Arrangement In Crystal Lattice Research Articles

A new mixed-ligand mononuclear Co(II) complex derived from 4,4,4-trifluoro-1-phenylbutane-1,3-dione and 1,10-phenanthroline: Synthesis, structural elucidation and quantum-computational studies

In this study, a novel mixed-ligand mononuclear Co(II) complex, denoted as {[Co(TFPBD)2(PHE)]DMF}, was synthesized and characterized using single crystal X-ray diffraction analysis. The central cobalt atom coordinated with two 4,4,4-trifluoro-1-phenylbutane-1,3-dione ligands (TFPBD1 and TFPBD2) and a 1,10-phenanthrene (PHE) ligand, adopting a slightly distorted octahedral geometry. Notably, the non-planar characteristics of the ligands led to the manifestation of non-covalent interactions within the molecular structure, further enhanced by the involvement of the lattice DMF solvent. The crystal lattice arrangement in the {[Co(TFPBD)2(PHE)]DMF} complex was a result of diverse non-covalent interactions, including hydrogen bonds, C-F…π, and Π…π stacking interactions, influenced the crystal's stability. Additionally, the study delved into the unique lattice arrangement consisted of pairwise R12(5) ring motifs along with one-dimensional molecular arrays formed along the crystallographic axes. Furthermore, intermolecular C-F…π Cg…Cg interactions resulting in two-dimensional linear molecular arrays along the a- and b-axes. Quantum computational studies using density functional theory (DFT) were employed to examine the complex's electronic structure and stability and reactivity, highlighting electron-rich and electron-deficient regions. Hirshfeld surface analysis (HSA) and Non-covalent interaction analysis confirmed the significance of intermolecular interactions where 2D fingerprint plots emphasized the prominence of CH…F interactions within the crystal structure. These findings contribute significantly to our understanding of mixed-ligand metal complexes and their potential applications in various scientific domains.

Dielectric Spectroscopy of Calcium Titanate Processed by Spark Plasma Sintering.

Calcium titanate (CaTiO3) powder was compacted by spark plasma sintering (SPS). The resulting products were subjected to the phase stability study and dielectric characterization. The change in temperature of SPS between 1100 °C and 1250 °C had a clear and straightforward effect on density, porosity, relative permittivity, loss tangent, and DC resistivity. Since the SPS itself introduces certain oxygen deficiency into Ti-perovskites, all samples were annealed after SPS. However, this post-processing did not mask the effects of the SPS regime. Optical reflectance measurements were completed to compare and quantify the sample coloration and support the dielectric results with corresponding optical band gap estimations. Subtle changes in the CaTiO3 crystal lattice arrangement, completed between 1150 °C and 1250 °C and documented in the literature for conventionally sintered samples, could not be confirmed for SPS-prepared calcium titanate. The novelty of this research work is in producing very stable dielectric ceramics and an indication of the SPS processing parameters suitable for this. The best sample showed at 1 MHz frequency the combination of relative permittivity 370, loss tangent 0.008, and DC resistivity 3 × 1012 Ωm.

Structure-property relations of a unique and systematic dataset of 19 isostructural multicomponent apremilast forms.

The structure-property relations are examined for apremilast cocrystals and solvates in this work. A unique and large dataset of multicomponent crystal forms is presented including 7 cocrystals and 12 solvates. In total, 15 of the presented multicomponent forms and their crystal structures are published here for the first time. This dataset is unique owing to the extreme crystal packing similarity of all 19 crystal forms. This fact makes the evaluation of structure-property relations significantly easier and more precise since the differences in the crystal lattice arrangement are close to negligible. Properties of the guest molecules used here can be directly correlated with the macroscopic properties of the corresponding multicomponent forms. Interestingly, a considerable correlation was found between the intrinsic dissolution rate of the multicomponent forms and their solubility, as well as the solubility of their guest molecules in the dissolution medium. The latter is of particular interest as it can aid in the design of multicomponent forms with tuned properties.

