Lattice Interaction Research Articles

Exploring the polymorphism of selective androgen receptor modulator YK11

[(17α,20E)-17,20-[(1-methoxyethylidene)bis(oxy)]-3-oxo-19-norpregna-4,20-diene-21-carboxylic acid methyl ester], widely known under the name of YK11 is a synthetic agent with anabolic properties which belongs to the selective androgen receptor modulators group (SARMs). An extended polymorph screening was accomplished and the crystal structures of three YK11 polymorphs were determined by single crystal X-ray diffraction. The crystal features were analyzed by means of crystal lattice and intermolecular interaction energies as well. Furthermore, the polymorphs were investigated by powder X-ray diffraction, Fourier-Transform infrared spectroscopy and DSC thermal analysis.

Competing quantum spin liquids, gauge fluctuations, and anisotropic interactions in a breathing pyrochlore lattice

We use the projective symmetry group analysis to classify the quantum spin liquids on the $S=1/2$ pyrochlore magnet with a breathing anisotropy. We find 40 $\mathbb{Z}_2$ spin liquids and 16 $U(1)$ spin liquids that respect the $F\bar{4}3m$ space group and the time reversal symmetry. As an application, we consider the antiferromagnetic Heisenberg model, which is proposed to be the dominant interaction in the candidate material Ba$_3$Yb$_2$Zn$_5$O$_{11}$. Focusing on the $U(1)$ spin liquid ansatze, we find that only two of them are physical when restricted to this model. We present an analytical solution to the parton mean field theory for each of these two $U(1)$ spin liquids. It is revealed that one of them has gapless, while the other one has gapped, spinon excitations. The two $U(1)$ spin liquids are equal in energy regardless of the degree of breathing anisotropy, and they can be differentiated by the low-temperature heat capacity contribution from the quadratically-dispersing gapless spinons. We further show that the latter is unaffected by fluctuations of the $U(1)$ gauge field within the random phase approximation. Finally, we demonstrate that a small Dzyaloshinskii-Moriya interaction lifts the degeneracy between the two $U(1)$ spin liquids, and it eventually causes the lattice to decouple into independent tetrahedra at strong coupling. While current model parameters for Ba$_3$Yb$_2$Zn$_5$O$_{11}$ place it indeed in the decoupled regime, other candidate materials may be synthesised in the near future that realize the spin liquid states discussed in our work.

Spin-dependent polaron transport in helical molecules

We study thermal effects on spin transport along a deformable helical molecule in the presence of chiral-induced spin–orbit coupling. The carrier–lattice interaction is modeled by the well-established Peyrard–Bishop–Holstein model within the Langevin approach to include temperature as a stochastic noise. The carrier–lattice interaction causes the occurrence of polaron states in the molecule. We demonstrate the existence of two well-differentiated spin-dependent polaron transport regimes as a function of temperature. In the low-temperature regime, the spatial separation of the two spin-dependent polaron wave-packets results in a nonzero spin current. On the contrary, the spin current becomes negligible if the temperature of the system is high enough. Finally, we characterize this transition and estimate the critical temperature at which it takes place.

Tautomerization of diazenehydrazine via single proton tautomerization, spectral, XRD/HSA-interactions, optical and DFT/TD-DFT of new hydrazine ligand

A novel methyl (Z)-2-(2-(2-oxonaphthalen-1(2H)-ylidene)hydrazineyl)benzoate isomer ligand has been prepared instead of (E)-methyl 2-((2-hydroxynaphthalen-1-yl)diazenyl)benzoate isomer in very good yield. The tautomerization of diazene to hydrazine was computed via DFT; the single proton tautomerization S(6) process was confirmed by XRD. Moreover, the XRD-crystal measurements supported the hydrazine form as the preferred kinetic isomer; the structure of the desired ligand was also examined by IR, UV–vis., Carbon, Hydrogen and Nitrogen elemental analysis (CHN-EA), and NMR. Hirshfeld surface analysis (HSA) computation was performed to support the lattice interactions resulting by X-ray diffraction (XRD) measurement. Furthermore, the time-dependent density functional theory (TD-DFT) and B3LYP/IR computation were used to support the UV–visible as well as FT-IR experimental results.

