Crystal Analysis Research Articles

Integration of Wallach's Rule into Intermolecular Charge Transfer: A Visual Strategy for Chiral Purification.

Exploring the molecular packing and interaction between chiral molecules, no matter single enantiomer or racemates, is important for recognition and resolution of chiral drugs. However, sensitive and non-destructive analysis methods are lacking. Herein, an intermolecular-charge transfer (ICT) based spectroscopy is reported to reveal the differences in interaction between the achiral acceptor 1,2,4,5-tetracyanobenzene (TCNB) and the chiral donors, including S, R, and racemic naproxen (S/R/rac-NAP). In this process, S-NAP+TCNB and R-NAP+TCNB display a narrower band gap attributed to the newly formed ICT state. In contrast, the mixed rac-NAP and TCNB exhibit almost no significant change due to the strong affinity between the stereoisomers according to the Wallach's rule. Thus, S/R-NAP can be easily distinguished from rac-NAP based on significantly different optical behavior. The single crystal analysis, infrared spectroscopy, fluorescence spectroscopy, and theoretical calculation of naproxen confirm the importance of carboxyl for this differentiation in molecular packing and interaction. In addition, the esterification derivatization of naproxen achieves the manipulation of the intermolecular interaction model of racemates from the absolute Wallach's rule to a coexisting form of Wallach's rule and ICT. Further, visualized chiral purification of naproxen by the simple cocrystallization method is achieved through the collaboration of ICT and Wallach's rule.

Synthesis, Structure, and Resolution of Functionalized Oxacalix[4]arenes with Planar Chirality via Dynamic SNAr Reaction

A pair of racemic oxacalix[4]arenes featuring planar chirality and a mesomer with a symmetric plane were conveniently synthesized under mild conditions via a one‐pot dynamic SNAr reaction and separated in 20% and 49% yields, respectively. X‐ray single crystal analyses confirmed their structures unambiguously. The racemic mixture could further be resolved using HPLC on a chiral column. Time‐dependent products distribution and interconversion between products with CsF as a catalyst were revealed by 1H NMR studies, convincing the dynamic nature of SNAr reaction.

Effects of Mg and Al doping on the desorption energetics and electronic structure of a Ti-V-Zr-Nb alloy hydride

Refractory high-entropy alloys (HEAs) show promise for novel hydrogen storage technology, but addressing their limited gravimetric hydrogen storage capacity necessitates exploration of light alloying elements including Mg and Al. Here, we employ density-functional theory to investigate the hydrogen desorption energetics of Ti0.325V0.275Zr0.125Nb0.275 alloy and the impact of doping with Mg and Al. Our analysis reveals that Mg and Al addition thermodynamically destabilize the Ti0.325V0.275Zr0.125Nb0.275-hydride and lower its storage capacity. The observed destabilization is attributed to reduced chemical contributions to the desorption enthalpy in the Mg and Al-doped hydrides. Detailed examination of the electronic density of states, electron localization function, and crystal orbital Hamilton population analysis unveils fundamental features of chemical bonding in these hydrides. Notably, H-H antibonding states occur for hydrogen atoms located in the nearest-neighbor interstices of Mg and Al atoms. Charge transfer facilitates formation of these antibonding states. This comprehensive analysis enhances our understanding of the intricate interplay between electronic structure, hydrogen desorption energetics, and chemical bonding in HEA hydrides, offering valuable insights for the design and optimization of advanced hydrogen storage materials.

Evaluating the impact of iron impurities in KOH on OER performance of BaNiO3 single crystals using scanning electrochemical cell microscopy

