive explosive, 4-amino-3,5-dinitro-pyrazole (LLM-116), was selected as a coformer, and a novel CL-20/LLM-116 energetic cocrystal was designed. The CL-20/LLM-116 cocrystal models with component ratios from 10 : 1 to 1 : 5 were established. The cocrystal models were optimized and the physicochemical performances were predicted by the molecular dynamics (MD) method. The results illustrate that among the different cocrystal models, the binding energy for the cocrystal model with a molar ratio of 2 : 1 is the highest at 640.42 kJ mol⁻¹, the non-covalent interactions are strongest, and this model holds the most desirable stability. The insensitive component LLM-116 enhances the trigger bond rupture energy of CL-20 molecules by 2.6–22.4 kJ mol⁻¹ compared to pure CL-20, meaning that the CL-20/LLM-116 energetic cocrystal is less sensitive than CL-20, and when the molar ratio is 2 : 1, the cocrystal model has the highest value of trigger bond strength. The designed CL-20/LLM-116 cocrystal exhibits lower energy density than pure CL-20, but it still maintains high energetic performance, especially for the cocrystal model with a molar ratio from 10 : 1 to 1 : 1. Its energy density is higher than those of octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX) and hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX), implying that the CL-20/LLM-116 energetic cocrystals maintain a high energy density. The main intermolecular interactions existing in the CL-20/LLM-116 energetic cocrystals include hydrogen bonding and van der Waals (vdW) forces.

Fossil fuels remain the primary global energy source, but their finite nature and environmental impact drive the search for renewable alternatives. Biodiesel is a promising candidate, though its oxidative instability limits widespread adoption. This work provides a comprehensive structural and computational analysis of two nitro-substituted azine derivatives to evaluate their potential as biodiesel additives. Single-crystal X-ray diffraction and Hirshfeld surface analysis revealed supramolecular stabilization through C–H⋯O, C–H⋯N, and C–H⋯π interactions, highlighting distinct packing motifs associated with nitro substitution. Topological and electronic descriptors showed that additional nitro and methyl groups reduced reactivity in the gas phase, while in the solid state the molecular energy gap (HOMO–LUMO) remained comparable. Also, a non-centric azine molecular structure exhibited an exceptionally high second-order nonlinear optical response, more than 30-fold higher than centric azine. Machine learning models were employed to predict the oxidation rate constants in the presence of ˙OH radicals and to predict the optical activity parameters. The results indicated a better absorption and emission response for azine with asymmetric electronic distribution and high dipole moment. Predictions of the oxidation rate in the presence of ˙OH radicals indicate superior antioxidant performance for the azine with the fewest nitro groups, with reaction rates comparable to those observed in diesel and the main components of biodiesel. These findings demonstrate that crystal packing, molecular symmetry, and substitution patterns govern both solid-state properties and antioxidant performance, underscoring the value of molecular-based approaches in designing next-generation biodiesel stabilizers.