Modulating Spin Polarization and Spin-Orbit Interaction by Submonolayer Engineering at LaAlO3/SrTiO3 Interfaces

Recently, the ${\mathrm{La}\mathrm{Al}\mathrm{O}}_{3}/{\mathrm{Sr}\mathrm{Ti}\mathrm{O}}_{3}$ (LAO/STO) interface has been highlighted as a major platform for spintronics, and its fundamental control of spin properties, therefore, becomes a key issue for application of this system. Here, we present a study showing the modulation of magnetic two-dimensional electron gases (2DEGs) with simultaneously enhanced spin-orbit interaction at the interface of LAO/STO by inserting ${\mathrm{La}\mathrm{Co}\mathrm{O}}_{3}$ submonolayers. At first, transport experiments provide evidence that Kondo behavior can be well controlled below about 13 K with the interlayer $\mathrm{Co}$ ions contributing as scattering centers. In addition, the systematic variation of the anomalous Hall effect obtained with increasing fraction of interfacial $\mathrm{Co}$ concentration below 10 K reveals that the spin polarization of 2DEGs is enhanced via submonolayer insertion. Simultaneously, we also observe an enlarged spin-orbit interaction at the buffered LAO/STO interface, resulting in a remarkably strong field-orientation-dependent magnetoresistance. Such tailored LAO/STO interfaces could potentially contribute to stronger spin-to-charge conversion responses and spin-torque measurements. Our observations indicate the subunit-cell insertion of functional layers to be a suitable route to tailor spin, orbital, and lattice interactions of the interfacial 2DEG, which makes the LAO/STO system an intriguing platform for spintronic applications.

First-principles calculation of the parameters used by atomistic magnetic simulations

While the ground state of magnetic materials is in general well described on the basis of spin density functional theory (SDFT), the theoretical description of finite-temperature and non-equilibrium properties require an extension beyond the standard SDFT. Time-dependent SDFT (TD-SDFT), which give for example access to dynamical properties are computationally very demanding and can currently be hardly applied to complex solids. Here we focus on the alternative approach based on the combination of a parameterized phenomenological spin Hamiltonian and SDFT-based electronic structure calculations, giving access to the dynamical and finite-temperature properties for example via spin-dynamics simulations using the Landau–Lifshitz–Gilbert (LLG) equation or Monte Carlo simulations. We present an overview on the various methods to calculate the parameters of the various phenomenological Hamiltonians with an emphasis on the KKR Green function method as one of the most flexible band structure methods giving access to practically all relevant parameters. Concerning these, it is crucial to account for the spin–orbit coupling (SOC) by performing relativistic SDFT-based calculations as it plays a key role for magnetic anisotropy and chiral exchange interactions represented by the DMI parameters in the spin Hamiltonian. This concerns also the Gilbert damping parameters characterizing magnetization dissipation in the LLG equation, chiral multispin interaction parameters of the extended Heisenberg Hamiltonian, as well as spin–lattice interaction parameters describing the interplay of spin and lattice dynamics processes, for which an efficient computational scheme has been developed recently by the present authors.

Atomically Thin Synapse Networks on Van Der Waals Photo-Memtransistors.

A new type of atomically thin synaptic network on van der Waals (vdW) heterostructures is reported, where each ultrasmall cell (≈2nm thick) built with trilayer WS2 semiconductor acts as a gate-tunable photoactive synapse, i.e., a photo-memtransistor. A train of UV pulses onto the WS2 memristor generates dopants in atomic-level precision by direct light-lattice interactions, which, along with the gate tunability, leads to the accurate modulation of the channel conductance for potentiation and depression of the synaptic cells. Such synaptic dynamics can be explained by a parallel atomistic resistor network model. In addition, it is shown that such a device scheme can generally be realized in other 2D vdW semiconductors, such as MoS2 , MoSe2 , MoTe2 , and WSe2 . Demonstration of these atomically thin photo-memtransistor arrays, where the synaptic weights can be tuned for the atomistic defect density, provides implications for a new type of artificial neural networks for parallel matrix computations with an ultrahigh integration density.