Understanding the oxygen evolution reaction (OER) electrocatalysis requires a careful understanding of the surface and activity evolution of well-defined materials. An especially promising candidate is the BaNiO3 hexagonal perovskite, matching strides with benchmark catalysts such as Ba0.5Sr0.5Co0.8Fe0.2O3–δ. Here, we conducted a structural and electrochemical analysis of BaNiO3 single crystals to assess the influence of iron impurities in KOH electrolyte on their OER performance. We used scanning electrochemical cell microscopy (SECCM) for precise measurements on BaNiO3 single crystals in the absence of carbon additives. Cyclic voltammetry (CV) revealed that the presence of iron consistently enhanced the OER current with subsequent cycles, indicating a dynamic improvement in BaNiO3's electrochemical activity. Conversely, in iron-free KOH electrolyte, performance diminished with cycling. These findings not only underscore the critical necessity of KOH purification for BaNiO3 electrochemical studies but also showcase SECCM's unparalleled ability to offer insights into the electrochemical evolution of individual entities such as single crystals. This makes it a powerful operando tool for evaluating forthcoming single crystals, thereby aiding in the design of superior catalysts for OER reactions.

Biocatalyst mediated green approach for 1,8-dioxo-octahydroxanthenes: SCXRD, Hirshfeld analysis and DFT studies as inhibitors of HIV reverse transcriptase

AIDS, caused by human immunodeficiency virus (HIV) is persistent on being one among the deadliest disease of all time. It destroys the immune system of the body and there is currently no effective cure for this. In this regard, in continuation to our studies on green catalysts, more efficient, constructive, and environmentally sustainable protocols for the synthesis of xanthene and its derivatives as HIV Reverse Transcriptase inhibitors were developed with the use of biocatalyst via baker's yeast that explores a viable approach on expanding environmental challenges and enlightens the superiority and exclusivity of this protocol. The current approach manifests numerous notable advantages that include ease of preparation, handling and benignity of the catalyst, low cost, green reaction conditions, facile workup, excellent yields (87–96 %) with extreme purity. The title compounds were docked on the crystal structure of a catalytic complex of HIV-1 reverse transcriptase (PDB: 1RTD). The C-score values achieved in the range 6.68–3.05 suggest that docking analysis was propitious signifying the review of all the forces of interaction between the ligand and the protein. The crystal studies and DFT analysis of compound 3d correlate the optimized geometrical features with empirically accessible XRD data.

Electrifying HCOOH synthesis from CO2 building blocks over Cu–Bi nanorod arrays

Precise electrochemical synthesis of commodity chemicals and fuels from CO2 building blocks provides a promising route to close the anthropogenic carbon cycle, in which renewable but intermittent electricity could be stored within the greenhouse gas molecules. Here, we report state-of-the-art CO2-to-HCOOH valorization performance over a multiscale optimized Cu-Bi cathodic architecture, delivering a formate Faradaic efficiency exceeding 95% within an aqueous electrolyzer, a C-basis HCOOH purity above 99.8% within a solid-state electrolyzer operated at 100 mA cm-2 for 200 h and an energy efficiency of 39.2%, as well as a tunable aqueous HCOOH concentration ranging from 2.7 to 92.1 wt%. Via a combined two-dimensional reaction phase diagram and finite element analysis, we highlight the role of local geometries of Cu and Bi in branching the adsorption strength for key intermediates like *COOH and *OCHO for CO2 reduction, while the crystal orbital Hamiltonian population analysis rationalizes the vital contribution from moderate binding strength of η2(O,O)-OCHO on Cu-doped Bi surface in promoting HCOOH electrosynthesis. The findings of this study not only shed light on the tuning knobs for precise CO2 valorization, but also provide a different research paradigm for advancing the activity and selectivity optimization in a broad range of electrosynthetic systems.

Automated Continuous Crystallization Platform with Real-Time Particle Size Analysis via Laser Diffraction.

The fourth industrial revolution is gaining momentum in the pharmaceutical industry. However, particulate processes and suspension handling remain big challenges for automation and the implementation of real-time particle size analysis. Moreover, the development of antisolvent crystallization processes is often limited by the associated time-intensive experimental screenings. This work demonstrates a fully automated modular crystallization platform that overcomes these bottlenecks. The system combines automated crystallization, sample preparation, and immediate crystal size analysis via online laser diffraction (LD) and provides a technology for rapidly screening crystallization process parameters and crystallizer design spaces with minimal experimental effort. During the LD measurements, to avoid multiple scattering events, crystal suspension samples are diluted automatically. Multiple software tools, i.e., LabVIEW, Python, and PharmaMV, and logic algorithms are integrated in the platform to facilitate automated control of all the sensors and equipment, enabling fully automated operation. A customized graphical user interface is provided to operate the crystallization platform automatically and to visualize the measured crystal size and the crystal size distribution of the suspension. Antisolvent crystallization of ibuprofen, with ethanol as solvent and water with Soluplus (an additive) as antisolvent, is used as a case study. The platform is demonstrated for antisolvent crystallization of small ibuprofen crystals in a confined impinging jet crystallizer, performing automated preplanned user-defined experiments with online LD analysis.

