CrystEngComm最新文献

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.

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.

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.

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.

Copper materials with nanoplate structure combine the advantages of nano and micrometer dimensions, featuring excellent electrical conductivity, low-temperature sintering performance, and processability. They have considerable applicability and greater economic benefits compared with silver, and thus have attracted much attention in the field of microelectronic packaging. In this study, a seed-mediated growth method was proposed to synthesize copper nanoplates (Cu NPs) under mild conditions. By selecting pre-synthesized silver nanoplates as seeds, the synthetic efficiency and dimensional controllability of Cu NPs have been greatly improved. At 40 °C, Cu NPs with good dispersion can be obtained within 15 min. The formation mechanism of Cu NPs was proposed by studying the factors that influence it. The conductive adhesives formulated with as-synthesized Cu NPs achieve an impressively low resistivity of 35 μΩ cm at a filler content of 90 wt%, paving the way for the industrial application of copper-based conductive adhesives.

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.

We here report the synthesis of 2D perovskites based on highly fluorinated organic cations (LF8 and SMS28) that impart high hydrophobicity and thermal stability to the resulting materials. Stability tests showed that 2D perovskites (SMS28)₂PbI₄ and (LF8)₂PbI₄ maintained their structural properties unchanged for over a month of exposure to 75% relative humidity (RH), demonstrating high resistance to severe environmental conditions. When applied as top layers on films of a typical 3D perovskite (MAPbI₃) employed in photovoltaic cells, these fluorinated 2D materials slowed down the structural deterioration processes triggered by water infiltration as compared to unprotected samples, even at high RH conditions. The results highlight the potential of these coatings as a hydrophobic barrier to increase the environmental stability of common 3D perovskites, offering the possibility of improving the long-term protection of moisture-sensitive materials.

Au@Pd@Pt core–shell nanoparticles (CSNs) with mesoporous structures and nanocavities were synthesized through a seed-mediated growth method. The process involved the initial formation of Au@Pd CSNs via the reduction of PdCl₄²⁻ by ascorbic acid (VC), followed by a reduction of PtCl₆²⁻ by VC, and a galvanic replacement reaction between the Pd shell and PtCl₆²⁻. The galvanic replacement reaction is a critical step in the formation of Au@Pd@Pt CSNs featuring distinctive voids in the mesoporous structures. The electrocatalytic performance of the as-synthesized Au@Pd@Pt CSNs for the ethanol oxidation reaction (EOR) was systematically evaluated. Due to the unique hierarchical structure featuring both mesoporosity and internal nanocavities, Au@Pd@Pt CSNs exhibited significantly enhanced electrocatalytic activity compared to Au@Pd CSNs, Au@Pt CSNs, and commercial Pd/C catalysts. This work presents a facile strategy for constructing hierarchical core–shell nanostructures, demonstrating considerable potential for application in electrocatalytic ethanol oxidation.