Three-body Faddeev calculations for and hypernuclei* *M.R.H. was Supported by the National Science Foundation under Grant No. NSF-PHY-2000029 with Central State University

We study the ground-state properties of the double hyperon for and nuclei in a three-body model . We solve two coupled Faddeev equations corresponding to the three-body configurations and in configuration space with the hyperspherical harmonics expansion method by employing the most recent hyperon-hyperon interactions obtained from lattice QCD simulations. Our numerical analysis for , using three lattice interaction models, leads to a ground state binding energy in the MeV domain and the separations and in the domains of fm and fm, respectively. The binding energy of the double- hypernucleus leads to MeV and consequently to smaller separations fm and fm. In addition to geometrical properties, we study the structure of ground-state wave functions and show that the main contributions are from the wave channels. Our results are consistent with the existing theoretical and experimental data.

Importance of the donor unit on fluoranthene for selective detection of nitro aromatic explosives

In this work, two aggregation-induced emission enhancement (AIEE) materials encompassing phenyl (M1) and thiophene (T1) units flanked to fluoranthene were synthesized. We report a new packing polymorphic phase of M1 and the molecular interactions in the crystal lattice were stabilized by CH···π (2.882 Å) interactions. Single crystal X-ray diffraction (SXRD) studies revealed that high torsional angles of phenyl/thiophene unit on the fluoranthene endow weak π-π intermolecular interactions in the crystal lattice. The photophysical properties of M1 and T1 were explored in solution, solid-state and their AIEE phenomenon was studied in THF/water systems. Both the compounds show strong sky-blue emission at 453 nm (M1) and 460 nm (T1). The fluorescence lifetime and quantum yields are varied significantly in the aggregated form. The emission enhancement ascribed due to restricted intramolecular rotation (RIR) of thiophene/phenyl with central π-conjugated fluoranthene in the aggregation state. Distinct changes in the surface morphology, variation in the photophysical properties and energy levels by varying the THF/water ratios furnish its potential towards trace detection of different nitroaromatics. Both materials show high sensitivity and selectivity towards detection of Trinitrophenol (TNP), however, T1 showed a high quenching rate constant at fw = 90 % (KSV = 5.81 × 104 M−1) with LOD of 0.6 ppm at fw = 70 %. The observed fluorescence quenching is attributed due to photoinduced electron transfer from fluoranthene to nitroaromatics through static quenching process. The remarkable efficiency of these fluorescent probes were further explored towards the analysis of river/tap water samples, suggesting their high potential for use in field analysis.

Lattice dynamics and spin–phonon coupling in the noncollinear antiferromagnetic antiperovskite Mn[formula omitted]NiN

Antiferromagnetic antiperovskites, of the form Mn3BN (B= Ni, Cu, Zn, Sn, Ir, and Pt), have shown an outstanding behavior in which, giant negative thermal expansion and chiral magnetic structures are intertwined. As such, aiming to shed light on the magnetostructural behavior, related to the magnetic ordering and crystalline structure of this type of materials, we studied theoretically, based-on first-principles calculations, the lattice dynamics and spin–phonon coupling in the Manganese-based antiperovskite Mn3NiN, as a prototype in the Mn3BN family. We found a strong spin–lattice coupling by means of the understanding of the phonon-dispersion curves obtained when including the chiral noncollinear magnetic structures. To do so, we highlight the importance of the exchange–correlation scheme selected and its influence on the structural, electronic, magnetic, and vibrational degrees of freedom. Finally, we found two unstable vibrational modes at the M- and R-points when the magnetic ordering is switched to ferromagnetic from the chiral Γ4g and Γ5g. These octahedral-associated modes with spin–phonon coupling parameters, λ, as large as 10.74 cm−1 and −2.53 cm−1 for the R5−, and M2+, respectively. The latter coupling is observed as a key signature of the strong spin–lattice interaction.