Study of the Effects on the Strengthening Mechanism and Wear Behavior of Wear-Resistant Steel of Temperature Controlling in Heat Treatment.

To improve the wear resistance of the materials used for blades in engineering machinery, this study focused on the microstructural characteristics, mechanical properties, and wear behavior of HB500 grade wear-resistant steel developed using an optimized heat treatment system. To improve the temperature uniformity of the heat treatment furnace, the method of cyclic heating was used to heat the components. Carefully designing the quenching equipment, such as using a cross-shaped press, was employed to enhance the quenching effect and reduce the deformation of the steel plates. The crystal orientation analysis revealed a uniform and fine-grained microstructure, primarily characterized by plate-type tempered martensite, which indicated a good hardenability. The microstructure observations showed that the width of martensite is approximately 200 nm, with a significant presence of dislocations and carbides. Tensile tests and multi-temperature gradient impact tests indicated superior mechanical properties compared to similar grade wear-resistant steels, including a Rockwell hardness of 53, tensile strength of 1610 MPa, yield strength of 1404 MPa, and total elongation around 12.7%. The results of friction and wear experiments indicate that the wear rate decreases as the load increases from 100 N to 300 N, demonstrating an excellent wear resistance under a large load. Observations of the worn surfaces indicated that the wear mainly involved adhesive wear, fatigue wear, and oxidative wear. The properties' improvements were attributed to microstructure refinement and precipitation strengthening. This study indicates that designing a heat treatment system to control temperature uniformity and stability is feasible.

Theoretical and experimental demonstration of mononuclear Ni(II) and dinuclear Ni(III) complexes concerning their catalytic activity, DNA/ protein binding efficacy

The successful use of metal complexes in enzyme catalysis and biomedical applications boosts researchers to develop more and more metal-based compounds to inspect their said applications.In the present work one novel mononuclear Ni(II) [Ni(L1)2] (1) and one di nuclear Ni(III) complexes [Ni(L2)2(N3)2] (2) have been developed by utilizing N2O donor Schiff base ligand HL1 and N2O2 donor Schiff base ligand H2L2 respectively. The single crystal data analysis reveals that in complex 1 two deprotonated ligands coordinate to the Ni(II) forming a distorted octahedral geometry. The asymmetric unit of complex 2 comprises one deprotonated ligand (both the protons of phenolic –OH group were deprotonated), one azide anion, and one Ni(III). Two Ni(III) centers are connected via phenoxide bridging. Followed by the structural analysis the UV spectroscopic study is performed to understand the catecholase-like activity of the developed complexes by using 3,5-di-tertbutyl catechol (3,5-DTBC). The calculated turnover numbers (Kcat) for both complexes disclose the fact that complex2 is more susceptible to this catalytic process than 1. During the catalysis process, the production of Ni(II) in the case of complex2is favorable and this is the main factor to show its higher susceptibilitytowards the catalytic process. The biomedical applicability in terms of anticancer and antibacterial of complexes 1 and 2 is assessed by evaluating their interaction ability with DNA and HSA with the help of several spectroscopic approaches. The remarkably high complex-macromolecules binding constant values, obtained from electronic titration approve the binding efficacy of the target complexes (order ∼ 105). But if a tiny comparison is done then it is seen that complex 2 shows better DNA and HSA binding efficacy. The theoretical approach using molecular docking study fully validates the experimental findings.