Characterizations of Single-Crystal Lithium Niobate Thin Films

Single-crystal lithium niobate thin films (lithium niobate on insulator, LNOI) are becoming a new material platform for integrating photonics. Investigation into the physical properties of LNOI is important for the design and fabrication of photonic devices. Herein, LNOIs were prepared by two methods: ion implantation and wafer bonding; and wafer bonding and grinding. High-resolution X-ray diffraction (HRXRD) and confocal Raman spectroscopy were used to study the LNOI lattice properties. The full-width at half-maximum (FWHM) of HRXRD and Raman spectra showed a regular crystal lattice arrangement of the LNOIs. The domain inversion voltage and electro-optical coefficient of the LNOIs were close to those of LN bulk material. This study provides useful information for LNOI fabrication and for photonic devices in LNOI.

Physico-chemical and biological responses for hydroxyapatite/ZnO/graphene oxide nanocomposite for biomedical utilization

Bioceramics, graphene oxide, and metal oxide-based biomaterials are intriguing prospects for hard tissue biomedical applications. Combining hydroxyapatite (HAP), graphene oxide (GO), and Zinc oxide (ZnO) to fabricate HAP/ZnO/GO nanocomposite presented a noticeable improvement in bioactivity biocompatibility and antimicrobial activity. The crystal lattice changes and structural arrangement of these nanocomposites are examined using XRD, TEM, and SEM. Moreover, the GO nanosheets, HAP, and ZnO bonding are reported in FTIR and XPS spectra. The TEM micrographs showed the nanocomposite structural alteration and revealed the uniformity of HAP and ZnO distribution into GO nanosheets with 10 nm in diameter and length of 25 nm. Furthermore, the SEM scan explained the porosity and integrated structure that showed a size of 0.3–1.4 μm. HAP/ZnO/GO roughness average reached 40.2 nm. The cell viability test for the nanocomposite revealed a high value of 99.5 ± 1.5%. The antibacterial property of HAP/ZnO/GO was confirmed with the reported inhibition zone of 20.4 ± 1 mm and 15.3 ± 1.1 mm against E. coli and S. aureus. Herein, combining HAP and ZnO with GO nanosheets alters morphological features and enhances roughness parameters of the fabricated nanocomposite. Besides structural porosity, cell adhesion and bioactivity improved. The resulting porous reinforced nanocomposite that showed excellent antibacterial activity is a biomaterial of interest in bone replacement utilization.

Hybrid mono-crystalline silicon and lithium niobate thin films [Invited

The heterogeneous integration of silicon thin film and lithium niobate (LN) thin film combines both the advantages of the excellent electronics properties and mature micro-processing technology of Si and the excellent optical properties of LN, comprising a potentially promising material platform for photonic integrated circuits. Based on ion-implantation and wafer-bonding technologies, a 3 inch wafer-scale hybrid mono-crystalline Si/LN thin film was fabricated. A high-resolution transmission electron microscope was used to investigate the crystal-lattice arrangement of each layer and the interfaces. Only the H-atom-concentration distribution was investigated using secondary-ion mass spectroscopy. High-resolution X-ray-diffraction ω–2θ scanning was used to study the lattice properties of the Si/LN thin films. Raman measurements were performed to investigate the bulk Si and the Si thin films. Si strip-loaded straight waveguides were fabricated, and the optical propagation loss of a 5-µm-width waveguide was 6 dB/cm for the quasi-TE mode at 1550 nm. The characterization results provide useful information regarding this hybrid material.