Exceptionally high selectivity in the separation of light hydrocarbons by adsorption on MIL-127(Fe) and on a (9,9) carbon nanotube

Porous solids with channel sizes that are not much above the size of small hydrocarbons can yield extremely large adsorption selectivity. Our Grand Canonical Monte-Carlo simulations indicate exceptionally high selectivity for the separation of methane, ethane and propane from natural gas. At 250 K the C3H8/CH4 separation on MIL-127 at low pressure has a selectivity of more than 1000 and the C3H8/CH4 separation on CNT (9,9) is even above 2000. This is due to the strong molecule lattice interaction in narrow channels which leads to large enthalpies of adsorption. The Arrhenius law for the Henry coefficients is analysed in order to show that the effect is due to this enthalpy rather than to steric reasons.

Localized Spin Dimers and Structural Distortions in the Hexagonal Perovskite Ba3CaMo2O9.

Extended solid-state materials based on the hexagonal perovskite framework are typified by close competition between localized magnetic interactions and quasi-molecular electronic states. Here, we report the structural and magnetic properties of the new six-layer hexagonal perovskite Ba3CaMo2O9. Neutron diffraction experiments, combined with magnetic susceptibility measurements, show that the Mo2O9 dimers retain localized character down to 5 K and adopt nonmagnetic spin-singlet ground states. This is in contrast to the recently reported Ba3SrMo2O9 analogue, in which the Mo2O9 dimers spontaneously separate into a mixture of localized and quasi-molecular ground states. Structural distortions in both Ba3CaMo2O9 and Ba3SrMo2O9 have been studied with the aid of distortion mode analyses to elucidate the coupling between the crystal lattice and electronic interactions in 6H Mo5+ hexagonal perovskites.

Physicochemical and biological studies of Ni(II), Cu(II) and Zn(II) ternary complexes of sulfaquinoxaline and 2,2’-bipyrimidine

Three monomeric ternary complexes of Ni(II) (1), Cu(II) (2), and Zn(II) (3) with sulfaquinoxaline (SQO), and 2,2’-bipyrimidine (bpm) as ligands have been prepared and their crystal structures have been determined. The complexes are formulated as M(SQO)2bpm·2H2O, completing MN6 coordination spheres. Hirshfeld surface analysis was employed to study the intermolecular interactions in the crystal lattices of the compounds. From these studies, it was found that hydrogen bonding and π-stacking interactions play an important role. Besides, the complexes have been characterized by FTIR and UV-Visible spectroscopies, and thermogravimetric techniques. The cytotoxicity of the complexes was screened against the tumoral A549 (human lung adenocarcinoma) and MG-63 (human osteosarcoma) cell lines. The complexes showed enhanced antibacterial activity against S. aureus and S. epidermidis as compared with the free SQO ligand.

Nano- and Crystal Engineering Approaches in the Development of Therapeutic Agents for Neoplastic Diseases

Cancer is a leading cause of death worldwide. It is a global quandary that requires the administration of many different active pharmaceutical ingredients (APIs) with different characteristics. As is the case with many APIs, cancer treatments exhibit poor aqueous solubility which can lead to low drug absorption, increased doses, and subsequently poor bioavailability and the occurrence of more adverse events. Several strategies have been envisaged to overcome this drawback, specifically for the treatment of neoplastic diseases. These include crystal engineering, in which new crystal structures are formed to improve drug physicochemical properties, and/or nanoengineering in which the reduction in particle size of the pristine crystal results in much improved physicochemical properties. Co-crystals, which are supramolecular complexes that comprise of an API and a co-crystal former (CCF) held together by non-covalent interactions in crystal lattice, have been developed to improve the performance of some anti-cancer drugs. Similarly, nanosizing through the formation of nanocrystals and, in some cases, the use of both crystal and nanoengineering to obtain nano co-crystals (NCC) have been used to increase the solubility as well as overall performance of many anticancer drugs. The formulation process of both micron and sub-micron crystalline formulations for the treatment of cancers makes use of relatively simple techniques and minimal amounts of excipients aside from stabilizers and co-formers. The flexibility of these crystalline formulations with regards to routes of administration and ability to target neoplastic tissue makes them ideal strategies for effectiveness of cancer treatments. In this review, we describe the use of crystalline formulations for the treatment of various neoplastic diseases. In addition, this review attempts to highlight the gaps in the current translation of these potential treatments into authorized medicines for use in clinical practice.