In situ X-ray absorption spectroscopy using the FAME autoclave: a window into fluid-mineral-melt interactions in the Earth’s crust

ABSTRACT We discuss the X-ray absorption spectroscopy (XAS) methods elaborated using the high pressure and high-temperature autoclaves installed at FAME and FAME-UHD beamlines. These methods are based on the in situ acquisition of X-ray transmission and fluorescence spectra of hydrothermal fluids and silicate melts and enable the derivation of both solubility and speciation information about metal complexes. The technological assets of our autoclaves are described across a wide range of experimental conditions spanning from different types of hydrothermal fluids, from liquid-like to vapor-like densities having metal concentrations of <1–10,000 ppm, to magmatic fluid-melt systems at 1000°C. Scientific examples are presented to illustrate the use and the advantages of our spectroscopic ‘micro-batch’ reactors. Finally, the integration of our autoclave setups on the FAME-UHD crystal analyzer spectrometer and the benefits of this technique are demonstrated.

Significantly enhanced crystallization of poly(L‐lactide) by incorporation of poly(D‐lactide) grafted cellulose nanocrystals

AbstractPoly(L‐lactic acid) (PLLA), as a green, biodegradable polymer material, has garnered considerable attention due to its ease of processing and exceptional properties. However, the inherent slow crystallization rate and brittleness of PLLA substantially restrict its extensive applications across various domains. In present work, PLLA and poly(D‐lactide) (PDLA)‐modified cellulose nanocrystals (CNCs), referred as CNC‐g‐L and CNC‐g‐D, are serving as nano‐fillers to enhance the crystallization rate of PLLA. Our findings demonstrate that both nano‐fillers could enhance the crystallization rate of PLLA, but the CNC‐g‐D shows a more efficient nucleation agent compared with its counterpart, CNC‐g‐L. Isothermal crystallization analysis indicates that CNC‐g‐D substantially increases nucleation density of PLLA, with pronounced crystallization at an elevated temperature of 155°C as confirmed by differential scanning calorimetry (DSC) and polarized optical microscopy (POM). Wide‐angle x‐ray diffraction (WAXD) analysis shows the preformation of stereocomplex crystals on the CNC‐g‐D surface may result in a fast crystallization rate. Meanwhile, after incorporation of different nano‐fillers, the toughness property of PLLA has also been significantly enhanced. Our result has shown the CNC‐g‐D could serve as an efficient nucleation agent toward PLLA and also facilitate to aiding in establishing comprehensive structure–property relationships of polymer materials.

On Klein tunneling of low-frequency elastic waves in hexagonal topological plates

Incident particles in the Klein tunnel phenomenon in quantum mechanics can pass a very high potential barrier. Introducing the concept of tunneling into the analysis of phononic crystals can broaden the application prospects. In this study, the structure of the unit cell is designed, and the low frequency (< 1 kHz) valley locked waveguide is realized through the creation of a phononic crystal plate with a topological phase transition interface. The defect immunity of the topological waveguide is verified, that is, the wave can propagate along the original path in the cases of impurities and disorder. Then, the tunneling phenomenon is introduced into the topological valley-locked waveguide to analyze the wave propagation, and its potential applications (such as signal separators and logic gates) are further explored by designing phononic crystal plates. This research has broad application prospects in information processing and vibration control, and potential applications in other directions are also worth exploring.

Synthesis, Studies of Inorganic Class of Mohrite (MOH) Crystals for Electrical, Electronic, Photonic, Phase Matching and Sensor Utilities by Theory and Practice

The high-quality single crystals of Mohrite (MOH) with dimensions 7 × 6 × 3 mm3 were productively grown-up by the customary solution growth methodology. The fully grown crystals were focused to the appropriate structural, optical and electrical investigations. The MOH is monoclinic nature of the specimen with P21/c as the space group and lattice parameters are a as 6.2385 Å, b as 12.6076 Å, c as 9.2655 Å and beta is 106.526°. The crystalline structural authentication with single crystal XRD analysis and compared the same with software based associated results. FITR spectra reveal the vibrational modes of as grown crystals. Optical absorption spectral data divulges that the as-grown crystalline sample has higher optical transparent nature in the visible-NIR region. Photoluminescence intensity is remarkably enriched, shows high crystallinity of MOH. The results of UV, PL, electrical and photo conductivity, SEM, theoretical studies suggest MOH in photonic utility and device appliances especially in UV filters and in electronic filters, room temperature based sensor study for MOH is enabled and reported for red LED based work.