CO-CRYSTALS OF ACTIVE PHARMACEUTICAL INGREDIENT-IBUPROFEN LYSINE

Objective: Co-crystal is defined as a crystalline complex of two or more neutral molecules bound together primarily by hydrogen bonding or other non-covalent interactions. The pharmaceutical co-crystal involves crystal lattice arrangement between an Active Pharmaceutical Ingredient (API) with another pharmaceutically acceptable molecule. Co-crystals of API are preferred since they depict improved solubility, dissolution, stability, compressibility in comparison with API. Ibuprofen lysine (IL), frequently used analgesic and the anti-inflammatory drug has poor aqueous solubility and compressibility. This work shows the feasibility and optimal conditions for the preparation of co-crystals of ibuprofen lysine using Polyvivylpyrrolidone K25 (PK 25) and Polyvivylpyrrolidone K30 (PK 30) as co-formers.
 Methods: In this study, we prepared and studied the solubility, drug content, flow properties, physical stability of novel co-crystal, consisting of IL and PK 25/PK 30. The co-crystal IL: PK 30 (at a molar ratio of 0.29:0.5) and IL: PK 25 (at a molar ratio of 0.58:1) were characterized by X-ray analysis, infrared spectroscopy and thermal analysis. Furthermore, the tablet formulations of the co-crystals were subjected to in vitro dissolution and in vivo analgesic activity, with the goal of comparing the co-crystals with IL and the marketed tablet of ibuprofen (Brufen®) respectively.
 Results: The IL: PK co-crystals demonstrated superior solubility and the dissolution properties over IL. The compression properties of the co-crystals were similar to IL. The co-crystals exhibited higher analgesic activity than the marketed tablet. 
 Conclusion: The results indicated the use of PK 25 and PK 30 as safe and promising co-crystal formers.

Phytochemical Reduction of Heavy Metal Ion Cd <sup>2+</sup> to Stable CdO Using Ethanolic Extract of <i>Limonia acidissima</i> Leaves and Antimicrobial Investigation Thereof

Secondary metabolites from plants are used for various applications including pharmaceutical, dye degradation and metal reduction. The major reasons for the application of secondary metabolites in these fields are the low cost, surplus resource and biocompatibility. In this research, we have used the phenolic compounds of Limonia acidissima for the reduction of heavy metal cadmium from its salt state (CdSO4) into its metallic oxide state and tested its anti-microbial potency. The secondary metabolites of Limonia acidissima themselves possess anti-microbial activity against gram negative bacteria. The phenolic compounds are also capable of reducing the metallic salts into metal oxides with the transfer of electrons and functionalize the surface of the particles. Thus the ethanolic extract of L.acidissima was used to synthesize CdO nanoparticles by colloidal precipitation method. The synthesized nanoparticles were characterized using XRD for crystal lattice arrangement and FE-SEM for the size and shape of the nanoparticles. The antimicrobial activity of the nanoparticles was compared with the antimicrobial potency of the plant extract and was found to be increased on the introduction of nanoparticles. This work thus provides the anti-bacterial and heavy metal reduction wealth from the effluent and agrowaste.

THERMAL CHARACTERISTIC EVALUATION OF DIFFERENT ASCORBIC ACID CRYSTAL HABITS

Melting temperature (Tmelt) and enthalpy of fussion (ΔHf ) are important parameters to determine the quality and the thermal stability of active pharmaceutical ingredient (API) crystals. In this study, different habit of ascorbic acid was prepared by using different polar solvents namely water, methanol, ethanol and 2-propanol. Ascorbic acid crystal was then been physically and thermally characterised by using microscopic analysis, thermo gravimetric analysis (TGA) and differential scanning calometry analysis (DSC). This provides an insight into the formation of crystal habit across four different polar protic solvents. The ascorbic acid is found to grow as a cubic or prism crystal when grown in water that provides high hydrogen bond between solvent and solute. As the polarity of the solvents decrease, the hydrogen bond weaken and the width of the crystal become narrower, forming almost a needle like crystal. The thermal stability of ascorbic acid crystal is found to be the most stable when ascorbic acid is crystallized from water (prism) and the weakest from 2-propanol (needle) due to the molecule arrangement in crystal lattice in which resulted from decreasing intermolecular forces in the liquid phase

Luminescence Thermochromism of Gold(I) Phosphane-Iodide Complexes: A Rule or an Exception?