Synthesis, Spectroscopic, Crystal Structure, DFT, Hirshfeld Surface and Molecular Docking Analysis of Hexahydroquinoline Derivative (HQ)

The synthesis of a HQ derivative using a one-pot multicomponent synthesis is reported. Single crystal X-Ray diffraction at 293 K was used to characterize the material, which was then investigated theoretically using the DFT method. The 3 D Hirshfeld surface and 2 D fingerprint plots were created and linked with the XRD results to elucidate intermolecular interactions in the crystal lattice. In addition, FT-IR, UV-Vis, 1H, and 13 C were used to support the synthesis. Theoretical data calculated via DFT/6-311++G(d,p) level, matched to experimental single crystal X-ray diffraction bond lengths and bond angle parameters, NMR and FT-IR spectra, coincides with experimental data. The time dependent (TD-DFT) results correlates with the experimental electronic absorption measurements. Mulliken population analysis, Molecular Electrostatic Potential analysis (MEP), and Electron Localization Function (ELF) study were also performed. TD-DFT and HOMO/LUMO computations were used to examine the electron transport. Molecular docking using 7 protein receptors and drug Likeness were used to find the best ligand-protein interactions.

Ultrananoporous supercapacitor with ionic liquid comprised of two-site cation: an Ising model study (II)

A four-state one-dimension discrete spin model with the nearest neighbor and partial next nearest neighbor lattice interactions is proposed for describing electrical double layer formed by ionic liquid in cylindrical pore that can accommodate only one row of particles. The model, in which cation is modeled as a dimer formed by two hard spheres (HSs): one is positively charged with diameter , while the other is neutral with diameter , and anion is modeled by charged HS with diameter , is designed to investigate effects of pore diameter , ion transfer free energy, ion size and electrical valence on behaviors of specific differential capacitance and specific energy storage and its saturation value . Relevant Kramers–Wannier transfer matrix is , which gives system partition function by numerically solving maximum real root of the relevant characteristic equation. Main findings are briefly described below. (i) The ion valence has little effect on the value, but does reduce the threshold voltage strength , beyond which the energy storage reaches . However, the ion valence (whether co- or counter-ion) raises both the and values as the relevant ion size decreases enough. (ii) Decreasing of the value weakly reduces the value, but raises the peak height and the value obviously; correlation between the value and value becomes stronger with the ions getting more pore hostile. (iii) With the counter-ion or co-ion charged site size decreasing, both the value and value rise. However, the effect of the co-ion charged site size is weakened as the co-ion gets more pore hostile, and the cation neutral site size influences on the value less than the cation charged site size does. (iv) Pore friendly co-ion or pore hostile counter-ion always helps in raising the value; the two have significant synergistic effect with the co-ion pore friendliness playing more important role than the counter-ion pore hostility.

Host lipids required for Membrane protein matrix formation in new severe acute respiratory syndrome‐related coronavirus (SARS‐CoV‐2), ribonucleocapsid packaging and viral assembly