Sustainable biodiesel production via castor oil transesterification using organotin(IV) compounds as catalysts

The rapid reduction in fossil fuel reserves and their environmental effects has caused a serious threat to humanity. Meanwhile, the exponential increase in the usage of fossil fuels demands the exploration of new energy sources. Therefore, this work was designed keeping in view the today need of the World for renewable energy source. The 4-(4-chloro-2-fluorophenylamino)-4-oxobut-2-enoic acid based organotin(IV) carboxylates were prepared and characterized by FT-IR, NMR and single crystal XRD analysis. Due to the Lewis acid character of Sn(IV) centre confirmed by DFT computational study, the synthesized compounds were used as catalysts for the transesterification of castor oil for biodiesel production. Under the optimized experimental conditions, the catalytic performance of the tested compounds was found as follow: 1 > 3 > 2 > 4 > 6 > 5 > 7. The obtained biodiesel was confirmed by FT-IR, NMR and GC–MS. The fuel properties of the obtained biodiesel were also determined and compared with American Standard (ASTM D-6751). Based on their catalytic performance, these compounds might be the potential future candidates for the expansion of catalyst systems for efficient biodiesel production from the various feedstocks.

Modeling and Crystal Plasticity Analysis of Strain Hardening in Metallic Materials under the Influence of Microstructure

Modeling and Crystal Plasticity Analysis of Strain Hardening in Metallic Materials under the Influence of Microstructure

Crystal Structure Parameter Analysis of Reduced Graphene Oxide (rGO) from Coconut Shell Charcoal

In this research, reduced graphene oxide (rGO) material from coconut shell charcoal was synthesized using the modified Hummer method. The reduction process of Graphene Oxide (GO) to rGO uses the reducing agent L-Ascorbic Acid (LAA) and is assisted by microwave radiation. The samples obtained were then characterized using XRD to analyze the crystal structure parameters of the rGO samples obtained. Based on the XRD results, the data obtained was then analyzed using the Scherrer and modified Scherrer equations to determine the crystal size in the sample. In addition, the Williamson-Hall equation is also used to analyze crystal size and lattice strain. This article also analyzes XRD data using the Rietveld method using Rietica software. The output from the Rietica software obtained lattice parameter values a ≠ b ≠ c and angle α = β = γ = 90° which indicates an orthorhombic crystal lattice structure. In the refinement process, Rietica's software affects the suitability parameters in the form of R and GOF indicator values. The sample obtained was also measured for the electrical conductivity value of the rGO sample using an LCR meter.

Green synthesis of Carica papaya mediated silver nanoparticles: Characterization, antibacterial activity, and bioelectricity generation for sustainable applications in nanotechnology

This study presents a sustainable method for synthesizing silver nanoparticles (Ag NPs) using green Carica papaya extract (CPE) as a reducing and stabilizing agent. The green synthesis minimizes environmental impact and utilizes bioactive compounds in Carica papaya (CP), offering an economical and sustainable alternative. The goal is to employ CPE for the eco-friendly synthesis of Ag NPs, followed by comprehensive characterization, antibacterial evaluation, cytotoxicity against brine shrimp, and examination of bioelectricity generation. Locally sourced CP was boiled in deionized water, then cooled and filtered twice. The bio-reduction of silver ions to Ag NPs was confirmed by a color change when 45 mL of 0.005 M AgNO3 was mixed with 5 mL of CPE. Characterization through UV–vis absorption spectrophotometry (UV), X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), Field emission scanning electron microscopy (FESEM), Energy dispersive X-ray spectroscopy (EDX), Transmission electron microscopy (TEM), and Gas chromatography-mass spectrometry (GC–MS) analysis confirms the successful formation and consistent size distribution of Ag nanoparticles. CPE is a crucial reducing agent, as evidenced by a distinct UV-visible peak at 422 nm. X-ray crystal analysis verifies highly crystalline Ag NPs with a face-centered cubic lattice structure. The d-spacing values in SAED images are consistent with the results obtained from XRD. Antimicrobial effectiveness against Escherichia coli and Staphylococcus epidermidis is demonstrated. The study explores the bioelectricity generation potential of CPE-synthesized Ag NPs, indicating promising prospects for sustainable energy solutions. Preliminary experiments show the ability of the nanoparticles to catalyze bio-electrochemical reactions. This dual-benefit study underscores CPEs role in antibacterial properties and bioelectricity generation, laying the groundwork for further research in sustainable nanotechnology applicable to healthcare and energy sectors and contributing to the advancement of environmentally friendly technologies.