A series of gold(I) iodide complexes 1-11 have been prepared from di-, tri-, and tetraphosphane ligands. Crystallographic studies reveal that the di- (1-7) and tetrametallic (11) compounds feature linearly coordinated gold(I) ions with short aurophilic contacts. Their luminescence behavior is determined by the combined influence of the phosphane properties, metal-metal interaction, and intermolecular lattice-defined interactions. The proposed variable contribution of 3 (X+M)-centered (X=halogen; M=metal) and 3 XLCT (halogen to ligand charge transfer) electronic transitions into the lowest lying excited state, which is influenced by supramolecular packing, is presumably responsible for the alteration of room-temperature emission color from green (λ=545 nm, for 11) to near-IR (λ=698 nm, for 2). Dinuclear compounds 6 and 7 exhibit distinct luminescence thermochromism with a blueshift up to 5750 cm-1 upon cooling. Such dramatic change of emission energy is assigned to the presence of two coupled triplet excited states of 3 ππ* and 3 (X+M)C/3 XLCT nature, the presence of which depends on both molecular structure and the crystal lattice arrangement.

Surface modification of LiNbO3 and KTa1−xNbxO3 crystals irradiated by intense pulsed ion beam

In this work, we studied the surface modification of LiNbO3 and KTa1−xNbxO3 irradiated by intense pulsed ion beam, which was mainly composed of H+ (70%) and Cn+ (30%) at an acceleration voltage of about 450kV. The surface morphologies, microstructural evolution and elemental analysis of the sample surfaces after IPIB irradiation have been analyzed by scanning electron microscope, atomic force microscope, X-ray diffraction and energy dispersive spectrometer techniques, respectively. The results show that the surface morphologies have significant difference impacted by the irradiation effect. Regular gully damages range from 200 to 400nm in depth appeared in LiNbO3 under 2J/cm2 energy density for 1 pulse, block cracking appeared in KTa1−xNbxO3 at the same condition. Surface of the crystals have melted and were darkened with the increasing number up to 5 pulses. Crystal lattice arrangement is believed to be the dominant reason for the different experimental results irradiated by intense pulsed ion beam.

Influence of crystal anisotropy on subsurface damage in ultra-precision cylindrical turning of CaF2

An optical microcavity, which stores light at a certain spot, is an essential component to realize all-optical signal processing. Single-crystal calcium fluoride (CaF2) theoretically shows a high Q-factor which is a desirable optical property. The CaF2 microcavity can only be manufactured by ultra-precision cylindrical turning (UPCT). The authors have studied UPCT of CaF2 and shown the influence of crystal anisotropy and tool geometry on surface roughness and subsurface damage. The study indicated that a smaller nose radius of the cutting tool led to shallower subsurface damage. Thus, it is inferred that a smaller nose radius compared to the previous nose radius (0.05mm) can further reduce subsurface damage. Nevertheless, the mechanism that causes a difference in subsurface damage due to crystal anisotropy is not sufficiently clear. The influence of subsurface damage on microcavity performance is still unclear. In this study, the UPCT of CaF2 was conducted using a tool with a nose radius of 0.01mm. The subsurface damage was investigated by transmission electron microscope (TEM) observation from the viewpoint of the change in crystal lattice arrangement. In our previous study, fast Fourier transfer (FFT) analysis was used for confirmation of change of crystal structure. In this study, FFT analysis was also used to quantitatively evaluate the depth of subsurface damage. In addition, inverse fast Fourier transfer (IFFT) was used to analyze change of crystal lattice arrangement clearly, which enables discussion of the influence of slip systems. Finally, optical microcavities are manufactured without any crack, and the influence of subsurface damage on microcavity performance is experimentally evaluated using a wavelength tunable laser and power meter.