The current model of SARS‐CoV‐2 assembly proposes a multistage process: (i) the viral RNA coated with the nucleoprotein (N) forms the ribonucleoprotein (RNP), (ii) traffics to the endoplasmic reticulum‐Golgi apparatus intermediate compartment (ERGIC)‐derived vesicles to (iii) interact with the membrane (M) assembled along with spike (S) and envelope (E) proteins. Coronaviruses’ M has been described as required for new virus particle assembly. To date, biochemical and structural information on M are unavailable and key host factors required for M lattice formation, trafficking and interaction with the RNP are poorly characterized. The objective of this research project is to progress our understanding of SARS‐CoV‐2 assembly. Our central hypothesis is that M through its interaction with host lipids coordinates viral protein interactions and RNP packaging as key processes for SARS‐CoV‐2 assembly and spread. The role of lipids as molecules regulating the viral life cycle is poorly investigated.Our current data demonstrates a clear binding of cell expressed M to a Golgi resident sphingolipid. Furthermore, mutations at the sphingolipid binding motif resulted in deficient pull down of M protein by sphingolipid coated beads. In cells, the M sphingolipid‐binding mutant failed to retain S protein at viral assembly membranes resulting in a reduced entry capacity of newly formed virus‐like particles. Our current study is providing a first insight on the direct role of host lipids during SARS‐CoV‐2 assembly, orchestrated by the M protein.

Dielectric properties of hydrogen-bonded cesium dihydrogen phosphate-type ferroelectric crystals

Cesium dihydrogen phosphate crystal belongs to the potassium dihydrogen phosphate family of ferroelectrics. It is ferroelectric below 154 K. It shows a large isotope effect like other members of this family. We have modified two-sublattice pseudospin lattice coupled-mode model Hamiltonian by adding phonon anharmonic interactions, extra-spin lattice interactions, and direct spin-spin coupling as well as an electric field. By using modified model Hamiltonian, double-time thermal Green function method and following the Zubarev and Kubo formalism, we have derived theoretically expressions for soft mode frequency, dielectric constant, and loss tangent for cesium dihydrogen phosphate (CDP)-type ferroelectric crystals. By fitting model values of physical parameters, we have calculated thermal variations of normal mode frequency, dielectric constant, and dielectric tangent loss for CDP-crystal. We have compared our theoretical results with the experimental results of others. Our theoretical obtainedresults agree well with the experimental results of others.

Understanding the synergistic effect of bimetallic Cu2O-ZnO nanocomposites for the antimicrobial activity and facile synthesis of phenyl xanthenedione: A comparative study

Herein, we have described one pot synthesis of Cu2OZnO nanocomposites via green route using Callistemon viminalis aqueous leaf extract first for antimicrobial applications and facile synthesis of phenyl xanthenedione. FTIR spectroscopic study of Cu2O-ZnO NCs was carried out to confirm bioreduction of copper and zinc ions by biomolecules present in leaf extract. Elemental composition was detected by Energy Dispersive X-ray spectral study whereas powder XRD analysis revealed nanosize and lattice interaction in the bimetallic composite. Biosynthesized nanocomposites were also screened by SEM, TEM and TGA/DTA techniques. Purity and presence of oxides of copper and zinc in the product had been investigated by X-ray Photoelectron spectroscopy (XPS). Furthermore, synergistic effect of copper and zinc was examined by comparing antimicrobial (against S.aureus, P.aeruginosa and Candida albicans) and catalytic activity (for Phenylxanthenedione synthesis) of Cu2O-ZnO nanocomposites with that of Cu2O nanoparticles. The results indicate that Cu2O-ZnO nanocomposites possess more potential as compared to Cu2O nanoparticles.

Strained Zero‐Valent Iron for Highly Efficient Heavy Metal Removal

AbstractMicroscale zero‐valent iron is one of the most important multifunctional environmental remediation materials, yet its passivated iron oxide shell hampers the transportation of inherent electrons. Herein, the authors exert tensile strain onto mZVI by interstitial boron doping that destabilizes lattice FeFe interactions, thereby liberating the electrons trapped in the iron reservoir. Tensile strain also upshifts the equilibrated Fermi level at the iron/iron oxide Ohmic heterojunction, thus populating the oxide shell with abundant electrons for robust heavy metal sequestration. Strained‐mZVI exhibits a 62 times faster Cr(VI) removal rate than its unstrained counterpart and can successfully treat industrial wastewater such as landfill leachate, electroplating, and chromium effluents. The excellent property and exceedingly low cost ($2000 ton−1) of strained‐mZVI results in its great potential to remediate heavy metal‐contaminated water and soil.