A Review: Graphene Photonic Crystal Fiber

Next-generation optical fibers with diverse operating mechanisms, high functionality, and a porous structure that may be designed are known as photonic crystal fibers, or PCFs. In the meantime, two-dimensional graphene, possessing incredibly unique characteristics, is a perfect material for optoelectronic and optical uses. Recently, many studies have been published based on the integration of graphene with PCFs to create a new graphene PCF (Gr-PCF). There hybrid fibers show outstanding light-mater interaction over a broad spectrum range. This review starts with general introduction about photonic crystal fiber and analysis of optical properties. This is followed by a Plasmonic PCF then Graphene and physico-chemical properties of graphene nanomaterials. The review primarily covers the introduction of graphene and PCFs with many Applications including Optics Communications and different physical sensors.

Exploring magnetic space groups of [formula omitted] MXene and its connection to vibrational and electronic properties

The vibrational, electronic, and magnetic properties of two-dimensional Cr2N MXene were investigated. Two crystal cells (hexagonal and monoclinic) were considered with their respective magnetic space groups. In the absence of experimental data to fine-tune the Ueff (Hubbard correction), we utilized cell parameters and magnetic moment as a reference window, derived from meta-GGA calculations performed with the SCAN functional. A value of Ueff (1.25 eV) was determined, which does not overestimate the lattice parameters and magnetic moment values. Phonon scattering was calculated, and the vibrational modes were indexed. According to the density of states, the observed splitting in the eg and t2g orbitals, and the crystal field analysis, we deduce that chromium in the MXene Cr2N predominantly adopts an octahedral coordination environment, a combination of octahedral and tetrahedral coordination results in the splitting of the d orbitals. Finally, using Monte Carlo simulation, the critical temperature (Tc) for each space group with different functionals was obtained.

Zirconium-Based Metal-Organic Frameworks with Free Hydroxy Groups for Enhanced Perfluorooctanoic Acid Uptake in Water.

Perfluorooctanoic acid (PFOA) is a highly recalcitrant organic pollutant, and its bioaccumulation severely endangers human health. While various methods are developed for PFOA removal, the targeted design of adsorbents with high efficiency and reusability remains largely unexplored. Here the rational design and synthesis of two novel zirconium-based metal‒organic frameworks (MOFs) bearing free ortho-hydroxy sites, namely noninterpenetrated PCN-1001 and twofold interpenetrated PCN-1002,are presented. Single crystal analysis of the pure ligand reveals that intramolecular hydrogen bonding plays a pivotal role in directing the formation of MOFs with free hydroxy groups. Furthermore, the transformation from PCN-1001 to PCN-1002 is realized. Compared to PCN-1001, PCN-1002 displays higher chemical stability due to interpenetration, thereby demonstrating an exceptional PFOA adsorption capacity of up to 632mgg-1 (1.53mmolg-1), which is comparable to the reported record values. Moreover, PCN-1002 shows rapid kinetics, high selectivity, and long-life cycles in PFOA removal tests. Solid-state nuclear magnetic resonance results and density functional theory calculations reveal that multiple hydrogen bonds between the free ortho-hydroxy sites and PFOA, along with Lewis acid-base interaction, work collaboratively to enhance PFOA adsorption.