Co-Processed Excipients for Tabletting

Tablets and capsules are more popular dosage forms have many advantages include more patient compliance, light, compact, easy and inexpensive manufacturing, high stability and accurate dose administration. The various problems associated with the formulation of tablets can be overcome by incorporation of suitable excipients. The excipients have now their own well defined role in a formulation. To gain better tablet properties, it is necessary to develop new excipients. But it requires a lot of money and regulatory terms, and all required characteristics could not be expected from a single excipient material. So there came an option of combining the existing excipients. This was found to be an excellent method of developing new excipients with desirable properties but there were chances of interference of properties of both the excipients which results in a negative effect. This led to the search of new processes for developing excipients with improved functionalities called particle engineering and co-processing. To create a new excipient, a design of the particle should be created first. The crystal lattice arrangement of the particle is well studied and then the various parameters are changed one by one to find the best excipient with excellent properties resulted in development of single-bodied excipient combination at a sub particle level, called as ‘co-processed excipients’. It is based on the concept of interacting two or more excipients at sub particle level. This process helps to mask the undesirable characteristics of individual excipients and at the same time improve the desirable properties. The chemical structure of excipients remained intact during this process. The idea of co-processed excipients is a part of developing excipients by retaining only their good properties. This can be understood from the large number of co-processed excipients that are marketed. But still there is need of deep investigation into the field. A solution should be found out for the problem of non inclusion of these in official pharmacopoeias.

Development of selective DprE1 inhibitors: Design, synthesis, crystal structure and antitubercular activity of benzothiazolylpyrimidine-5-carboxamides

Decaprenylphosphoryl-b-d-ribose 20-epimerase (DprE1) is a potential drug target for development of antitubercular agents. Structure based drug discovery approach yielded twenty novel derivatives of benzothiazolylpyrimidine-5-carboxamides (7a–t) which were synthesised by three component one pot reaction involving benzothiazolyl oxobutanamide, thiourea and substituted aromatic benzaldehydes. These derivatives were evaluated for antitubercular activity to determine MIC and compound 7a, 7e, 7f and 7o were found to be potentially active against Mycobacterium tuberculosis (H37Rv). Log P of these compounds was found to be between 2.0 and 3.0 making them suitable for oral dosing. DprE1 selectivity and pharmacokinetic studies were carried out for these compounds of which 7a and 7o were found to be highly selective and bioavailability was found to be above 52% by oral dose. Crystal structure of 7a was studied and molecular packing was determined, it exhibited a triclinic crystal lattice arrangement having hydrogen bonded dimeric arrangement. Drug receptor interactions were studied which exhibited docking in the active site of receptor with hydrogen bonding, hydrophobic interactions, vdW interactions with amino acid residues such as Cys387, Asn385, Lys418, Tyr314, Gln334 and Lys367 respectively. 3D QSAR analysis was carried out by kNN-MFA method to determine and develop theoretical model, best suitable model was found to be based on Simulated Annealing k-Neariest Neighbour Molecular Field Analysis (SA kNN-MFA). The model provided with hydrophobic descriptors in positive side indicating the need of bulky groups, steric and electronegative descriptors in negative coordinates hints with contribution by the electronegative substitutions as favourable and desirable moieties for enhancing the activity. The q2, q2_se and Pred_r2se were found to be 0.5000, 0.6404 and 1.0094 respectively. A pharmacophore model was generated which suggested for necessity of aromatic, aliphatic carbon centre and hydrogen bond donor for development of newer DprE1 selective inhibitors.

The effect of electron beam treatment on hydrogen sorption ability of commercially pure titanium

The surface morphology and the microstructure of commercially pure titanium specimens subjected to electron beam treatment with energy density varying from 12 to 25J/cm2 were studied using atomic force microscopy and transmission electron microscopy as well as X-ray diffraction analysis. Lamellar α-phase structure of a thin surface layer of the specimens resulted from the treatment was shown to have a great effect on hydrogen sorption ability of the material as well as on hydrogen arrangement in titanium crystal lattice.

Analyzing the Modality of Two-Dimensional Photonic Crystal Fiber Optical Micro-Resonators by Equivalent Refractive Index Mode

This paper analyzes the modality of two-dimensional photonic crystal micro-resonators by adopting equivalent refractive index mode. In this paper, it controls the optical field distribution only through altering the thickness of light guide layer, while the parameter like resonator structure and crystal lattice arrangement remain stable. It discusses that it would arrive at a satisfactory photon locality while the refractive index of light guide layer material is gallium nitride , the thickness of light guide layer is and its equivalent refractive index is 2.1.This reveals the influence of micro-resonator light guide layer’s thickness towards the modality, providing a preferable pre-estimate method for the actual research of micro-resonators with higher quality.

Synthesis, structure and dielectric properties of the first 1D Ba-tetrazole complex [Ba(4-TPA)2(H2O)4·3.5(H2O)

Abstract The first 1D Ba(II)-tetrazole coordination polymer, [Ba(4-TPA)2(H2O)4·3.5(H2O)]n (1), which is constructed by a [BaO2]n inorganic skeleton chain with organic 4-TPA wings on both sides, has been synthesized and characterized by single crystal X-ray crystallography and temperature dependence dielectric constant (e) measurement, (4-TPA = 2-(4-(1H-tetrazol-5-yl)pyridinium-1-yl) acetate). The e of single crystal sample is almost twice the e of powder sample. However, the dielectric loss of the crystal is relatively smaller, which is attributed to the highly ordered arrangement in crystal lattice.

Kinetic and structural characteristics of niobium vanadium oxide electrodes for secondary lithium batteries

Kinetic study of the insertion process of Li + ions into the crystal lattices of Nb 2− n V n O 5 ( n=0.50 and 0.70) was performed by using current pulse methods as well as an X-ray diffraction study of the structural changes of the oxide electrodes. The lithium insertion reaction of both oxides consists of two main steps. In the first step of Li x Nb 1.3V 0.7O 5 ( x=0∼1), the chemical diffusion coefficient D̃ of lithium was found to be on the order of 10 −11cm 2s, however in the second step ( x=1∼1.7) the D̃ value increased considerably to 10 −9∼10 −10cm 2s. On the other hand, for Li x Nb 1.5V 0.5O 5 ( x=0∼2) the D̃ value was mainly in the order of 10 −11 cm 2s. The self-diffusion coefficient D Li derived from the D̃ values was found to be on the order of 10 −12cm 2s in both oxides. Lithium was inserted in the crystal lattice while keeping the original crystal lattice arrangement. The largest unit cell volume (0.9409 nm 3) of Nb 1.3V 0.7O 5 among various Nb 2- n V n O 5 ( n=0.2∼0.8) and the increases in the cell volume and the crystallite size with lithium insertion may be related to higher diffusitivy of lithium in the crystal lattice of Li x Nb 1.3V 0.7O 5 ( x=1∼1.5).

The group theory of shear induced pair radial distribution functions in atomic liquids

Angular resolution of the pair radial distribution function in computer simulations of shear induced thickenening in atomic (Lennard-Jones) liquids has revealed the presence of anisotropic local structure which is explained on the basis of group theoretical statistical mechanics. This explains the observed structural asymmetry from the basic assumption that the symmetry of allowed ensemble averages in the steady state in the presence of shear is the same as that of the applied strain rate. The computer simulation results are reproduced from group theory by assuming that the crystal like lattice arrangement of atoms which appear in the simulations under shear can be described by some of the thirty two crystallographic point groups, namely hexagonal, trigonal, and triclinic. The hexagonal lattice symmetries C3h and C6h; the trigonal symmetry S6; and the triclinic symmetry Ci(S2) are found to support the crystal-like structures necessary to explain the observed angular resolution of the pair radial distribution function.